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-rw-r--r--tests/README.md2
-rw-r--r--tests/by-name/at/atuin-sync/test.nix191
-rw-r--r--tests/by-name/ba/back/test.nix147
-rw-r--r--tests/by-name/dn/dns/test.nix129
-rw-r--r--tests/by-name/em/email-dns/nodes/mail_server.nix52
-rw-r--r--tests/by-name/em/email-dns/nodes/name_server.nix292
-rw-r--r--tests/by-name/em/email-dns/nodes/user.nix70
-rw-r--r--tests/by-name/em/email-dns/test.nix167
-rw-r--r--tests/by-name/em/email-http/nodes/mail_server.nix57
-rw-r--r--tests/by-name/em/email-http/nodes/user.nix26
-rw-r--r--tests/by-name/em/email-http/test.nix100
-rw-r--r--tests/by-name/em/email-ip/test.nix174
-rw-r--r--tests/by-name/ru/rust-motd/test.nix62
-rw-r--r--tests/by-name/sh/sharkey-cpu/test.nix81
-rw-r--r--tests/by-name/sh/sharkey/test.nix102
-rw-r--r--tests/by-name/ta/taskchampion-sync/test.nix151
-rwxr-xr-xtests/common/acme/certs/generate66
-rwxr-xr-xtests/common/acme/certs/generate.ca38
-rwxr-xr-xtests/common/acme/certs/generate.client44
-rw-r--r--tests/common/acme/certs/output/acme.test.cert.pem11
-rw-r--r--tests/common/acme/certs/output/acme.test.key.pem25
-rw-r--r--tests/common/acme/certs/output/acme.test.template5
-rw-r--r--tests/common/acme/certs/output/ca.cert.pem10
-rw-r--r--tests/common/acme/certs/output/ca.key.pem25
-rw-r--r--tests/common/acme/certs/output/ca.template5
-rw-r--r--tests/common/acme/certs/snakeoil-certs.nix13
-rw-r--r--tests/common/acme/client.nix21
-rw-r--r--tests/common/acme/default.nix47
-rw-r--r--tests/common/acme/server.nix91
-rw-r--r--tests/common/dns/client.nix10
-rw-r--r--tests/common/dns/server.nix43
-rw-r--r--tests/common/email/dkim/alice.com/private.age15
-rw-r--r--tests/common/email/dkim/alice.com/public1
-rw-r--r--tests/common/email/dkim/bob.com/private.age14
-rw-r--r--tests/common/email/dkim/bob.com/public1
-rwxr-xr-xtests/common/email/dkim/gen_key.sh35
-rw-r--r--tests/common/email/dkim/mail1.server.com/private.age15
-rw-r--r--tests/common/email/dkim/mail1.server.com/public1
-rw-r--r--tests/common/email/dkim/mail2.server.com/private.age15
-rw-r--r--tests/common/email/dkim/mail2.server.com/public1
-rw-r--r--tests/common/email/hostKey7
41 files changed, 2327 insertions, 35 deletions
diff --git a/tests/README.md b/tests/README.md
index 7811f32..aaa76b4 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -1,6 +1,6 @@
 # Tests
 
 This directory tree mirrors the modules defined in the
-[modules](%60../modules/%60) directory.  Each module should have at least
+[modules](%60../modules/%60) directory. Each module should have at least
 one test in the mirrored directory, effectively replacing the module's
 `module.nix` file.
diff --git a/tests/by-name/at/atuin-sync/test.nix b/tests/by-name/at/atuin-sync/test.nix
new file mode 100644
index 0000000..d29c031
--- /dev/null
+++ b/tests/by-name/at/atuin-sync/test.nix
@@ -0,0 +1,191 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}:
+nixos-lib.runTest {
+  hostPkgs = pkgs;
+  name = "atuin-sync";
+
+  node = {
+    specialArgs = {inherit pkgsUnstable vhackPackages nixpkgs-unstable nixLib;};
+
+    # Use the nixpkgs as constructed by the `nixpkgs.*` options
+    pkgs = null;
+  };
+
+  nodes = let
+    atuinSession = "01969ec6b8d07e30a9d2df0911fbfe2a";
+  in {
+    acme = {
+      imports = [
+        ../../../common/acme/server.nix
+        ../../../common/dns/client.nix
+      ];
+    };
+    name_server = {nodes, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../common/acme/client.nix
+          ../../../common/dns/server.nix
+        ];
+
+      vhack.dns.zones = {
+        "atuin-sync.server" = {
+          SOA = {
+            nameServer = "ns";
+            adminEmail = "admin@server.com";
+            serial = 2025012301;
+          };
+          useOrigin = false;
+
+          A = [
+            nodes.server.networking.primaryIPAddress
+          ];
+          AAAA = [
+            nodes.server.networking.primaryIPv6Address
+          ];
+        };
+      };
+    };
+
+    server = {config, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../../modules
+          ../../../common/acme/client.nix
+          ../../../common/dns/client.nix
+        ];
+
+      vhack = {
+        persist.enable = true;
+        nginx.enable = true;
+        atuin-sync = {
+          enable = true;
+          fqdn = "atuin-sync.server";
+        };
+      };
+    };
+
+    client1 = {config, ...}: {
+      imports = [
+        ../../../common/acme/client.nix
+        ../../../common/dns/client.nix
+      ];
+
+      environment.sessionVariables.ATUIN_SESSION = atuinSession;
+
+      environment.systemPackages = [
+        pkgs.atuin
+        pkgs.sqlite-interactive
+      ];
+    };
+    client2 = {config, ...}: {
+      imports = [
+        ../../../common/acme/client.nix
+        ../../../common/dns/client.nix
+      ];
+
+      environment.sessionVariables.ATUIN_SESSION = atuinSession;
+
+      environment.systemPackages = [
+        pkgs.atuin
+        pkgs.sqlite-interactive
+      ];
+    };
+  };
+
+  testScript = {nodes, ...}: let
+    syncLogin = pkgs.writeShellScript "login-atuin-sync-account" ''
+      atuin login --username syncy --password password1234 --key "$1"
+    '';
+
+    syncRegister = pkgs.writeShellScript "register-atuin-sync-account" ''
+      atuin register --username syncy --email syncy@email.com --password password1234
+    '';
+
+    mkSyncConfig = pkgs.writeShellScript "register-atuin-sync-account" ''
+      mkdir --parents ~/.config/atuin/
+      cat << EOF > ~/.config/atuin/config.toml
+      sync_address = "https://atuin-sync.server"
+
+      # Use the v2 sync
+      [sync]
+      records = true
+      EOF
+    '';
+
+    runCommandAndRecordInAtuin = pkgs.writeShellScript "run-command-and-record-in-atuin" ''
+      # SPDX-SnippetBegin
+      # SPDX-SnippetCopyrightText: 2023 mentalisttraceur (https://github.com/mentalisttraceur)
+      # Source: https://github.com/atuinsh/atuin/issues/1188#issuecomment-1698354107
+      run_and_record_in_atuin()
+      {
+          local id
+          local status
+          local escaped_command="$(printf '%q ' "$@")"
+          id="$(atuin history start -- "$escaped_command")"
+          "$@"
+          status=$?
+          atuin history end --exit $status "$id"
+          return $status
+      }
+      # SPDX-SnippetEnd
+
+      run_and_record_in_atuin "$@"
+    '';
+
+    acme = import ../../../common/acme {inherit pkgs;};
+  in
+    acme.prepare ["server" "client1" "client2"]
+    # Python
+    ''
+      server.wait_for_unit("atuin.service")
+      server.wait_for_open_port(443)
+
+      # Wait for the server to acquire the acme certificate
+      client1.wait_until_succeeds("curl https://atuin-sync.server")
+
+      with subtest("Setup client syncing"):
+          for client in [client1, client2]:
+            client.succeed("${mkSyncConfig}")
+
+          client1.succeed("${syncRegister}")
+
+          for client in [client1, client2]:
+            # See https://docs.atuin.sh/guide/sync/
+            client.succeed(f"${syncLogin} '{client1.succeed("atuin key")}'")
+
+      with subtest("Can import shell history"):
+          client1.succeed("${runCommandAndRecordInAtuin} echo hi - client 1")
+          client2.succeed("${runCommandAndRecordInAtuin} echo hi - client 2")
+
+      with subtest("Can sync tasks"):
+          for client in [client1, client2]:
+            client.succeed("atuin sync --force")
+          client1.succeed("atuin sync --force")
+
+
+      with subtest("Have correct tasks"):
+          hist1 = client1.succeed("atuin history list --session --format '{command}'").strip().split('\n')
+          hist2 = client2.succeed("atuin history list --session --format '{command}'").strip().split('\n')
+
+          hist1.sort()
+          hist2.sort()
+
+          canonicalHistory = [
+            "echo hi - client 1",
+            "echo hi - client 2"
+          ]
+
+          assert hist1 == hist2, f"The clients don't have the same amount of history items, client1: '{hist1}', client2: '{hist2}'"
+          assert hist1 == canonicalHistory, f"The history is not correct: '{hist1}' vs. '{canonicalHistory}'"
+    '';
+}
diff --git a/tests/by-name/ba/back/test.nix b/tests/by-name/ba/back/test.nix
index 63f2837..cce5ede 100644
--- a/tests/by-name/ba/back/test.nix
+++ b/tests/by-name/ba/back/test.nix
@@ -8,9 +8,19 @@
   nixLib,
   ...
 }: let
-  gitRepoPath = "/srv/test/repo";
-
   domain = "server";
+
+  sshKeys =
+    import ../../gi/git-server/ssh_keys.nix {inherit pkgs;};
+
+  gitoliteAdminConfSnippet = pkgs.writeText "gitolite-admin-conf-snippet" ''
+    repo CREATOR/[a-zA-Z0-9].*
+      C     = @all
+      RW+   = CREATOR
+      RW    = WRITERS
+      R     = READERS
+      option user-configs = cgit\.owner cgit\.desc cgit\.section cgit\.homepage
+  '';
 in
   nixos-lib.runTest {
     hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
@@ -26,7 +36,7 @@ in
 
     nodes = {
       server = {config, ...}: {
-        environment.systemPackages = [pkgs.git pkgs.git-bug pkgs.gawk];
+        environment.systemPackages = [pkgs.git];
 
         imports =
           extraModules
@@ -35,28 +45,41 @@ in
           ];
 
         vhack = {
+          persist.enable = true;
+          openssh.enable = true;
           nginx = {
             enable = true;
             selfsign = true;
           };
           git-server = {
             enable = true;
+            domain = "git.${domain}";
+            gitolite.adminPubkey = sshKeys.admin.pub;
           };
-          back = {
+          git-back = {
             enable = true;
-            repositories = {
-              "${gitRepoPath}" = {
-                enable = true;
-                domain = "${domain}";
-                port = 9220;
-              };
-            };
+            domain = "issues.${domain}";
           };
         };
       };
 
-      client = {...}: {
-        environment.systemPackages = [pkgs.curl];
+      client = {nodes, ...}: {
+        environment.systemPackages = [pkgs.git pkgs.curl pkgs.git-bug pkgs.gawk];
+        programs.ssh.extraConfig = ''
+          Host *
+            UserKnownHostsFile /dev/null
+            StrictHostKeyChecking no
+            # there's nobody around that can input password
+            PreferredAuthentications publickey
+        '';
+        users.users.alice = {isNormalUser = true;};
+        networking.hosts = {
+          "${nodes.server.networking.primaryIPAddress}" = [
+            "git.${domain}"
+            "issues.${domain}"
+            "${domain}"
+          ];
+        };
       };
     };
 
@@ -67,55 +90,111 @@ in
     ''
       start_all()
 
-      with subtest("can setup git-bug issues on server"):
-        server.succeed("${pkgs.writeShellScript "setup-git-repo" ''
-        set -ex
+      with subtest("can setup ssh keys on client"):
+        client.succeed(
+            "mkdir -p ~root/.ssh",
+            "cp ${sshKeys.admin.priv} ~root/.ssh/id_ed25519",
+            "chmod 600 ~root/.ssh/id_ed25519",
+        )
+        client.succeed(
+            "sudo -u alice mkdir -p ~alice/.ssh",
+            "sudo -u alice cp ${sshKeys.alice.priv} ~alice/.ssh/id_ed25519",
+            "sudo -u alice chmod 600 ~alice/.ssh/id_ed25519",
+        )
+
+      with subtest("gitolite server starts"):
+        server.wait_for_unit("gitolite-init.service")
+        server.wait_for_unit("sshd.service")
+        client.succeed("ssh -n git@git.${domain} info")
+
+
+      with subtest("admin can clone and configure gitolite-admin.git"):
+        client.succeed("${pkgs.writeShellScript "setup-gitolite-admin.git" ''
+        set -xe
+
+        git clone git@git.${domain}:gitolite-admin.git
+        git config --global user.name 'System Administrator'
+        git config --global user.email root\@domain.example
+
+        cp ${sshKeys.alice.pub} gitolite-admin/keydir/alice.pub
+
+        (cd gitolite-admin && git switch -c master && git branch -D main)
+
+        (cd gitolite-admin && git add . && git commit -m 'Add keys for alice' && git push -u origin master)
+        cat ${gitoliteAdminConfSnippet} >> gitolite-admin/conf/gitolite.conf
+        (cd gitolite-admin && git add . && git commit -m 'Add support for wild repos' && git push)
+        (cd gitolite-admin && git push -d origin main)
+      ''}")
 
-        mkdir --parents "${gitRepoPath}"
-        cd "${gitRepoPath}"
+      with subtest("alice can create a repo"):
+        client.succeed("sudo -u alice ${pkgs.writeShellScript "alice-create-repo" ''
+        set -xe
+
+        mkdir --parents ./alice/repo1 && cd alice/repo1;
+
+        git init --initial-branch main
+        echo "# Alice's Repo" > README.md
+        git add README.md
+        git -c user.name=Alice -c user.email=alice@domain.example commit -m 'Add readme'
 
-        git init
+        git remote add origin git@git.${domain}:alice/repo1.git
+        git push --set-upstream origin main
+      ''}")
+
+      with subtest("can setup git-bug issues in alice/repo1"):
+        client.succeed("sudo -u alice ${pkgs.writeShellScript "setup-git-repo" ''
+        set -ex
 
-        git bug user create --avatar "" --email "test@email.org" --name "test user" --non-interactive
+        cd alice/repo1
 
-        git bug add \
+        git bug user new --avatar "" --email "alice@server.org" --name "alice" --non-interactive
+
+        git bug bug new \
         --title "Some bug title" \
         --message "A long description of the bug. Probably has some code segments, maybe even *markdown* mark_up_ or other things" \
         --non-interactive
 
-        git bug add \
+        git bug bug new \
         --title "Second bug title" \
         --message "" \
         --non-interactive
 
-        git bug add \
+        git bug bug new \
         --title "Third bug title" \
         --message "" \
         --non-interactive
 
-        git bug select "$(git bug ls --format plain | awk '{print $1}' | head -n 1)"
+        git bug bug select "$(git bug bug --format plain | awk '{print $1}' | head -n 1)"
+
+        git bug bug comment new --message "Some comment message" --non-interactive
+        git bug bug comment new --message "Second comment message" --non-interactive
 
-        git bug comment add --message "Some comment message" --non-interactive
-        git bug comment add --message "Second comment message" --non-interactive
+        # TODO: This should use `git bug push`, but their ssh implementation is just
+        # too special to work in a VM test <2025-03-08>
+        git push origin +refs/bugs/*
+        git push origin +refs/identities/*
 
-        # NOTE(@bpeetz): Currently, the `back` module assumes that the git user can write
-        # to the repository, as such we need to provide write access here <2024-12-24>
-        chown --recursive git:git "${gitRepoPath}"
+        ssh git@git.${domain} -- config alice/repo1 --add cgit.owner Alice
+        ssh git@git.${domain} -- perms alice/repo1 + READERS @all
       ''}")
 
       with subtest("back server starts"):
-        server.wait_for_unit("${builtins.replaceStrings ["/"] ["_"] "back-${domain}.service"}")
+        server.wait_for_unit("back.service")
 
       with subtest("client can access the server"):
         client.succeed("${pkgs.writeShellScript "curl-back" ''
         set -xe
 
-        curl --insecure --silent --fail --show-error "https://${domain}/issues/open" --output /root/issues.html
-
-        grep -- '- 2 comments' /root/issues.html
+        curl --insecure --fail --show-error "https://issues.${domain}/alice/repo1/issues/?query=status:open" --output /root/issues.html
         grep -- 'Second bug title' /root/issues.html
-      ''}")
+
+        curl --insecure --fail --show-error "https://issues.${domain}/" --output /root/repos.html
+        grep -- 'repo' /root/repos.html
+        grep -- "&lt;No description&gt;" /root/repos.html
+        grep -- '<span class="user-name">Alice</span>' /root/repos.html
+      ''} >&2")
 
       client.copy_from_vm("/root/issues.html", "");
+      client.copy_from_vm("/root/repos.html", "");
     '';
   }
diff --git a/tests/by-name/dn/dns/test.nix b/tests/by-name/dn/dns/test.nix
new file mode 100644
index 0000000..01d8833
--- /dev/null
+++ b/tests/by-name/dn/dns/test.nix
@@ -0,0 +1,129 @@
+# Inspired by this file: /nixpkgs/nixos/tests/nsd.nix
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}: let
+  common = {...}: {
+    networking.firewall.enable = false;
+    networking.dhcpcd.enable = false;
+  };
+
+  mkClient = version: {
+    lib,
+    nodes,
+    ...
+  }: {
+    environment.systemPackages = [pkgs.dig pkgs.dig.dnsutils];
+
+    imports = [common];
+    networking.nameservers = lib.mkForce [
+      (lib.head nodes.server.networking.interfaces.eth1."${version}".addresses).address
+    ];
+  };
+in
+  nixos-lib.runTest {
+    hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
+
+    name = "dns";
+
+    node = {
+      specialArgs = {inherit pkgsUnstable vhackPackages nixpkgs-unstable nixLib;};
+
+      # Use the nixpkgs as constructed by the `nixpkgs.*` options
+      pkgs = null;
+    };
+
+    nodes = {
+      server = {
+        config,
+        lib,
+        ...
+      }: {
+        imports =
+          extraModules
+          ++ [
+            ../../../../modules
+            common
+          ];
+
+        vhack = {
+          dns = {
+            enable = true;
+            interfaces = [
+              (lib.head config.networking.interfaces.eth1.ipv4.addresses).address
+              (lib.head config.networking.interfaces.eth1.ipv6.addresses).address
+            ];
+            zones = {
+              "example.com" = {
+                SOA = {
+                  nameServer = "ns";
+                  adminEmail = "admin@example.com";
+                  serial = 2024012301;
+                };
+
+                useOrigin = false;
+                NS = [
+                  "ns.example.com."
+                ];
+
+                subdomains = {
+                  ns = {
+                    A = ["192.168.1.3"];
+                  };
+                  ipv4 = {
+                    A = ["1.2.3.4"];
+                  };
+                  ipv6 = {
+                    AAAA = ["dead:beef::1"];
+                  };
+                  openpgpkey = {
+                    TXT = ["Hi!"];
+                  };
+                };
+              };
+            };
+          };
+        };
+      };
+
+      clientV4 = mkClient "ipv4";
+      clientV6 = mkClient "ipv6";
+    };
+
+    testScript = {nodes, ...}:
+    /*
+    python
+    */
+    ''
+      start_all()
+
+      clientV4.wait_for_unit("network.target")
+      clientV6.wait_for_unit("network.target")
+      server.wait_for_unit("nsd.service")
+
+      def assert_host(ipVersion, dnsRecordType, dnsQuery, expected):
+          self = clientV4 if ipVersion == 4 else clientV6
+          out = self.succeed(f"host -{ipVersion} -t {dnsRecordType} {dnsQuery}").rstrip()
+          self.log(f"output: {out}")
+          import re
+          assert re.search(expected, out), f"DNS IPv{ipVersion} dnsQuery on {dnsQuery} gave '{out}' instead of '{expected}'"
+
+
+      for ipv in 4, 6:
+          with subtest(f"IPv{ipv}"):
+              assert_host(ipv, "a", "example.com", "has no [^ ]+ record")
+              assert_host(ipv, "aaaa", "example.com", "has no [^ ]+ record")
+
+              assert_host(ipv, "soa", "example.com", "SOA.*?admin\\.example\\.com")
+              assert_host(ipv, "a", "ipv4.example.com", "address 1.2.3.4$")
+              assert_host(ipv, "aaaa", "ipv6.example.com", "address dead:beef::1$")
+
+              assert_host(ipv, "txt", "openpgpkey.example.com", "descriptive text \"Hi!\"$")
+    '';
+  }
diff --git a/tests/by-name/em/email-dns/nodes/mail_server.nix b/tests/by-name/em/email-dns/nodes/mail_server.nix
new file mode 100644
index 0000000..279d289
--- /dev/null
+++ b/tests/by-name/em/email-dns/nodes/mail_server.nix
@@ -0,0 +1,52 @@
+{
+  extraModules,
+  pkgs,
+  vhackPackages,
+}: {
+  mkMailServer = serverName: principal: {
+    config,
+    lib,
+    nodes,
+    ...
+  }: {
+    imports =
+      extraModules
+      ++ [
+        ../../../../../modules
+        ../../../../common/acme/client.nix
+        ../../../../common/dns/client.nix
+      ];
+
+    environment.systemPackages = [
+      pkgs.bind
+      pkgs.openssl
+    ];
+
+    age.identityPaths = ["${../../../../common/email/hostKey}"];
+
+    vhack = {
+      stalwart-mail = {
+        enable = true;
+        fqdn = "${serverName}.server.com";
+        admin = "admin@${serverName}.server.com";
+        security = {
+          dkimKeys = let
+            loadKey = name: {
+              dkimPublicKey = builtins.readFile (../../../../common/email/dkim + "/${name}/public");
+              dkimPrivateKeyPath = ../../../../common/email/dkim + "/${name}/private.age";
+              keyAlgorithm = "ed25519-sha256";
+            };
+          in {
+            "mail1.server.com" = loadKey "mail1.server.com";
+            "mail2.server.com" = loadKey "mail2.server.com";
+            "alice.com" = loadKey "alice.com";
+            "bob.com" = loadKey "bob.com";
+          };
+          verificationMode = "strict";
+        };
+        openFirewall = true;
+        principals = [principal];
+      };
+    };
+  };
+}
diff --git a/tests/by-name/em/email-dns/nodes/name_server.nix b/tests/by-name/em/email-dns/nodes/name_server.nix
new file mode 100644
index 0000000..bde1a16
--- /dev/null
+++ b/tests/by-name/em/email-dns/nodes/name_server.nix
@@ -0,0 +1,292 @@
+{extraModules}: {
+  config,
+  lib,
+  nodes,
+  pkgs,
+  ...
+}: let
+  keyAlgoToKeyType = keyAlgo:
+    if keyAlgo == "ed25519-sha256"
+    then "ed25519"
+    else if keyAlgo == "rsa-sha-256" || keyAlgo == "rsa-sha-1"
+    then "rsa"
+    else builtins.throw "Impossible";
+
+  mkZone = user: nodes: lib: cfg: {
+    SOA = {
+      nameServer = "ns.server.com";
+      adminEmail = "${user}@${user}.com";
+      serial = 2024012301;
+    };
+
+    MX = [
+      {
+        preference = 10;
+        exchange = "${cfg.fqdn}.";
+      }
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc8461.html#section-3.1
+    # Also see the policy in the hmtl part.
+    MTA-STS = [
+      {
+        id = "20250228Z";
+      }
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc7208.html
+    # https://en.wikipedia.org/wiki/Sender_Policy_Framework
+    TXT = [
+      (builtins.concatStringsSep " "
+        [
+          "v=spf1" # The version.
+          "+mx" # Allow mail from this domain MX record.
+          "-all" # Reject all other emails if the previous mechanism did not match.
+        ])
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc6376.html#section-3.6.1
+    # https://www.rfc-editor.org/rfc/rfc6376.html#section-7.5
+    DKIM = [
+      {
+        selector = "mail";
+        k = keyAlgoToKeyType cfg.security.dkimKeys."${user}.com".keyAlgorithm;
+        p = cfg.security.dkimKeys."${user}.com".dkimPublicKey;
+        s = ["email"];
+        t = ["s"];
+      }
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc7489.html#section-6.3
+    DMARC = [
+      {
+        adkim = "strict";
+        aspf = "strict";
+        fo = ["0" "1" "d" "s"];
+        p = "reject";
+        rua = cfg.admin;
+        ruf = [cfg.admin];
+      }
+    ];
+
+    A = [
+      nodes.${user}.networking.primaryIPAddress
+    ];
+    AAAA = [
+      nodes.${user}.networking.primaryIPv6Address
+    ];
+  };
+  mkServerZone = serverName: nodes: lib: let
+    cfg = nodes."${serverName}_server".vhack.stalwart-mail;
+  in {
+    SOA = {
+      nameServer = "ns.server.com";
+      adminEmail = "admin@server.com";
+      serial = 2024012301;
+    };
+    MX = [
+      {
+        preference = 10;
+        exchange = "${serverName}.server.com.";
+      }
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc6376.html#section-3.6.1
+    # https://www.rfc-editor.org/rfc/rfc6376.html#section-7.5
+    DKIM = [
+      {
+        selector = "mail";
+        k = keyAlgoToKeyType cfg.security.dkimKeys."${serverName}.server.com".keyAlgorithm;
+        p = cfg.security.dkimKeys."${serverName}.server.com".dkimPublicKey;
+        s = ["email"];
+        t = ["s"];
+      }
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc7489.html#section-6.3
+    DMARC = [
+      {
+        adkim = "strict";
+        aspf = "strict";
+        fo = ["0" "1" "d" "s"];
+        p = "quarantine";
+        rua = cfg.admin;
+        ruf = [cfg.admin];
+      }
+    ];
+
+    # https://www.rfc-editor.org/rfc/rfc7208.html
+    # NOTE(@bpeetz): This server might not be directly sending mail, but it is still required for
+    # the SMTP EHLO check. <2025-02-25>
+    TXT = [
+      (builtins.concatStringsSep " "
+        [
+          "v=spf1" # The version.
+          "+mx" # Allow mail from this domain MX record.
+          "-all" # Reject all other emails if the previous mechanism did not match.
+        ])
+    ];
+
+    A = [
+      nodes."${serverName}_server".networking.primaryIPAddress
+    ];
+    AAAA = [
+      nodes."${serverName}_server".networking.primaryIPv6Address
+    ];
+  };
+in {
+  imports =
+    extraModules
+    ++ [
+      ../../../../../modules
+      ../../../../common/acme/client.nix
+      ../../../../common/dns/server.nix
+    ];
+
+  services.nginx = {
+    logError = "stderr debug";
+    virtualHosts = let
+      mkStsHost = mx: {
+        forceSSL = true;
+        enableACME = true;
+        root = pkgs.runCommandLocal "mkPolicy" {} ''
+          mkdir --parents $out/.well-known/
+
+          # https://www.rfc-editor.org/rfc/rfc8461.html#section-3.2
+          cat << EOF > $out/.well-known/mta-sts.txt
+          version: STSv1
+          mode: enforce
+          mx: ${mx}
+          max_age: 604800
+          EOF
+        '';
+      };
+    in {
+      "mta-sts.alice.com" = mkStsHost "mail2.server.com";
+      "mta-sts.bob.com" = mkStsHost "mail1.server.com";
+    };
+  };
+
+  vhack = {
+    nginx = {
+      enable = true;
+    };
+    dns.zones = let
+      stsZone = {
+        SOA = {
+          nameServer = "ns";
+          adminEmail = "admin@server.com";
+          serial = 2025012301;
+        };
+
+        useOrigin = false;
+
+        A = [
+          nodes.name_server.networking.primaryIPAddress
+        ];
+        AAAA = [
+          nodes.name_server.networking.primaryIPv6Address
+        ];
+      };
+    in {
+      "arpa" = {
+        SOA = {
+          nameServer = "ns";
+          adminEmail = "admin@server.com";
+          serial = 2025012301;
+        };
+        useOrigin = false;
+
+        PTR = [
+          {
+            name = "acme.test";
+            ip.v4 = nodes.acme.networking.primaryIPAddress;
+          }
+          {
+            name = "acme.test";
+            ip.v6 = nodes.acme.networking.primaryIPv6Address;
+          }
+
+          {
+            name = "alice.com";
+            ip.v4 = nodes.alice.networking.primaryIPAddress;
+          }
+          {
+            name = "alice.com";
+            ip.v6 = nodes.alice.networking.primaryIPv6Address;
+          }
+
+          {
+            name = "bob";
+            ip.v4 = nodes.bob.networking.primaryIPAddress;
+          }
+          {
+            name = "bob";
+            ip.v6 = nodes.bob.networking.primaryIPv6Address;
+          }
+
+          {
+            name = "mail1.server.com";
+            ip.v4 = nodes.mail1_server.networking.primaryIPAddress;
+          }
+          {
+            name = "mail1.server.com";
+            ip.v6 = nodes.mail1_server.networking.primaryIPv6Address;
+          }
+
+          {
+            name = "mail2.server.com";
+            ip.v4 = nodes.mail2_server.networking.primaryIPAddress;
+          }
+          {
+            name = "mail2.server.com";
+            ip.v6 = nodes.mail2_server.networking.primaryIPv6Address;
+          }
+
+          {
+            name = "ns.server.com";
+            ip.v4 = nodes.name_server.networking.primaryIPAddress;
+          }
+          {
+            name = "ns.server.com";
+            ip.v6 = nodes.name_server.networking.primaryIPv6Address;
+          }
+        ];
+      };
+
+      "alice.com" = mkZone "alice" nodes lib nodes.mail2_server.vhack.stalwart-mail;
+      "mta-sts.alice.com" = stsZone;
+      "bob.com" = mkZone "bob" nodes lib nodes.mail1_server.vhack.stalwart-mail;
+      "mta-sts.bob.com" = stsZone;
+      "mail1.server.com" = mkServerZone "mail1" nodes lib;
+      "mail2.server.com" = mkServerZone "mail2" nodes lib;
+      "ns.server.com" = {
+        SOA = {
+          nameServer = "ns";
+          adminEmail = "admin@server.com";
+          serial = 2025012301;
+        };
+        useOrigin = false;
+
+        A = [
+          nodes.name_server.networking.primaryIPAddress
+        ];
+        AAAA = [
+          nodes.name_server.networking.primaryIPv6Address
+        ];
+      };
+      "server.com" = {
+        SOA = {
+          nameServer = "ns";
+          adminEmail = "admin@server.com";
+          serial = 2025012301;
+        };
+
+        useOrigin = false;
+        NS = [
+          "ns.server.com."
+        ];
+      };
+    };
+  };
+}
diff --git a/tests/by-name/em/email-dns/nodes/user.nix b/tests/by-name/em/email-dns/nodes/user.nix
new file mode 100644
index 0000000..fba02ce
--- /dev/null
+++ b/tests/by-name/em/email-dns/nodes/user.nix
@@ -0,0 +1,70 @@
+{
+  pkgs,
+  vhackPackages,
+}: {
+  mkUser = user: serverName: {
+    nodes,
+    lib,
+    ...
+  }: {
+    imports = [
+      ../../../../common/acme/client.nix
+      ../../../../common/dns/client.nix
+    ];
+
+    environment.systemPackages = [
+      vhackPackages.fetchmail-common-name
+      pkgs.msmtp
+      pkgs.procmail
+
+      pkgs.bind
+      pkgs.openssl
+    ];
+
+    users.users."${user}" = {isNormalUser = true;};
+
+    systemd.tmpfiles.rules = [
+      "d /home/${user}/mail         0700 ${user} users - -"
+      "L /home/${user}/.fetchmailrc -    -       -     - /etc/homeSetup/.fetchmailrc"
+      "L /home/${user}/.procmailrc  -    -       -     - /etc/homeSetup/.procmailrc"
+      "L /home/${user}/.msmtprc     -    -       -     - /etc/homeSetup/.msmtprc"
+    ];
+
+    environment.etc = {
+      "homeSetup/.fetchmailrc" = {
+        text = ''
+          poll "${serverName}.server.com" protocol IMAP
+            username "${user}"
+            password "${user}-password"
+            ssl
+            mda procmail;
+        '';
+        mode = "0600";
+        inherit user;
+      };
+      "homeSetup/.procmailrc" = {
+        text = ''
+          DEFAULT=$HOME/mail
+        '';
+        mode = "0600";
+        inherit user;
+      };
+      "homeSetup/.msmtprc" = {
+        text = ''
+          account        ${user}
+          host           ${serverName}.server.com
+          domain         ${user}.com
+          port           465
+          from           ${user}@${user}.com
+          user           ${user}
+          password       ${user}-password
+          auth           on
+          tls            on
+          tls_starttls   off
+        '';
+        mode = "0600";
+        inherit user;
+      };
+    };
+  };
+}
diff --git a/tests/by-name/em/email-dns/test.nix b/tests/by-name/em/email-dns/test.nix
new file mode 100644
index 0000000..c7ba3b3
--- /dev/null
+++ b/tests/by-name/em/email-dns/test.nix
@@ -0,0 +1,167 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}: let
+  mail_server = import ./nodes/mail_server.nix {inherit extraModules pkgs vhackPackages;};
+  inherit (mail_server) mkMailServer;
+  user = import ./nodes/user.nix {inherit pkgs vhackPackages;};
+  inherit (user) mkUser;
+in
+  nixos-lib.runTest {
+    hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
+
+    name = "email-dns";
+
+    node = {
+      specialArgs = {inherit pkgsUnstable vhackPackages nixpkgs-unstable nixLib;};
+
+      # Use the nixpkgs as constructed by the `nixpkgs.*` options
+      pkgs = null;
+    };
+
+    nodes = {
+      acme = {
+        nodes,
+        lib,
+        ...
+      }: {
+        imports = [
+          ../../../common/acme/server.nix
+          ../../../common/dns/client.nix
+        ];
+      };
+
+      name_server = import ./nodes/name_server.nix {inherit extraModules;};
+
+      mail1_server =
+        mkMailServer "mail1"
+        {
+          class = "individual";
+          name = "bob";
+          secret = "{PLAIN}bob-password";
+          email = ["bob@bob.com"];
+        };
+
+      mail2_server =
+        mkMailServer "mail2"
+        {
+          class = "individual";
+          name = "alice";
+          secret = "{PLAIN}alice-password";
+          email = ["alice@alice.com"];
+        };
+
+      bob = mkUser "bob" "mail1";
+      alice = mkUser "alice" "mail2";
+    };
+
+    testScript = {...}: let
+      checkEmailEmpty = pkgs.writeShellScript "assert-empty-emails" ''
+        set -xe
+
+        # fetchmail returns EXIT_CODE 1 when no new mail
+        fetchmail --verbose >&2 || [ "$?" -eq 1 ] || {
+          echo "Mail was not empty" >&2
+          exit 1
+        }
+      '';
+      checkEmailNotEmpty = pkgs.writeShellScript "assert-empty-emails" ''
+        set -xe
+
+        # fetchmail returns EXIT_CODE 1 when no new mail
+        fetchmail --verbose >&2 || [ "$?" -ne 1 ] || {
+          echo "No new mail" >&2
+          exit 1
+        }
+      '';
+      checkSpamEmailNotEmpty = pkgs.writeShellScript "assert-empty-emails" ''
+        set -xe
+
+        # fetchmail returns EXIT_CODE 1 when no new mail
+        fetchmail --folder JUNK --verbose >&2 || [ "$?" -ne 1 ] || {
+          echo "No new mail" >&2
+          exit 1
+        }
+      '';
+
+      acme = import ../../../common/acme {inherit pkgs;};
+    in
+      acme.prepare ["mail1_server" "mail2_server" "alice" "bob"]
+      # Python
+      ''
+        from time import sleep
+
+        mail1_server.wait_for_unit("stalwart-mail.service")
+        mail1_server.wait_for_open_port(993) # imap
+        mail1_server.wait_for_open_port(465) # smtp
+        mail2_server.wait_for_unit("stalwart-mail.service")
+        mail2_server.wait_for_open_port(993) # imap
+        mail2_server.wait_for_open_port(465) # smtp
+
+        alice.wait_for_unit("multi-user.target")
+        bob.wait_for_unit("multi-user.target")
+
+        name_server.wait_until_succeeds("stat /var/lib/acme/mta-sts.alice.com/cert.pem")
+        name_server.wait_until_succeeds("stat /var/lib/acme/mta-sts.bob.com/cert.pem")
+
+        with subtest("Both mailserver successfully started all services"):
+          import json
+          def all_services_running(host):
+            (status, output) = host.systemctl("list-units --state=failed --plain --no-pager --output=json")
+            host_failed = json.loads(output)
+            assert len(host_failed) == 0, f"Expected zero failing services, but found: {json.dumps(host_failed, indent=4)}"
+          all_services_running(mail1_server)
+          all_services_running(mail2_server)
+
+        with subtest("Both start without mail"):
+          alice.succeed("sudo -u alice ${checkEmailEmpty}")
+          bob.succeed("sudo -u bob ${checkEmailEmpty}")
+
+        with subtest("Alice can send an empty email to bob"):
+          alice.succeed("sudo -u alice ${pkgs.writeShellScript "alice-send" ''
+          set -xe
+
+          echo "" | msmtp --debug --account alice bob@bob.com >&2
+        ''}")
+
+          # Give `mail2_server` some time to send the email.
+          sleep(160)
+
+          bob.succeed("sudo -u bob ${checkSpamEmailNotEmpty}")
+
+        with subtest("Alice can send an non-empty email to bob"):
+          alice.succeed("sudo -u alice ${pkgs.writeShellScript "alice-send" ''
+          set -xe
+
+          cat << EOF | msmtp --debug --account alice bob@bob.com >&2
+          Subject: Hi bob, I'm Alice!
+
+          Good day, Bob!
+
+          This is an email.
+          It contains a subject and a body.
+          I also assert utf8 support by including my last name in this very message.
+
+          XOXO
+          Alice van DÃ¥ligen.
+
+          .
+          EOF
+        ''}")
+
+          # Give `mail2_server` some time to send the email.
+          sleep(120)
+
+          bob.succeed("sudo -u bob ${checkEmailNotEmpty}")
+
+        mail1_server.copy_from_vm("/var/lib/", "server1")
+        mail2_server.copy_from_vm("/var/lib/", "server2")
+        bob.copy_from_vm("/home/bob/mail", "bob")
+      '';
+  }
diff --git a/tests/by-name/em/email-http/nodes/mail_server.nix b/tests/by-name/em/email-http/nodes/mail_server.nix
new file mode 100644
index 0000000..e94c4e9
--- /dev/null
+++ b/tests/by-name/em/email-http/nodes/mail_server.nix
@@ -0,0 +1,57 @@
+{
+  extraModules,
+  pkgs,
+  vhackPackages,
+}: {
+  mkMailServer = serverName: principal: {
+    config,
+    lib,
+    nodes,
+    ...
+  }: {
+    imports =
+      extraModules
+      ++ [
+        ../../../../../modules
+        ../../../../common/acme/client.nix
+      ];
+
+    environment.systemPackages = [
+      pkgs.bind
+      pkgs.openssl
+    ];
+
+    networking.nameservers = lib.mkForce [
+      nodes.name_server.networking.primaryIPAddress
+      nodes.name_server.networking.primaryIPv6Address
+    ];
+
+    age.identityPaths = ["${../../../../common/email/hostKey}"];
+
+    vhack = {
+      stalwart-mail = {
+        enable = true;
+        fqdn = "${serverName}.server.com";
+        admin = "admin@${serverName}.server.com";
+        security = {
+          dkimKeys = let
+            loadKey = name: {
+              dkimPublicKey = builtins.readFile (../../../../common/email/dkim + "/${name}/public");
+              dkimPrivateKeyPath = ../../../../common/email/dkim + "/${name}/private.age";
+              keyAlgorithm = "ed25519-sha256";
+            };
+          in {
+            "mail.server.com" = loadKey "mail1.server.com";
+            "bob.com" = loadKey "bob.com";
+          };
+          verificationMode = "strict";
+        };
+        openFirewall = true;
+        principals =
+          if principal == null
+          then null
+          else [principal];
+      };
+    };
+  };
+}
diff --git a/tests/by-name/em/email-http/nodes/user.nix b/tests/by-name/em/email-http/nodes/user.nix
new file mode 100644
index 0000000..73b9ff7
--- /dev/null
+++ b/tests/by-name/em/email-http/nodes/user.nix
@@ -0,0 +1,26 @@
+{
+  pkgs,
+  vhackPackages,
+}: {
+  mkUser = user: serverName: {
+    nodes,
+    lib,
+    ...
+  }: {
+    imports = [
+      ../../../../common/acme/client.nix
+    ];
+
+    environment.systemPackages = [
+      pkgs.bind
+      pkgs.openssl
+    ];
+
+    networking.nameservers = lib.mkForce [
+      nodes.name_server.networking.primaryIPAddress
+      nodes.name_server.networking.primaryIPv6Address
+    ];
+
+    users.users."${user}" = {isNormalUser = true;};
+  };
+}
diff --git a/tests/by-name/em/email-http/test.nix b/tests/by-name/em/email-http/test.nix
new file mode 100644
index 0000000..82b4c45
--- /dev/null
+++ b/tests/by-name/em/email-http/test.nix
@@ -0,0 +1,100 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}: let
+  mail_server = import ./nodes/mail_server.nix {inherit extraModules pkgs vhackPackages;};
+  inherit (mail_server) mkMailServer;
+  user = import ./nodes/user.nix {inherit pkgs vhackPackages;};
+  inherit (user) mkUser;
+in
+  nixos-lib.runTest {
+    hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
+
+    name = "email-http";
+
+    node = {
+      specialArgs = {inherit pkgsUnstable vhackPackages nixpkgs-unstable nixLib;};
+
+      # Use the nixpkgs as constructed by the `nixpkgs.*` options
+      pkgs = null;
+    };
+
+    nodes = {
+      acme = {
+        nodes,
+        lib,
+        ...
+      }: {
+        imports = [
+          ../../../common/acme/server.nix
+          ../../../common/dns/client.nix
+        ];
+      };
+
+      name_server = {nodes, ...}: {
+        imports =
+          extraModules
+          ++ [
+            ../../../common/acme/client.nix
+            ../../../common/dns/server.nix
+          ];
+
+        vhack.dns.zones = {
+          "mail.server.com" = {
+            SOA = {
+              nameServer = "ns";
+              adminEmail = "admin@server.com";
+              serial = 2025012301;
+            };
+            useOrigin = false;
+
+            A = [
+              nodes.mail_server.networking.primaryIPAddress
+            ];
+            AAAA = [
+              nodes.mail_server.networking.primaryIPv6Address
+            ];
+          };
+        };
+      };
+
+      mail_server = mkMailServer "mail" null;
+
+      bob = mkUser "bob" "mail";
+    };
+
+    # TODO(@bpeetz): This test should also test the http JMAP features of stalwart-mail. <2025-04-12>
+    testScript = _: let
+      acme = import ../../../common/acme {inherit pkgs;};
+    in
+      acme.prepare ["mail_server" "bob"]
+      # Python
+      ''
+        mail_server.wait_for_unit("stalwart-mail.service")
+        mail_server.wait_for_open_port(993) # imap
+        mail_server.wait_for_open_port(465) # smtp
+
+        bob.wait_for_unit("multi-user.target")
+
+        with subtest("The mailserver successfully started all services"):
+          import json
+          def all_services_running(host):
+            (status, output) = host.systemctl("list-units --state=failed --plain --no-pager --output=json")
+            host_failed = json.loads(output)
+            assert len(host_failed) == 0, f"Expected zero failing services, but found: {json.dumps(host_failed, indent=4)}"
+          all_services_running(mail_server)
+
+        with subtest("Bob can use the self-service interface"):
+          bob.succeed("${pkgs.writeShellScript "check-self-service" ''
+          curl mail.server.com --location --output /home/bob/output.html;
+        ''}")
+
+        bob.copy_from_vm("/home/bob", "")
+      '';
+  }
diff --git a/tests/by-name/em/email-ip/test.nix b/tests/by-name/em/email-ip/test.nix
new file mode 100644
index 0000000..dabc404
--- /dev/null
+++ b/tests/by-name/em/email-ip/test.nix
@@ -0,0 +1,174 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}: let
+  domain = "mail.server.test";
+
+  scripts = {
+    checkEmailEmpty = pkgs.writeShellScript "assert-empty-emails" ''
+      set -xe
+
+      # fetchmail returns EXIT_CODE 1 when no new mail
+      fetchmail --nosslcertck --verbose >&2 || [ "$?" -eq 1 ] || {
+        echo "Expected exit code 1." >&2
+        exit 1
+      }
+    '';
+  };
+
+  mkUser = user: {nodes, ...}: let
+    domainIp = nodes.server.networking.primaryIPAddress;
+  in {
+    environment.systemPackages = with pkgs; [
+      fetchmail
+      msmtp
+      procmail
+    ];
+
+    users.users."${user}" = {isNormalUser = true;};
+
+    systemd.tmpfiles.rules = [
+      "d /home/${user}/mail         0700 ${user} users - -"
+      "L /home/${user}/.fetchmailrc -    -       -     - /etc/homeSetup/.fetchmailrc"
+      "L /home/${user}/.procmailrc  -    -       -     - /etc/homeSetup/.procmailrc"
+      "L /home/${user}/.msmtprc     -    -       -     - /etc/homeSetup/.msmtprc"
+    ];
+
+    environment.etc = {
+      "homeSetup/.fetchmailrc" = {
+        text = ''
+          poll "${domainIp}" protocol IMAP
+            username "${user}"
+            password "${user}-password"
+            ssl
+            mda procmail;
+        '';
+        mode = "0600";
+        inherit user;
+      };
+      "homeSetup/.procmailrc" = {
+        text = ''
+          DEFAULT=$HOME/mail
+        '';
+        mode = "0600";
+        inherit user;
+      };
+      "homeSetup/.msmtprc" = {
+        text = ''
+          account        ${user}
+          host           ${domainIp}
+          port           465
+          from           ${user}@${domain}
+          user           ${user}
+          password       ${user}-password
+          auth           on
+          tls            on
+          tls_starttls   off
+        '';
+        mode = "0600";
+        inherit user;
+      };
+    };
+  };
+in
+  nixos-lib.runTest {
+    hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
+
+    name = "email";
+
+    node = {
+      specialArgs = {inherit pkgsUnstable vhackPackages nixpkgs-unstable nixLib;};
+
+      # Use the nixpkgs as constructed by the `nixpkgs.*` options
+      pkgs = null;
+    };
+
+    nodes = {
+      server = {config, ...}: {
+        imports =
+          extraModules
+          ++ [
+            ../../../../modules
+          ];
+
+        vhack = {
+          nginx = {
+            enable = true;
+            selfsign = true;
+          };
+
+          stalwart-mail = {
+            enable = true;
+            fqdn = domain;
+            admin = "mailto:admin@${domain}";
+            security = null;
+            openFirewall = true;
+            principals = [
+              {
+                class = "individual";
+                name = "alice";
+                secret = "{PLAIN}alice-password";
+                email = ["alice@${domain}"];
+              }
+              {
+                class = "individual";
+                name = "bob";
+                secret = "{PLAIN}bob-password";
+                email = ["bob@${domain}"];
+              }
+            ];
+          };
+        };
+      };
+
+      alice = mkUser "alice";
+      bob = mkUser "bob";
+    };
+
+    testScript = {...}:
+    /*
+    python
+    */
+    ''
+      start_all()
+
+      server.wait_for_unit("stalwart-mail.service")
+      server.wait_for_open_port(993) # imap
+      server.wait_for_open_port(465) # smtp
+
+      with subtest("Both start without mail"):
+        alice.succeed("sudo -u alice ${scripts.checkEmailEmpty}")
+        bob.succeed("sudo -u bob ${scripts.checkEmailEmpty}")
+
+      with subtest("Alice can send an email to bob"):
+        alice.succeed("sudo -u alice ${pkgs.writeShellScript "alice-send" ''
+        set -xe
+
+        cat << EOF | msmtp --debug --account alice --tls-certcheck=off bob@${domain} >&2
+        Hi Bob!
+
+        This is an email.
+        It contains a subject and a body.
+
+        ALICE
+        EOF
+      ''}")
+        bob.succeed("sudo -u bob ${pkgs.writeShellScript "bob-receive" ''
+        set -xe
+
+        fetchmail --nosslcertck --verbose >&2 || {
+          echo New Mail did not arrive
+          exit 1
+        }
+      ''}")
+
+      server.copy_from_vm("/var/lib/", "server")
+      bob.copy_from_vm("/home/bob/mail", "bob")
+    '';
+  }
diff --git a/tests/by-name/ru/rust-motd/test.nix b/tests/by-name/ru/rust-motd/test.nix
new file mode 100644
index 0000000..fef1df8
--- /dev/null
+++ b/tests/by-name/ru/rust-motd/test.nix
@@ -0,0 +1,62 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}:
+nixos-lib.runTest {
+  hostPkgs = pkgs;
+
+  name = "rust-motd";
+
+  node = {
+    specialArgs = {inherit pkgsUnstable extraModules vhackPackages nixpkgs-unstable nixLib;};
+
+    # Use the nixpkgs as constructed by the `nixpkgs.*` options
+    pkgs = null;
+  };
+
+  nodes = {
+    server = {config, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../../modules
+        ];
+
+      vhack = {
+        rust-motd.enable = true;
+      };
+    };
+  };
+
+  testScript = {nodes, ...}:
+  /*
+  python
+  */
+  ''
+    from time import sleep
+
+    start_all()
+
+    # Give the service time to run.
+    sleep(3)
+
+    with subtest("All services running"):
+      import json
+      def all_services_running(host):
+        (status, output) = host.systemctl("list-units --state=failed --plain --no-pager --output=json")
+        host_failed = json.loads(output)
+        assert len(host_failed) == 0, f"Expected zero failing services, but found: {json.dumps(host_failed, indent=4)}"
+      all_services_running(server)
+
+    with subtest("Motd generated"):
+      server.succeed("cat /var/lib/rust-motd/motd | tee /dev/stderr | grep --invert-match Error")
+
+    server.copy_from_vm("/var/lib/rust-motd/motd")
+  '';
+}
diff --git a/tests/by-name/sh/sharkey-cpu/test.nix b/tests/by-name/sh/sharkey-cpu/test.nix
new file mode 100644
index 0000000..438cfb3
--- /dev/null
+++ b/tests/by-name/sh/sharkey-cpu/test.nix
@@ -0,0 +1,81 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}:
+nixos-lib.runTest {
+  hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
+
+  name = "sharkey-cpu";
+
+  node = {
+    specialArgs = {inherit pkgsUnstable extraModules vhackPackages nixpkgs-unstable nixLib;};
+
+    # Use the nixpkgs as constructed by the `nixpkgs.*` options
+    pkgs = null;
+  };
+
+  nodes = {
+    server = {config, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../../modules
+        ];
+
+      vhack = {
+        persist.enable = true;
+        nginx.enable = true;
+        sharkey = {
+          enable = true;
+          fqdn = "sharkey.server";
+        };
+      };
+      systemd.services = {
+        # Avoid an error from this service.
+        "acme-sharkey.server".serviceConfig.ExecStart = pkgs.lib.mkForce "${pkgs.lib.getExe' pkgs.coreutils "true"}";
+
+        # Test that sharkey's hardening still allows access to the CPUs.
+        sharkey.serviceConfig.ExecStart = let
+          nodejs = pkgs.lib.getExe pkgsUnstable.nodejs;
+          script = pkgs.writeTextFile {
+            name = "script.js";
+            text = ''
+              import * as os from 'node:os';
+
+              console.log(os.cpus()[0].model)
+              console.log(os.cpus().length)
+            '';
+          };
+        in
+          pkgs.lib.mkForce "${nodejs} ${script}";
+      };
+    };
+  };
+
+  testScript = {nodes, ...}:
+  /*
+  python
+  */
+  ''
+    from time import sleep
+
+    start_all()
+
+    # Give the service time to run.
+    sleep(3)
+
+    with subtest("All services running"):
+      import json
+      def all_services_running(host):
+        (status, output) = host.systemctl("list-units --state=failed --plain --no-pager --output=json")
+        host_failed = json.loads(output)
+        assert len(host_failed) == 0, f"Expected zero failing services, but found: {json.dumps(host_failed, indent=4)}"
+      all_services_running(server)
+  '';
+}
diff --git a/tests/by-name/sh/sharkey/test.nix b/tests/by-name/sh/sharkey/test.nix
new file mode 100644
index 0000000..0d79cd2
--- /dev/null
+++ b/tests/by-name/sh/sharkey/test.nix
@@ -0,0 +1,102 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}:
+nixos-lib.runTest {
+  hostPkgs = pkgs; # the Nixpkgs package set used outside the VMs
+
+  name = "sharkey";
+
+  node = {
+    specialArgs = {inherit pkgsUnstable extraModules vhackPackages nixpkgs-unstable nixLib;};
+
+    # Use the nixpkgs as constructed by the `nixpkgs.*` options
+    pkgs = null;
+  };
+
+  nodes = {
+    acme = {...}: {
+      imports = [
+        ../../../common/acme/server.nix
+        ../../../common/dns/client.nix
+      ];
+    };
+    name_server = {nodes, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../common/acme/client.nix
+          ../../../common/dns/server.nix
+        ];
+
+      vhack.dns.zones = {
+        "sharkey.server" = {
+          SOA = {
+            nameServer = "ns";
+            adminEmail = "admin@server.com";
+            serial = 2025012301;
+          };
+          useOrigin = false;
+
+          A = [
+            nodes.server.networking.primaryIPAddress
+          ];
+          AAAA = [
+            nodes.server.networking.primaryIPv6Address
+          ];
+        };
+      };
+    };
+
+    server = {config, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../../modules
+          ../../../common/acme/client.nix
+          ../../../common/dns/client.nix
+        ];
+
+      vhack = {
+        persist.enable = true;
+        nginx.enable = true;
+        sharkey = {
+          enable = true;
+          fqdn = "sharkey.server";
+        };
+      };
+    };
+
+    client = {...}: {
+      imports = [
+        ../../../common/acme/client.nix
+        ../../../common/dns/client.nix
+      ];
+    };
+  };
+
+  testScript = {nodes, ...}: let
+    acme = import ../../../common/acme {inherit pkgs;};
+  in
+    acme.prepare ["server" "client"]
+    # Python
+    ''
+      server.wait_for_unit("sharkey.service")
+
+      with subtest("All services running"):
+        import json
+        def all_services_running(host):
+          (status, output) = host.systemctl("list-units --state=failed --plain --no-pager --output=json")
+          host_failed = json.loads(output)
+          assert len(host_failed) == 0, f"Expected zero failing services, but found: {json.dumps(host_failed, indent=4)}"
+        all_services_running(server)
+
+      client.wait_until_succeeds("curl --silent https://sharkey.server | grep 'Thank you for using Sharkey!'")
+    '';
+}
diff --git a/tests/by-name/ta/taskchampion-sync/test.nix b/tests/by-name/ta/taskchampion-sync/test.nix
new file mode 100644
index 0000000..cdbe062
--- /dev/null
+++ b/tests/by-name/ta/taskchampion-sync/test.nix
@@ -0,0 +1,151 @@
+{
+  nixos-lib,
+  pkgsUnstable,
+  nixpkgs-unstable,
+  vhackPackages,
+  pkgs,
+  extraModules,
+  nixLib,
+  ...
+}:
+nixos-lib.runTest {
+  hostPkgs = pkgs;
+  name = "taskchampion-sync";
+
+  node = {
+    specialArgs = {inherit pkgsUnstable vhackPackages nixpkgs-unstable nixLib;};
+
+    # Use the nixpkgs as constructed by the `nixpkgs.*` options
+    pkgs = null;
+  };
+
+  nodes = let
+    # The feature flag is only in version 3.2 and upwards. Stable is still on 3.1
+    taskwarriorPackage = pkgsUnstable.taskwarrior3.overrideAttrs (final: prev: {
+      cmakeFlags = (prev.cmakeFlags or []) ++ ["-DENABLE_TLS_NATIVE_ROOTS=true"];
+    });
+  in {
+    acme = {
+      imports = [
+        ../../../common/acme/server.nix
+        ../../../common/dns/client.nix
+      ];
+    };
+    name_server = {nodes, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../common/acme/client.nix
+          ../../../common/dns/server.nix
+        ];
+
+      vhack.dns.zones = {
+        "taskchampion.server" = {
+          SOA = {
+            nameServer = "ns";
+            adminEmail = "admin@server.com";
+            serial = 2025012301;
+          };
+          useOrigin = false;
+
+          A = [
+            nodes.server.networking.primaryIPAddress
+          ];
+          AAAA = [
+            nodes.server.networking.primaryIPv6Address
+          ];
+        };
+      };
+    };
+
+    server = {config, ...}: {
+      imports =
+        extraModules
+        ++ [
+          ../../../../modules
+          ../../../common/acme/client.nix
+          ../../../common/dns/client.nix
+        ];
+
+      vhack = {
+        persist.enable = true;
+        nginx.enable = true;
+        taskchampion-sync = {
+          enable = true;
+          fqdn = "taskchampion.server";
+        };
+      };
+    };
+
+    task_client1 = {config, ...}: {
+      imports = [
+        ../../../common/acme/client.nix
+        ../../../common/dns/client.nix
+      ];
+
+      environment.systemPackages = [
+        taskwarriorPackage
+      ];
+    };
+    task_client2 = {config, ...}: {
+      imports = [
+        ../../../common/acme/client.nix
+        ../../../common/dns/client.nix
+      ];
+
+      environment.systemPackages = [
+        taskwarriorPackage
+      ];
+    };
+  };
+
+  testScript = {nodes, ...}: let
+    # Generated with uuidgen
+    uuid = "bf01376e-04a4-435a-9263-608567531af3";
+    password = "nixos-test";
+
+    mkSyncConfig = path:
+      pkgs.writeShellScript "setup-config-file" ''
+        set -xe
+
+        mkdir --parents "$(dirname "${path}")"
+        echo 'sync.server.url=https://taskchampion.server' >> "${path}"
+        echo 'sync.server.client_id=${uuid}' >> "${path}"
+        echo 'sync.encryption_secret=${password}' >> "${path}"
+      '';
+
+    acme = import ../../../common/acme {inherit pkgs;};
+  in
+    acme.prepare ["server" "task_client1" "task_client2"]
+    # Python
+    ''
+      server.wait_for_unit("taskchampion-sync-server.service")
+      server.wait_for_open_port(443)
+
+      with subtest("Setup task syncing"):
+          for task in [task_client1, task_client2]:
+            # See man task-sync(5)
+            task.succeed("mkdir ~/.task")
+            task.succeed("${mkSyncConfig "$HOME/.taskrc"}")
+
+      with subtest("Can create tasks"):
+          task_client1.succeed("task add 'First task -- task_client1'")
+          task_client2.succeed("task add 'First task -- task_client2'")
+
+      # Wait for the server to acquire the acme certificate
+      task_client1.wait_until_succeeds("curl https://taskchampion.server")
+
+      with subtest("Can sync tasks"):
+          for task in [task_client1, task_client2]:
+            task.succeed("task sync")
+          task_client1.succeed("task sync")
+
+
+      with subtest("Have correct tasks"):
+          count1 = task_client1.succeed("task count")
+          count2 = task_client2.succeed("task count")
+
+          assert int(count1) == 2, f"We don't have exactly 2 tasks, but {count1}"
+          assert count1 == count2, f"The clients don't have the same amount of tasks, client1: {count1}, client2: {count2}"
+    '';
+}
diff --git a/tests/common/acme/certs/generate b/tests/common/acme/certs/generate
new file mode 100755
index 0000000..0d6258e
--- /dev/null
+++ b/tests/common/acme/certs/generate
@@ -0,0 +1,66 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -p gnutls -p dash -i dash --impure
+# shellcheck shell=dash
+
+# For development and testing.
+# Create a CA key and cert, and use that to generate a server key and cert.
+# Creates:
+#   ca.key.pem
+#   ca.cert.pem
+#   server.key.pem
+#   server.cert.pem
+
+export SEC_PARAM=ultra
+export EXPIRATION_DAYS=123456
+export ORGANIZATION="Vhack.eu Test Keys"
+export COUNTRY=EU
+export SAN="acme.test"
+export KEY_TYPE="ed25519"
+
+BASEDIR="$(dirname "$0")"
+GENERATION_LOCATION="$BASEDIR/output"
+cd "$BASEDIR" || {
+    echo "(BUG?) No basedir ('$BASEDIR')" 1>&2
+    exit 1
+}
+
+ca=false
+clients=false
+
+usage() {
+    echo "Usage: $0 --ca|--clients"
+    exit 2
+}
+
+if [ "$#" -eq 0 ]; then
+    usage
+fi
+
+for arg in "$@"; do
+    case "$arg" in
+    "--ca")
+        ca=true
+        ;;
+    "--clients")
+        clients=true
+        ;;
+    *)
+        usage
+        ;;
+    esac
+done
+
+[ -d "$GENERATION_LOCATION" ] || mkdir --parents "$GENERATION_LOCATION"
+cd "$GENERATION_LOCATION" || echo "(BUG?) No generation location fould!" 1>&2
+
+[ "$ca" = true ] && ../generate.ca
+
+# Creates:
+#   <client_name>.key.pem
+#   <client_name>.cert.pem
+#
+[ "$clients" = true ] && ../generate.client "acme.test"
+
+echo "(INFO) Look for the keys at: $GENERATION_LOCATION"
+
+# vim: ft=sh
diff --git a/tests/common/acme/certs/generate.ca b/tests/common/acme/certs/generate.ca
new file mode 100755
index 0000000..92832c5
--- /dev/null
+++ b/tests/common/acme/certs/generate.ca
@@ -0,0 +1,38 @@
+#! /usr/bin/env sh
+
+# Take the correct binary to create the certificates
+CERTTOOL=$(command -v gnutls-certtool 2>/dev/null || command -v certtool 2>/dev/null)
+if [ -z "$CERTTOOL" ]; then
+    echo "ERROR: No certtool found" >&2
+    exit 1
+fi
+
+# Create a CA key.
+$CERTTOOL \
+    --generate-privkey \
+    --sec-param "$SEC_PARAM" \
+    --key-type "$KEY_TYPE" \
+    --outfile ca.key.pem
+
+chmod 600 ca.key.pem
+
+# Sign a CA cert.
+cat <<EOF >ca.template
+country = $COUNTRY
+dns_name = "$SAN"
+expiration_days = $EXPIRATION_DAYS
+organization = $ORGANIZATION
+ca
+EOF
+#state = $STATE
+#locality = $LOCALITY
+
+$CERTTOOL \
+    --generate-self-signed \
+    --load-privkey ca.key.pem \
+    --template ca.template \
+    --outfile ca.cert.pem
+
+chmod 600 ca.cert.pem
+
+# vim: ft=sh
diff --git a/tests/common/acme/certs/generate.client b/tests/common/acme/certs/generate.client
new file mode 100755
index 0000000..5930298
--- /dev/null
+++ b/tests/common/acme/certs/generate.client
@@ -0,0 +1,44 @@
+#! /usr/bin/env sh
+
+# Take the correct binary to create the certificates
+CERTTOOL=$(command -v gnutls-certtool 2>/dev/null || command -v certtool 2>/dev/null)
+if [ -z "$CERTTOOL" ]; then
+    echo "ERROR: No certtool found" >&2
+    exit 1
+fi
+
+NAME=client
+if [ $# -gt 0 ]; then
+    NAME="$1"
+fi
+
+# Create a client key.
+$CERTTOOL \
+    --generate-privkey \
+    --sec-param "$SEC_PARAM" \
+    --key-type "$KEY_TYPE" \
+    --outfile "$NAME".key.pem
+
+chmod 600 "$NAME".key.pem
+
+# Sign a client cert with the key.
+cat <<EOF >"$NAME".template
+dns_name = "$NAME"
+dns_name = "$SAN"
+expiration_days = $EXPIRATION_DAYS
+organization = $ORGANIZATION
+encryption_key
+signing_key
+EOF
+
+$CERTTOOL \
+    --generate-certificate \
+    --load-privkey "$NAME".key.pem \
+    --load-ca-certificate ca.cert.pem \
+    --load-ca-privkey ca.key.pem \
+    --template "$NAME".template \
+    --outfile "$NAME".cert.pem
+
+chmod 600 "$NAME".cert.pem
+
+# vim: ft=sh
diff --git a/tests/common/acme/certs/output/acme.test.cert.pem b/tests/common/acme/certs/output/acme.test.cert.pem
new file mode 100644
index 0000000..687101d
--- /dev/null
+++ b/tests/common/acme/certs/output/acme.test.cert.pem
@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/common/acme/certs/output/acme.test.key.pem b/tests/common/acme/certs/output/acme.test.key.pem
new file mode 100644
index 0000000..06195b8
--- /dev/null
+++ b/tests/common/acme/certs/output/acme.test.key.pem
@@ -0,0 +1,25 @@
+Public Key Info:
+	Public Key Algorithm: EdDSA (Ed25519)
+	Key Security Level: High (256 bits)
+
+curve:	Ed25519
+private key:
+	9d:25:38:89:f2:37:d7:65:41:f5:24:ba:4c:19:fb:0f
+	86:c8:a3:cf:f7:08:57:69:cc:64:cf:55:2d:8e:99:3e
+	
+
+x:
+	76:2a:d9:c8:eb:7e:b9:6c:95:6c:6f:70:a8:ec:d9:c0
+	fb:4c:76:e9:9a:da:be:8d:ff:dd:96:b2:96:50:4a:3c
+	
+
+
+Public Key PIN:
+	pin-sha256:NPwZitkDv4isUmdiicSsM1t1OtYoxqhdvBUnqSc4bFQ=
+Public Key ID:
+	sha256:34fc198ad903bf88ac52676289c4ac335b753ad628c6a85dbc1527a927386c54
+	sha1:dff55324b48e70b72e8af23082f6ffa71db18041
+
+-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEIJ0lOInyN9dlQfUkukwZ+w+GyKPP9whXacxkz1Utjpk+
+-----END PRIVATE KEY-----
diff --git a/tests/common/acme/certs/output/acme.test.template b/tests/common/acme/certs/output/acme.test.template
new file mode 100644
index 0000000..320a170
--- /dev/null
+++ b/tests/common/acme/certs/output/acme.test.template
@@ -0,0 +1,5 @@
+dns_name = "acme.test"
+dns_name = "acme.test"
+expiration_days = 123456
+organization = Vhack.eu Test Keys
+encryption_key
diff --git a/tests/common/acme/certs/output/ca.cert.pem b/tests/common/acme/certs/output/ca.cert.pem
new file mode 100644
index 0000000..0fa9d14
--- /dev/null
+++ b/tests/common/acme/certs/output/ca.cert.pem
@@ -0,0 +1,10 @@
+-----BEGIN CERTIFICATE-----
+MIIBYDCCARKgAwIBAgIUdhVVcf+NgElqGuutU55FUDBtFVMwBQYDK2VwMCoxCzAJ
+BgNVBAYTAkVVMRswGQYDVQQKExJWaGFjay5ldSBUZXN0IEtleXMwIBcNMjUwMzAx
+MTEyNjU2WhgPMjM2MzAzMDYxMTI2NTZaMCoxCzAJBgNVBAYTAkVVMRswGQYDVQQK
+ExJWaGFjay5ldSBUZXN0IEtleXMwKjAFBgMrZXADIQCkO1LhHINvJjt41JD6UEc4
+ZKKUubB8lKPxSOyTkFBOgqNIMEYwDwYDVR0TAQH/BAUwAwEB/zAUBgNVHREEDTAL
+gglhY21lLnRlc3QwHQYDVR0OBBYEFLUZcL/zguHlulHg5GYyYhXmVt/6MAUGAytl
+cANBAFMFFy5tjuQtp5GVEN6qM50L4lteQuxfhlQqmOOfl06HV6153wJnrlKaTOYO
+t0dKlSqKROMYUYeU39xDp07MLAc=
+-----END CERTIFICATE-----
diff --git a/tests/common/acme/certs/output/ca.key.pem b/tests/common/acme/certs/output/ca.key.pem
new file mode 100644
index 0000000..64263bc
--- /dev/null
+++ b/tests/common/acme/certs/output/ca.key.pem
@@ -0,0 +1,25 @@
+Public Key Info:
+	Public Key Algorithm: EdDSA (Ed25519)
+	Key Security Level: High (256 bits)
+
+curve:	Ed25519
+private key:
+	82:0d:fc:f0:d6:82:89:63:e5:bc:23:78:ba:98:38:83
+	09:2d:e0:78:4c:53:92:e3:db:5b:2f:e4:39:ce:96:3d
+	
+
+x:
+	a4:3b:52:e1:1c:83:6f:26:3b:78:d4:90:fa:50:47:38
+	64:a2:94:b9:b0:7c:94:a3:f1:48:ec:93:90:50:4e:82
+	
+
+
+Public Key PIN:
+	pin-sha256:jpzYZMOHDPCeSXxfL+YUXgSPcbO9MAs8foGMP5CJiD8=
+Public Key ID:
+	sha256:8e9cd864c3870cf09e497c5f2fe6145e048f71b3bd300b3c7e818c3f9089883f
+	sha1:b51970bff382e1e5ba51e0e466326215e656dffa
+
+-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEIIIN/PDWgolj5bwjeLqYOIMJLeB4TFOS49tbL+Q5zpY9
+-----END PRIVATE KEY-----
diff --git a/tests/common/acme/certs/output/ca.template b/tests/common/acme/certs/output/ca.template
new file mode 100644
index 0000000..a2295d8
--- /dev/null
+++ b/tests/common/acme/certs/output/ca.template
@@ -0,0 +1,5 @@
+country = EU
+dns_name = "acme.test"
+expiration_days = 123456
+organization = Vhack.eu Test Keys
+ca
diff --git a/tests/common/acme/certs/snakeoil-certs.nix b/tests/common/acme/certs/snakeoil-certs.nix
new file mode 100644
index 0000000..aeb6dfc
--- /dev/null
+++ b/tests/common/acme/certs/snakeoil-certs.nix
@@ -0,0 +1,13 @@
+let
+  domain = "acme.test";
+in {
+  inherit domain;
+  ca = {
+    cert = ./output/ca.cert.pem;
+    key = ./output/ca.key.pem;
+  };
+  "${domain}" = {
+    cert = ./output/. + "/${domain}.cert.pem";
+    key = ./output/. + "/${domain}.key.pem";
+  };
+}
diff --git a/tests/common/acme/client.nix b/tests/common/acme/client.nix
new file mode 100644
index 0000000..2b870e8
--- /dev/null
+++ b/tests/common/acme/client.nix
@@ -0,0 +1,21 @@
+{
+  nodes,
+  lib,
+  ...
+}: let
+  inherit (nodes.acme.test-support.acme) caCert;
+  inherit (nodes.acme.test-support.acme) caDomain;
+in {
+  security = {
+    acme = {
+      acceptTerms = true;
+      defaults = {
+        server = "https://${caDomain}/dir";
+      };
+    };
+
+    pki = {
+      certificateFiles = lib.mkForce [caCert];
+    };
+  };
+}
diff --git a/tests/common/acme/default.nix b/tests/common/acme/default.nix
new file mode 100644
index 0000000..c756a4f
--- /dev/null
+++ b/tests/common/acme/default.nix
@@ -0,0 +1,47 @@
+{pkgs}: let
+  add_pebble_ca_certs = pkgs.writeShellScript "fetch-and-set-ca" ''
+    set -xe
+
+    # Fetch the randomly generated ca certificate
+    curl https://acme.test:15000/roots/0 > /tmp/ca.crt
+    curl https://acme.test:15000/intermediates/0 >> /tmp/ca.crt
+
+    # Append it to the various system stores
+    # The file paths are from <nixpgks>/modules/security/ca.nix
+    for cert_path in "ssl/certs/ca-certificates.crt" "ssl/certs/ca-bundle.crt" "pki/tls/certs/ca-bundle.crt"; do
+      cert_path="/etc/$cert_path"
+
+      mv "$cert_path" "$cert_path.old"
+      cat "$cert_path.old" > "$cert_path"
+      cat /tmp/ca.crt >> "$cert_path"
+    done
+
+    export NIX_SSL_CERT_FILE=/tmp/ca.crt
+    export SSL_CERT_FILE=/tmp/ca.crt
+
+    # TODO
+    # # P11-Kit trust source.
+    # environment.etc."ssl/trust-source".source = "$${cacertPackage.p11kit}/etc/ssl/trust-source";
+  '';
+in {
+  prepare = clients: extra:
+  # The parens are needed for the syntax highlighting to work.
+    ( # python
+      ''
+        # Start dependencies for the other services
+        acme.start()
+        acme.wait_for_unit("pebble.service")
+        name_server.start()
+        name_server.wait_for_unit("nsd.service")
+
+        # Start actual test
+        start_all()
+
+        with subtest("Add pebble ca key to all services"):
+          for node in [name_server, ${builtins.concatStringsSep "," clients}]:
+            node.wait_until_succeeds("curl https://acme.test:15000/roots/0")
+            node.succeed("${add_pebble_ca_certs}")
+      ''
+    )
+    + extra;
+}
diff --git a/tests/common/acme/server.nix b/tests/common/acme/server.nix
new file mode 100644
index 0000000..997c944
--- /dev/null
+++ b/tests/common/acme/server.nix
@@ -0,0 +1,91 @@
+# Add this node as acme server.
+# This also needs a DNS server.
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  testCerts = import ./certs/snakeoil-certs.nix;
+  inherit (testCerts) domain;
+
+  pebbleConf.pebble = {
+    listenAddress = "0.0.0.0:443";
+    managementListenAddress = "0.0.0.0:15000";
+
+    # The cert and key are used only for the Web Front End (WFE)
+    certificate = testCerts.${domain}.cert;
+    privateKey = testCerts.${domain}.key;
+
+    httpPort = 80;
+    tlsPort = 443;
+    ocspResponderURL = "http://${domain}:4002";
+    strict = true;
+  };
+
+  pebbleConfFile = pkgs.writeText "pebble.conf" (builtins.toJSON pebbleConf);
+in {
+  options.test-support.acme = {
+    caDomain = lib.mkOption {
+      type = lib.types.str;
+      default = domain;
+      readOnly = true;
+      description = ''
+        A domain name to use with the `nodes` attribute to
+        identify the CA server in the `client` config.
+      '';
+    };
+    caCert = lib.mkOption {
+      type = lib.types.path;
+      readOnly = true;
+      default = testCerts.ca.cert;
+      description = ''
+        A certificate file to use with the `nodes` attribute to
+        inject the test CA certificate used in the ACME server into
+        {option}`security.pki.certificateFiles`.
+      '';
+    };
+  };
+
+  config = {
+    networking = {
+      # This has priority 140, because modules/testing/test-instrumentation.nix
+      # already overrides this with priority 150.
+      nameservers = lib.mkOverride 140 ["127.0.0.1"];
+      firewall.allowedTCPPorts = [
+        80
+        443
+        15000
+        4002
+      ];
+
+      extraHosts = ''
+        127.0.0.1 ${domain}
+        ${config.networking.primaryIPAddress} ${domain}
+      '';
+    };
+
+    systemd.services = {
+      pebble = {
+        enable = true;
+        description = "Pebble ACME server";
+        wantedBy = ["network.target"];
+        environment = {
+          # We're not testing lego, we're just testing our configuration.
+          # No need to sleep.
+          PEBBLE_VA_NOSLEEP = "1";
+        };
+
+        serviceConfig = {
+          RuntimeDirectory = "pebble";
+          WorkingDirectory = "/run/pebble";
+
+          # Required to bind on privileged ports.
+          AmbientCapabilities = ["CAP_NET_BIND_SERVICE"];
+
+          ExecStart = "${pkgs.pebble}/bin/pebble -config ${pebbleConfFile}";
+        };
+      };
+    };
+  };
+}
diff --git a/tests/common/dns/client.nix b/tests/common/dns/client.nix
new file mode 100644
index 0000000..52f3267
--- /dev/null
+++ b/tests/common/dns/client.nix
@@ -0,0 +1,10 @@
+{
+  lib,
+  nodes,
+  ...
+}: {
+  networking.nameservers = lib.mkForce [
+    nodes.name_server.networking.primaryIPAddress
+    nodes.name_server.networking.primaryIPv6Address
+  ];
+}
diff --git a/tests/common/dns/server.nix b/tests/common/dns/server.nix
new file mode 100644
index 0000000..0c8d72c
--- /dev/null
+++ b/tests/common/dns/server.nix
@@ -0,0 +1,43 @@
+{
+  lib,
+  nodes,
+  ...
+}: {
+  imports = [
+    ../../../modules
+  ];
+
+  networking.nameservers = lib.mkForce [
+    nodes.name_server.networking.primaryIPAddress
+    nodes.name_server.networking.primaryIPv6Address
+  ];
+
+  vhack = {
+    dns = {
+      enable = true;
+      openFirewall = true;
+      interfaces = [
+        nodes.name_server.networking.primaryIPAddress
+        nodes.name_server.networking.primaryIPv6Address
+      ];
+
+      zones = {
+        "acme.test" = {
+          SOA = {
+            nameServer = "ns";
+            adminEmail = "admin@server.com";
+            serial = 2025012301;
+          };
+          useOrigin = false;
+
+          A = [
+            nodes.acme.networking.primaryIPAddress
+          ];
+          AAAA = [
+            nodes.acme.networking.primaryIPv6Address
+          ];
+        };
+      };
+    };
+  };
+}
diff --git a/tests/common/email/dkim/alice.com/private.age b/tests/common/email/dkim/alice.com/private.age
new file mode 100644
index 0000000..5415fdc
--- /dev/null
+++ b/tests/common/email/dkim/alice.com/private.age
@@ -0,0 +1,15 @@
+-----BEGIN AGE ENCRYPTED FILE-----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+-----END AGE ENCRYPTED FILE-----
diff --git a/tests/common/email/dkim/alice.com/public b/tests/common/email/dkim/alice.com/public
new file mode 100644
index 0000000..0f3c3b2
--- /dev/null
+++ b/tests/common/email/dkim/alice.com/public
@@ -0,0 +1 @@
+cLWzd3zg51ITME1Fnu16/h07lXIUxfhdLivktUMoVQs=
\ No newline at end of file
diff --git a/tests/common/email/dkim/bob.com/private.age b/tests/common/email/dkim/bob.com/private.age
new file mode 100644
index 0000000..c07c997
--- /dev/null
+++ b/tests/common/email/dkim/bob.com/private.age
@@ -0,0 +1,14 @@
+-----BEGIN AGE ENCRYPTED FILE-----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+-----END AGE ENCRYPTED FILE-----
diff --git a/tests/common/email/dkim/bob.com/public b/tests/common/email/dkim/bob.com/public
new file mode 100644
index 0000000..ddea670
--- /dev/null
+++ b/tests/common/email/dkim/bob.com/public
@@ -0,0 +1 @@
+3yrKD52yd5hBA6ue5uQVl7FXGK8UOlUE9Y+yCdBRfVQ=
\ No newline at end of file
diff --git a/tests/common/email/dkim/gen_key.sh b/tests/common/email/dkim/gen_key.sh
new file mode 100755
index 0000000..48b4434
--- /dev/null
+++ b/tests/common/email/dkim/gen_key.sh
@@ -0,0 +1,35 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -p rage -p openssl -p dash -i dash --impure
+
+# shellcheck shell=dash
+
+cd "$(dirname "$0")" || {
+    echo "No basedir?!"
+    exit 1
+}
+
+key_name="$1"
+[ -z "$key_name" ] && {
+    echo "Usage: $0 KEY_NAME"
+    exit 2
+}
+
+[ -d "$key_name" ] || mkdir "$key_name"
+cd "$key_name" || {
+    echo "Just created."
+    exit 1
+}
+
+openssl genpkey -algorithm ed25519 -out "private"
+openssl pkey -in "private" -pubout -out "public.tmp"
+
+openssl asn1parse -in "public.tmp" -offset 12 -noout -out /dev/stdout | base64 --wrap 0 >"public"
+rm "public.tmp"
+
+rage --encrypt \
+    --armor \
+    --recipient "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILxdvBk/PC9fC7B5vqe9TvygZKY6LgDQ2mXRdVrthBM/" \
+    "private" >"private.age"
+rm "private"
+
+# vim: ft=sh
diff --git a/tests/common/email/dkim/mail1.server.com/private.age b/tests/common/email/dkim/mail1.server.com/private.age
new file mode 100644
index 0000000..8c5d3c3
--- /dev/null
+++ b/tests/common/email/dkim/mail1.server.com/private.age
@@ -0,0 +1,15 @@
+-----BEGIN AGE ENCRYPTED FILE-----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-----END AGE ENCRYPTED FILE-----
diff --git a/tests/common/email/dkim/mail1.server.com/public b/tests/common/email/dkim/mail1.server.com/public
new file mode 100644
index 0000000..4941b85
--- /dev/null
+++ b/tests/common/email/dkim/mail1.server.com/public
@@ -0,0 +1 @@
+quDd9+ogqiIUWybfegosFFkG7jAsblij2VrkuUXEzzY=
\ No newline at end of file
diff --git a/tests/common/email/dkim/mail2.server.com/private.age b/tests/common/email/dkim/mail2.server.com/private.age
new file mode 100644
index 0000000..d39631a
--- /dev/null
+++ b/tests/common/email/dkim/mail2.server.com/private.age
@@ -0,0 +1,15 @@
+-----BEGIN AGE ENCRYPTED FILE-----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+-----END AGE ENCRYPTED FILE-----
diff --git a/tests/common/email/dkim/mail2.server.com/public b/tests/common/email/dkim/mail2.server.com/public
new file mode 100644
index 0000000..5c4406d
--- /dev/null
+++ b/tests/common/email/dkim/mail2.server.com/public
@@ -0,0 +1 @@
+th9exwaYvoAjxW1tAj3k/VNLl5jKzSC/dxKrxM2mTZE=
\ No newline at end of file
diff --git a/tests/common/email/hostKey b/tests/common/email/hostKey
new file mode 100644
index 0000000..79c9d6c
--- /dev/null
+++ b/tests/common/email/hostKey
@@ -0,0 +1,7 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
+QyNTUxOQAAACC8XbwZPzwvXwuweb6nvU78oGSmOi4A0Npl0XVa7YQTPwAAAJjFZPqHxWT6
+hwAAAAtzc2gtZWQyNTUxOQAAACC8XbwZPzwvXwuweb6nvU78oGSmOi4A0Npl0XVa7YQTPw
+AAAEA9D5AP+Uqhrg8rPx2DjgucjfnJknkk7lkeKHMV04ZZv7xdvBk/PC9fC7B5vqe9Tvyg
+ZKY6LgDQ2mXRdVrthBM/AAAAFSAnUHVibGljIHRlc3Rpbmcga2V5Jw==
+-----END OPENSSH PRIVATE KEY-----