1 files changed, 122 insertions, 0 deletions
diff --git a/modules/by-name/mo/monitoring/components/loki.nix b/modules/by-name/mo/monitoring/components/loki.nix
new file mode 100644
index 0000000..9a285c5
--- /dev/null
+++ b/modules/by-name/mo/monitoring/components/loki.nix
@@ -0,0 +1,122 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  cfg = config.vhack.monitoring.loki;
+in {
+  options.vhack.monitoring.loki = {
+    enable = lib.mkEnableOption "loki";
+
+    port = lib.mkOption {
+      type = lib.types.port;
+      description = "Port where Loki listens to HTTP requests.";
+      default = 3002;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    services = {
+      loki = {
+        enable = true;
+        dataDir = "/var/lib/loki";
+        package = pkgs.grafana-loki;
+        configuration = {
+          auth_enabled = false;
+
+          server.http_listen_port = cfg.port;
+
+          common = {
+            ring = {
+              instance_addr = "127.0.0.1";
+              kvstore = {
+                store = "inmemory";
+              };
+            };
+
+            replication_factor = 1;
+            path_prefix = "/tmp/loki";
+          };
+
+          schema_config = {
+            configs = [
+              {
+                from = "2020-05-15";
+                store = "tsdb";
+                object_store = "filesystem";
+                schema = "v13";
+                index = {
+                  prefix = "index_";
+                  period = "24h";
+                };
+              }
+            ];
+          };
+
+          storage_config = {
+            filesystem.directory = "/tmp/loki/chunks";
+          };
+        };
+      };
+
+      # I decided to switch to fluent-bit because it can be tested locally https://docs.fluentbit.io/manual/local-testing/logging-pipeline
+      fluent-bit = {
+        enable = true;
+        settings = {
+          service = {
+            flush = 1;
+            log_level = "info";
+            http_server = "true";
+            http_listen = "127.0.0.1";
+            http_port = 9080;
+            grace = 30;
+          };
+
+          pipeline = {
+            inputs = [
+              {
+                name = "systemd";
+
+                # The asterisk appends the _SYSTEMD_UNIT to the prefix.
+                tag = "systemd.*";
+
+                # Read logs from this systemd journal directory.
+                path = "/var/log/journal";
+
+                # Database file to keep track of the journald cursor.
+                db = "/var/fluent-bit/systemd.db";
+
+                # Start reading new entries. Skip entries already stored in journald.
+                read_from_tail = true;
+
+                # Max entries to lookback on start.
+                max_entries = 10000;
+              }
+            ];
+
+            outputs = [
+              {
+                name = "loki";
+
+                match = "systemd.*";
+
+                host = "localhost";
+                port = config.services.loki.configuration.server.http_listen_port;
+
+                labels = lib.concatMapAttrsStringSep ", " (n: v: "${n}=${v}") {
+                  job = "systemd-journal";
+                  inherit (config.vhack.monitoring.grafana) fqdn;
+                  hostname = config.networking.hostName;
+                };
+
+                label_keys = "$unit";
+              }
+            ];
+          };
+        };
+        graceLimit = "1m";
+      };
+    };
+  };
+}