feat: init loki

hosts/flora-6/apps/loki.nix

@@ -0,0 +1,76 @@
+{
+  config,
+  lib,
+  pkgs,
+  flake,
+  ...
+}: {
+  # source: https://gist.github.com/rickhull/895b0cb38fdd537c1078a858cf15d63e
+  # https://grafana.com/docs/loki/latest/configure/examples/#1-local-configuration-exampleyaml
+  services.loki = {
+    enable = true;
+    configuration = {
+      server.http_listen_port = 3100;
+      auth_enabled = false;
+      common = {
+        ring = {
+          instance_addr = "127.0.0.1";
+          kvstore = {
+            store = "inmemory";
+          };
+        };
+        replication_factor = 1;
+        path_prefix = "/var/lib/loki";
+        storage = {
+          filesystem = {
+            chunks_directory = "chunks/";
+            rules_directory = "rules/";
+          };
+        };
+      };
+
+      schema_config = {
+        configs = [{
+          from = "2020-05-15";
+          store = "boltdb-shipper";
+          object_store = "filesystem";
+          schema = "v11";
+          index = {
+            prefix = "index_";
+            period = "24h";
+          };
+        }];
+      };
+    };
+  };
+
+  services.promtail = {
+    enable = true;
+    configuration = {
+      server = {
+        http_listen_port = 9080;
+        grpc_listen_port = 0;
+      };
+      positions = {
+        filename = "/tmp/positions.yaml";
+      };
+      clients = [{
+        url = "http://127.0.0.1:${toString config.services.loki.configuration.server.http_listen_port}/loki/api/v1/push";
+      }];
+      scrape_configs = [{
+        job_name = "journal";
+        journal = {
+          max_age = "24h";
+          labels = {
+            job = "systemd-journal";
+            host = "flora-6";
+          };
+        };
+        relabel_configs = [{
+          source_labels = [ "__journal__systemd_unit" ];
+          target_label = "unit";
+        }];
+      }];
+    };
+  };
+}

hosts/flora-6/default.nix

@@ -13,5 +13,6 @@
       ./apps/forgejo-actions-runner.nix
       ./apps/grafana.nix
       ./apps/prometheus.nix
+      ./apps/loki.nix
     ];
 }