viola: upstream

Signed-off-by: s0me1newithhand7s <git+me@hand7s.org>

viola/services/loki.nix

@@ -0,0 +1,127 @@
+{
+  pkgs,
+  lib,
+  ...
+}: {
+  services = {
+    loki = {
+      enable = true;
+
+      configuration = {
+        auth_enabled = false;
+        server = {
+          http_listen_port = 3100;
+          grpc_listen_port = 9097;
+        };
+
+        common = {
+          replication_factor = 1;
+          path_prefix = "/var/lib/loki";
+          ring = {
+            instance_addr = "127.0.0.1";
+            kvstore = {
+              store = "inmemory";
+            };
+          };
+        };
+
+        schema_config = {
+          configs = [
+            {
+              from = "2025-01-01";
+              store = "tsdb";
+              object_store = "filesystem";
+              schema = "v13";
+              index = {
+                prefix = "index_";
+                period = "24h";
+              };
+            }
+          ];
+        };
+
+        storage_config = {
+          filesystem = {
+            directory = "/var/lib/loki/chunks";
+          };
+        };
+
+        chunk_store_config = {
+          chunk_cache_config = {
+            redis = {
+              endpoint = "127.0.0.1:6385";
+              password = "loki";
+              db = 0;
+              timeout = "500ms";
+              expiration = "24h";
+            };
+          };
+        };
+
+        compactor = {
+          working_directory = "/var/lib/loki/compactor";
+          retention_enabled = true;
+          delete_request_store = "filesystem";
+        };
+
+        limits_config = {
+          reject_old_samples = true;
+          reject_old_samples_max_age = "168h";
+          retention_period = "720h";
+        };
+
+        query_range = {
+          cache_results = true;
+          results_cache = {
+            cache = {
+              redis = {
+                endpoint = "127.0.0.1:6385";
+                password = "loki";
+                db = 0;
+                timeout = "500ms";
+                expiration = "1h";
+              };
+            };
+          };
+        };
+
+        ruler = {
+          enable_api = true;
+          alertmanager_url = "http://127.0.0.1:9093";
+          storage = {
+            type = "local";
+            local = {
+              directory = "${pkgs.writeTextDir "fake/homelab.yaml" (lib.generators.toYAML {} {
+                groups = [
+                  {
+                    name = "homelab";
+                    interval = "1m";
+                    rules = [
+                      {
+                        alert = "HostDown";
+                        expr = ''absent_over_time({host="viola"}[10m])'';
+                        for = "10m";
+                        labels = {severity = "critical";};
+                        annotations = {
+                          summary = "Host viola not sending logs";
+                        };
+                      }
+                      {
+                        alert = "OOMKiller";
+                        expr = ''count_over_time({host="viola"} |= "Out of memory: Killed process" [5m]) > 0'';
+                        labels = {severity = "warning";};
+                        annotations = {
+                          summary = "OOM killer fired on viola";
+                        };
+                      }
+                    ];
+                  }
+                ];
+              })}";
+            };
+          };
+        };
+      };
+    };
+  };
+}