feat(*): initialize new Snix infrastructure

Co-Authored-By: edef <edef@edef.eu>
Co-Authored-by: Ryan Lahfa <raito@lix.systems>
Change-Id: Ica1cda177a236814de900f50a8a61d288f58f519

ops/modules/o11y/loki.nix

@@ -0,0 +1,90 @@
+{ config
+, lib
+, ...
+}:
+let
+  cfg = config.services.depot.loki;
+  inherit (lib) mkEnableOption mkIf;
+in
+{
+  options.services.depot.loki.enable = mkEnableOption "Loki storage";
+
+  config = mkIf cfg.enable {
+    services.loki = {
+      enable = true;
+      extraFlags = [ "--config.expand-env" ];
+
+      configuration = {
+        server = {
+          http_listen_port = 9090;
+          grpc_listen_port = 9096;
+
+          # 16M
+          grpc_server_max_recv_msg_size = 16777216;
+          grpc_server_max_send_msg_size = 16777216;
+        };
+
+        auth_enabled = false;
+
+        common = {
+          storage.s3 = {
+            endpoint = "fsn1.your-objectstorage.com";
+            region = "fsn1";
+            bucketnames = "snix-loki";
+            secret_access_key = "\${S3_KEY}"; # This is a secret injected via an environment variable
+            access_key_id = "\${S3_KEY_ID}";
+            s3forcepathstyle = true;
+          };
+          ring = {
+            kvstore.store = "memberlist";
+            # TODO: Such a ugly hack.
+            instance_interface_names = [ "enp1s0" "lo" ];
+          };
+          replication_factor = 1;
+        };
+
+        memberlist = {
+          advertise_addr = "127.0.0.1";
+          cluster_label = "snix";
+          bind_port = 7947;
+          advertise_port = 7947;
+        };
+
+        storage_config.tsdb_shipper = {
+          active_index_directory = "/var/lib/loki/index";
+          cache_location = "/var/lib/loki/cache";
+        };
+
+        compactor = {
+          working_directory = "/var/lib/loki/compactor";
+          compaction_interval = "10m";
+          retention_enabled = true;
+          retention_delete_delay = "1s";
+          retention_delete_worker_count = 150;
+          delete_request_store = "filesystem";
+        };
+
+        limits_config.retention_period = "1w";
+
+        schema_config = {
+          configs = [
+            {
+              from = "2024-07-01";
+              store = "tsdb";
+              object_store = "s3";
+              schema = "v13";
+              index = {
+                prefix = "index_";
+                period = "24h";
+              };
+            }
+          ];
+        };
+      };
+    };
+
+    systemd.services.loki.serviceConfig.EnvironmentFile = [ config.age.secrets.loki-environment.path ];
+
+    infra.monitoring.grafana-agent.exporters.loki.port = 9090;
+  };
+}