monitoring: Add Loki + promtail

modules/monitoring/monitoring.nix

@@ -36,6 +36,108 @@ in
       };
     };
 
+    loki = {
+      enable = true;
+      configuration = {
+        server.http_listen_port = 3030;
+        auth_enabled = false;
+
+        ingester = {
+          lifecycler = {
+            address = "127.0.0.1";
+            ring = {
+              kvstore.store = "inmemory";
+              replication_factor = 1;
+            };
+          };
+          chunk_idle_period = "1h";
+          max_chunk_age = "1h";
+          chunk_target_size = 999999;
+          chunk_retain_period = "30s";
+          max_transfer_retries = 0;
+        };
+        schema_config = {
+          configs = [{
+            from = "2022-06-06";
+            store = "boltdb-shipper";
+            object_store = "filesystem";
+            schema = "v11";
+            index = {
+              prefix = "index_";
+              period = "24h";
+            };
+          }];
+        };
+
+        storage_config = {
+          boltdb_shipper = {
+            active_index_directory = "/var/lib/loki/boltdb-shipper-active";
+            cache_location = "/var/lib/loki/boltdb-shipper-cache";
+            cache_ttl = "24h";
+            shared_store = "filesystem";
+          };
+
+          filesystem = {
+            directory = "/var/lib/loki/chunks";
+          };
+        };
+
+        limits_config = {
+          reject_old_samples = true;
+          reject_old_samples_max_age = "168h";
+        };
+
+        chunk_store_config = {
+          max_look_back_period = "0s";
+        };
+
+        table_manager = {
+          retention_deletes_enabled = false;
+          retention_period = "0s";
+        };
+
+        compactor = {
+          working_directory = "/var/lib/loki";
+          shared_store = "filesystem";
+          compactor_ring = {
+            kvstore = {
+              store = "inmemory";
+            };
+          };
+        };
+      };
+    };
+
+    promtail = {
+      enable = true;
+      configuration = {
+        server = {
+          http_listen_port = 3031;
+          grpc_listen_port = 0;
+        };
+        positions = {
+          filename = "/tmp/positions.yaml";
+        };
+        clients = [{
+          url = "http://127.0.0.1:${toString config.services.loki.configuration.server.http_listen_port}/loki/api/v1/push";
+        }];
+        scrape_configs = [{
+          job_name = "journal";
+          journal = {
+            max_age = "12h";
+            labels = {
+              job = "systemd-journal";
+              host = "pihole";
+            };
+          };
+          relabel_configs = [{
+            source_labels = [ "__journal__systemd_unit" ];
+            target_label = "unit";
+          }];
+        }];
+      };
+    };
+
     # Show data with fancy graphs
     grafana = {
       enable = true;
@@ -48,6 +150,12 @@ in
             access = "proxy";
             url = "http://127.0.0.1:8428";
           }
+          {
+            name = "Loki";
+            type = "loki";
+            access = "proxy";
+            url = "http://127.0.0.1:${toString config.services.loki.configuration.server.http_listen_port}";
+          }
         ];
       };
       settings = {