Add Loki and Promtail for beleth

hosts/x86_64-linux/beleth/config-files/loki-config.yaml

@@ -0,0 +1,48 @@
+auth_enabled: false
+
+server:
+  http_listen_port: 3100
+
+ingester:
+  lifecycler:
+    address: 0.0.0.0
+    ring:
+      kvstore:
+        store: inmemory
+      replication_factor: 1
+    final_sleep: 0s
+  chunk_idle_period: 1h       # Any chunk not receiving new logs in this time will be flushed
+  max_chunk_age: 1h           # All chunks will be flushed when they hit this age, default is 1h
+  chunk_target_size: 1048576  # Loki will attempt to build chunks up to 1.5MB, flushing first if chunk_idle_period or max_chunk_age is reached first
+  chunk_retain_period: 30s    # Must be greater than index read cache TTL if using an index cache (Default index read cache TTL is 5m)
+  max_transfer_retries: 0     # Chunk transfers disabled
+
+schema_config:
+  configs:
+    - from: 2020-10-24
+      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         # Can be increased for faster performance over longer query periods, uses more disk space
+    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

hosts/x86_64-linux/beleth/config-files/promtail.yaml

@@ -0,0 +1,21 @@
+server:
+  http_listen_port: 28183
+  grpc_listen_port: 0
+
+positions:
+  filename: /tmp/positions.yaml
+
+clients:
+  - url: http://127.0.0.1:3100/loki/api/v1/push
+
+scrape_configs:
+  - job_name: journal
+    journal:
+      max_age: 12h
+      labels:
+        job: systemd-journal
+        host: chrysalis
+    relabel_configs:
+      - source_labels: ["__journal__systemd_unit"]
+        target_label: "unit"
+

hosts/x86_64-linux/beleth/monitoring.nix

@@ -11,6 +11,22 @@
     domain = "grafana.heroin.trade";
   };
 
+  systemd.services.promtail = {
+    description = "Promtail service for Loki";
+    wantedBy = ["multi-user.target"];
+
+    serviceConfig = {
+      ExecStart = ''
+        ${pkgs.grafana-loki}/bin/promtail --config.file ${./config-files/promtail.yaml}
+      '';
+    };
+  };
+
+  services.loki = {
+    enable = true;
+    configFile = ./config-files/loki-config.yaml;
+  };
+
   services.prometheus = {
     enable = true;
     port = 9001;
@@ -31,7 +47,7 @@
           {
             targets = [
               "127.0.0.1:${toString config.services.prometheus.exporters.node.port}"
-              "127.0.0.1:${toString config.services.prometheus.exporters.wireguard.port}"
+              # "127.0.0.1:${toString config.services.prometheus.exporters.wireguard.port}"
             ];
           }
         ];