From 0e7a34a341110536ee912afdcaf2e79af2928b58 Mon Sep 17 00:00:00 2001
From: Petru Paler <petru@paler.net>
Date: Fri, 21 Jul 2023 06:31:05 +0100
Subject: [PATCH] Loki service configuration.

---
 hosts/common/nomad.nix |   1 +
 services/loki.hcl      | 118 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 119 insertions(+)
 create mode 100644 services/loki.hcl

diff --git a/hosts/common/nomad.nix b/hosts/common/nomad.nix
index 8cfd5f9..b619f0c 100644
--- a/hosts/common/nomad.nix
+++ b/hosts/common/nomad.nix
@@ -45,6 +45,7 @@ in
       allow_privileged = true;
       # for keepalived, though only really needing "NET_ADMIN","NET_BROADCAST","NET_RAW" on top of default
       allow_caps = ["all"];
+      volumes.enabled = true;
     };
   };
 
diff --git a/services/loki.hcl b/services/loki.hcl
new file mode 100644
index 0000000..3eac82f
--- /dev/null
+++ b/services/loki.hcl
@@ -0,0 +1,118 @@
+job "loki" {
+  datacenters = ["alo"]
+  type        = "service"
+  update {
+    max_parallel      = 1
+    health_check      = "checks"
+    min_healthy_time  = "10s"
+    healthy_deadline  = "3m"
+    progress_deadline = "5m"
+  }
+  group "loki" {
+    count = 1
+    restart {
+      attempts = 3
+      interval = "5m"
+      delay    = "25s"
+      mode     = "delay"
+    }
+    network {
+      port "loki" {
+        # static so that it can be hardcoded in the grafana data source
+        static = 3100
+      }
+    }
+    task "loki" {
+      driver = "docker"
+      config {
+        image = "grafana/loki:2.8.2"
+        args = [
+          "-config.file",
+          "local/loki/local-config.yaml",
+        ]
+        ports = ["loki"]
+        volumes = ["/data/compute/appdata/loki:/loki"]
+      }
+      template {
+        data = <<EOH
+auth_enabled: false
+server:
+  http_listen_port: 3100
+ingester:
+  lifecycler:
+    address: 127.0.0.1
+    ring:
+      kvstore:
+        store: inmemory
+      replication_factor: 1
+    final_sleep: 0s
+  # Any chunk not receiving new logs in this time will be flushed
+  chunk_idle_period: 1h
+  # All chunks will be flushed when they hit this age, default is 1h
+  max_chunk_age: 1h
+  # Loki will attempt to build chunks up to 1.5MB, flushing if chunk_idle_period or max_chunk_age is reached first
+  chunk_target_size: 1048576
+  # Must be greater than index read cache TTL if using an index cache (Default index read cache TTL is 5m)
+  chunk_retain_period: 30s
+  max_transfer_retries: 0     # Chunk transfers disabled
+  wal:
+    dir: "/tmp/wal"
+schema_config:
+  configs:
+    - from: 2023-01-01
+      store: boltdb-shipper
+      object_store: filesystem
+      schema: v11
+      index:
+        prefix: index_
+        period: 24h
+storage_config:
+  boltdb_shipper:
+    active_index_directory: /loki/boltdb-shipper-active
+    cache_location: /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: /loki/chunks
+compactor:
+  working_directory: /tmp/loki/boltdb-shipper-compactor
+  shared_store: filesystem
+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
+EOH
+        destination = "local/loki/local-config.yaml"
+      }
+      resources {
+        cpu    = 512
+        memory = 256
+      }
+      service {
+        name = "loki"
+        port = "loki"
+        check {
+          name     = "Loki healthcheck"
+          port     = "loki"
+          type     = "http"
+          path     = "/ready"
+          interval = "20s"
+          timeout  = "5s"
+          check_restart {
+            limit           = 3
+            grace           = "60s"
+            ignore_warnings = false
+          }
+        }
+        tags = [
+          "traefik.enable=true",
+          "traefik.http.routers.loki.entryPoints=websecure",
+        ]
+      }
+    }
+  }
+}