Use loki in k3d agent DS instead of promtail (#406)

CHANGELOG.md

@@ -10,6 +10,9 @@ can be found at [#317](https://github.com/grafana/agent/issues/317).
   longer report an error and will instead use the pre-existing default value.
   (@rfratto)
 
+- [BUGFIX] Fixed a bug from v0.12.0 where the Loki installation script failed
+  because positions_directory was not set. (@rfratto)
+
 # v0.12.0 (2021-02-05)
 
 BREAKING CHANGES: This release has two breaking changes in the configuration

example/k3d/environment/main.jsonnet

@@ -4,6 +4,7 @@ local agent_cluster = import 'grafana-agent/scraping-svc/main.libsonnet';
 local k = import 'ksonnet-util/kausal.libsonnet';
 
 local grafana_agent = import 'grafana-agent/v1/main.libsonnet';
+local loki_config = import 'default/loki_config.libsonnet';
 
 local service = k.core.v1.service;
 local images = {
@@ -51,7 +52,13 @@ local images = {
     }) +
     grafana_agent.withRemoteWrite([{
       url: 'http://cortex.default.svc.cluster.local/api/prom/push',
-    }]),
+    }]) +
+    grafana_agent.withLokiConfig(loki_config) +
+    grafana_agent.withLokiClients(grafana_agent.newLokiClient({
+      scheme: 'http',
+      hostname: 'loki.default.svc.cluster.local',
+      external_labels: { cluster: cluster_label },
+    })),
 
   // Need to run ETCD for agent_cluster
   etcd: etcd.new('default'),

example/k3d/jsonnetfile.json

@@ -19,15 +19,6 @@
       },
       "version": "master"
     },
-    {
-      "source": {
-        "git": {
-          "remote": "https://github.com/grafana/loki",
-          "subdir": "production/ksonnet/promtail"
-        }
-      },
-      "version": "master"
-    },
     {
       "source": {
         "git": {

example/k3d/jsonnetfile.lock.json

@@ -51,16 +51,6 @@
       "version": "b9cc0f3529833096c043084c04bc7b3562a134c4",
       "sum": "mtTAh8vSa4Eb8ojviyZ9zE2pPq5OgwhK75qsEWkifhI="
     },
-    {
-      "source": {
-        "git": {
-          "remote": "https://github.com/grafana/loki.git",
-          "subdir": "production/ksonnet/promtail"
-        }
-      },
-      "version": "10a1f28a85b5506c662688611442d31867fe2bc0",
-      "sum": "MOoAhHzLkR7NSqD7ZVqjlcSDNRUz3fVgJQiYM1hd+us="
-    },
     {
       "source": {
         "git": {

example/k3d/lib/default/loki_config.libsonnet

@@ -0,0 +1,41 @@
+local grafana_agent = import 'grafana-agent/v1/main.libsonnet';
+
+grafana_agent.scrapeKubernetesLogs {
+  local pipeline_stages = [
+    // k3d uses cri for logging
+    { cri: {} },
+
+    // Bad words metrics, used in Agent dashboard
+    {
+      regex: {
+        expression: '(?i)(?P<bad_words>panic:|core_dumped|failure|error|attack| bad |illegal |denied|refused|unauthorized|fatal|failed|Segmentation Fault|Corrupted)',
+      },
+    },
+    {
+      metrics: {
+        panic_total: {
+          type: 'Counter',
+          description: 'total count of panic: found in log lines',
+          source: 'panic',
+          config: {
+            action: 'inc',
+          },
+        },
+        bad_words_total: {
+          type: 'Counter',
+          description: 'total count of bad words found in log lines',
+          source: 'bad_words',
+          config: {
+            action: 'inc',
+          },
+        },
+      },
+    },
+  ],
+
+  scrape_configs: [
+    x { pipeline_stages: pipeline_stages }
+    for x
+    in super.scrape_configs
+  ],
+}

example/k3d/lib/default/main.libsonnet

@@ -4,7 +4,6 @@ local grafana = import 'grafana/main.libsonnet';
 local k = import 'ksonnet-util/kausal.libsonnet';
 local loki = import 'loki/main.libsonnet';
 local metrics = import 'metrics-server/main.libsonnet';
-local promtail = import 'promtail/promtail.libsonnet';
 
 local mixins = import './mixins.libsonnet';
 
@@ -22,51 +21,6 @@ local mixins = import './mixins.libsonnet';
 
     loki: loki.new(namespace),
 
-    promtail: promtail {
-      _config+:: {
-        namespace: namespace,
-        promtail_config+: {
-          clients: [{
-            scheme:: 'http',
-            hostname:: 'loki.default.svc.cluster.local',
-            external_labels: {},
-          }],
-
-          pipeline_stages: [
-            // k3d uses cri for logging
-            { cri: {} },
-
-            // Bad words metrics, used in Agent dashboard
-            {
-              regex: {
-                expression: '(?i)(?P<bad_words>panic:|core_dumped|failure|error|attack| bad |illegal |denied|refused|unauthorized|fatal|failed|Segmentation Fault|Corrupted)',
-              },
-            },
-            {
-              metrics: {
-                panic_total: {
-                  type: 'Counter',
-                  description: 'total count of panic: found in log lines',
-                  source: 'panic',
-                  config: {
-                    action: 'inc',
-                  },
-                },
-                bad_words_total: {
-                  type: 'Counter',
-                  description: 'total count of bad words found in log lines',
-                  source: 'bad_words',
-                  config: {
-                    action: 'inc',
-                  },
-                },
-              },
-            },
-          ],
-        },
-      },
-    },
-
     cortex: cortex.new(namespace),
   },
 }

example/k3d/scripts/create.bash

@@ -4,4 +4,5 @@ k3d create \
   --name agent-k3d \
   --publish 30080:30080 \
   --api-port 50443 \
-  -v /var/lib/k3d/agent-k3d/storage/:/var/lib/rancher/k3s/storage/
+  -v /var/lib/k3d/agent-k3d/storage/:/var/lib/rancher/k3s/storage/ \
+  -v /etc/machine-id:/etc/machine-id