ci/renovate: split configuration

.github/renovate-selfhosted.json

@@ -0,0 +1,7 @@
+{
+  "username": "GrafanaRenovateBot",
+  "platform": "github",
+  "repositories": [
+    "grafana/synthetic-monitoring-agent"
+  ]
+}

.github/renovate.json → .github/renovate.json5

@@ -6,19 +6,15 @@
   ],
 
   "branchPrefix": "grafanarenovatebot/",
-  "username": "GrafanaRenovateBot",
   "gitAuthor": "GrafanaRenovateBot <[email protected]>",
+  // Used when renovate runs as a github app.
+  // https://docs.renovatebot.com/configuration-options/#platformcommit
   "platformCommit": true,
   "dependencyDashboard": false,
-  "platform": "github",
   "forkProcessing": "disabled",
 
-  "repositories": [
-    "grafana/synthetic-monitoring-agent"
-  ],
-
+  // TODO: We should be able to use the defaults if we turn dependabot off.
   "enabledManagers": ["custom.regex", "gomod"],
-
   "gomod": {
     "enabled": true
   },
@@ -29,6 +25,7 @@
 
   "customManagers": [
     {
+      // Update k6 version in Dockerfiles.
       "customType": "regex",
       "datasourceTemplate": "github-releases",
       "depNameTemplate": "grafana/k6",
@@ -38,6 +35,7 @@
       ]
     },
     {
+      // Update grafana-build-tools tags across the repository.
       "customType": "regex",
       "datasourceTemplate": "github-tags",
       "versioningTemplate": "semver",

.github/workflows/renovate.yaml

@@ -23,5 +23,5 @@ jobs:
         uses: renovatebot/github-action@21d88b0bf0183abcee15f990011cca090dfc47dd # v40.1.12
         with:
           renovate-version: 37.420.1@sha256:528f003c9aa77f6e916e3f9f5cc2fb9ae16fcf285af66f412a34325124f4a00e
-          configurationFile: .github/renovate.json
+          configurationFile: .github/renovate-selfhosted.json
           token: '${{ steps.generate-token.outputs.token }}'