renovate: Add automatic version upgrades for docker containers

This is the renovate config, to allow renovate to check ansible variables with docker container tags.

This configuration was taken from Sheogoraths Infrastructure repository: 6c1dc180d4/.renovaterc.json

Thank you <3

.renovaterc.json

@@ -0,0 +1,38 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "config:base",
+    "docker:enableMajor"
+  ],
+  "prConcurrentLimit": 5,
+  "semanticCommits": false,
+  "commitMessagePrefix": "automation:",
+  "commitMessageTopic": "{{depName}}",
+  "commitMessageExtra": "to {{#if isMajor}}version {{{newMajor}}}{{else}}{{#if isSingleVersion}}version {{{toVersion}}}{{else}}{{{newValue}}}{{/if}}{{/if}}",
+  "regexManagers": [
+  {
+      "fileMatch": ["defaults/main.yml$"],
+      "matchStrings": [
+        "# renovate: depName=(?<lookupName>.*?)( versioning=(?<versioning>.*?))?\\n(?<roleName>\\S+?)(_(?<softwareName>\\S+?))?_version: \"?(?<currentValue>[^\"]*?)\"?\\s"
+      ],
+      "depNameTemplate": "{{#if softwareName}}{{{roleName}}}-{{{softwareName}}}{{else}}{{{roleName}}}{{/if}}",
+      "datasourceTemplate": "docker",
+      "versioningTemplate": "{{#if versioning}}{{{versioning}}}{{else}}docker{{/if}}"
+    }
+  ],
+  "docker": {
+    "commitMessageTopic": "{{{depName}}}",
+    "commitMessageExtra": "to {{#if isMajor}}version {{{newMajor}}}{{else}}{{#if isSingleVersion}}version {{{toVersion}}}{{else}}{{{newValue}}}{{/if}}{{/if}}"
+  },
+  "packageRules": [
+    {
+      "packageNames": [
+        "docker.io/cactus4docker/go-camo",
+        "docker.io/tootsuite/mastodon",
+        "docker.io/ldez/traefik-certs-dumper",
+        "docker.io/matrixdotorg/synapse"
+      ],
+      "extractVersion": "^v(?<version>.*)$"
+    }
+  ]
+}