TUN-10612: Add renovate to cloudflared to update distroless images explicitely

Dockerfile.amd64

@@ -15,7 +15,7 @@ COPY . .
 RUN GOOS=linux GOARCH=amd64 make cloudflared
 
 # use a distroless base image with glibc
-FROM gcr.io/distroless/base-debian13:nonroot
+FROM gcr.io/distroless/base-debian13:nonroot-amd64@sha256:ced0a2b1936b14d5bddc2ee02a807b1586ca6576a967f5b043f4a3301c8a8f6b
 
 LABEL org.opencontainers.image.source="https://github.com/cloudflare/cloudflared"
 

Dockerfile.arm64

@@ -15,7 +15,7 @@ COPY . .
 RUN GOOS=linux GOARCH=arm64 make cloudflared
 
 # use a distroless base image with glibc
-FROM gcr.io/distroless/base-debian13:nonroot-arm64
+FROM gcr.io/distroless/base-debian13:nonroot-arm64@sha256:9c1ab6a3dbf9e22827b0be4a314d7cfbe008f922b7ca833ed0e5a63318c6169e
 
 LABEL org.opencontainers.image.source="https://github.com/cloudflare/cloudflared"
 

renovate.json

@@ -0,0 +1,36 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "config:recommended",
+    "schedule:nonOfficeHours"
+  ],
+  "enabledManagers": [
+    "dockerfile"
+  ],
+  "dockerfile": {
+    "managerFilePatterns": [
+      "/(^|/)Dockerfile\\.amd64$/",
+      "/(^|/)Dockerfile\\.arm64$/"
+    ]
+  },
+  "packageRules": [
+    {
+      "description": "Disable updates for everything by default; only the distroless base image is managed for now",
+      "matchPackageNames": [
+        "*"
+      ],
+      "enabled": false
+    },
+    {
+      "description": "Keep any distroless base image up to date by pinning and updating its digest, since tags like :nonroot are rolling tags without a semver version",
+      "matchManagers": [
+        "dockerfile"
+      ],
+      "matchPackageNames": [
+        "gcr.io/distroless/**"
+      ],
+      "enabled": true,
+      "pinDigests": true
+    }
+  ]
+}