Configure the github release action for private go modules (#12)

* Configure the github release action for private go modules

- cluster-controller (private repo) was introduced as a go dep and we
  need to do the classic git hacks to allow go mod to read the new
  private repo dependency

* Configure docker host's git for private go modules too

.github/workflows/release.yaml

@@ -2,6 +2,9 @@ on:
   push:
     tags: [v*.*.*]
 
+env:
+  GOPRIVATE: github.com/weaveworks/cluster-controller
+
 name: release
 jobs:
   build:
@@ -16,7 +19,15 @@ jobs:
       with:
         fetch-depth: 0
         ref: ${{ github.event.pull_request.head.sha }}
+    - name: Configure git for private modules
+      env:
+        GITHUB_BUILD_USERNAME: ${{ secrets.BUILD_BOT_USER }}
+        GITHUB_BUILD_TOKEN: ${{ secrets.BUILD_BOT_PERSONAL_ACCESS_TOKEN }}
+      run: git config --global url."https://${GITHUB_BUILD_USERNAME}:${GITHUB_BUILD_TOKEN}@github.com".insteadOf "https://github.com"
     - name: Build docker image
+      env:
+        GITHUB_BUILD_USERNAME: ${{ secrets.BUILD_BOT_USER }}
+        GITHUB_BUILD_TOKEN: ${{ secrets.BUILD_BOT_PERSONAL_ACCESS_TOKEN }}
       run: |
         make docker-build
     - name: Login to Docker Hub