GitHub: split git tag and image tag

This commit allows us to have different values for the git tag that is
checked out (RELEASE_VERSION) and the image tag that we push
(IMAGE_TAG).

Author: guggero

.github/workflows/docker.yml

@@ -30,16 +30,20 @@ jobs:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_API_KEY }}
 
+      # Make it possible to use different values for the version (used for git
+      # checkout) and the image tag (used for the docker image tag).
       - name: Set env
-        run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+        run: |
+          echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+          echo "IMAGE_TAG=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
 
       - name: Build and push default image
         id: docker_build
         uses: lightninglabs/gh-actions/[email protected]
         with:
           push: true
           platforms: linux/amd64,linux/arm64
-          tags: "${{ env.DOCKER_ORG }}/${{ env.DOCKER_REPO }}:${{ env.RELEASE_VERSION }}"
+          tags: "${{ env.DOCKER_ORG }}/${{ env.DOCKER_REPO }}:${{ env.IMAGE_TAG }}"
           build-args: checkout=${{ env.RELEASE_VERSION }}
 
       - name: Build and push image with /lit path
@@ -48,7 +52,7 @@ jobs:
         with:
           push: true
           platforms: linux/amd64,linux/arm64
-          tags: "${{ env.DOCKER_ORG }}/${{ env.DOCKER_REPO }}:${{ env.RELEASE_VERSION }}-path-prefix"
+          tags: "${{ env.DOCKER_ORG }}/${{ env.DOCKER_REPO }}:${{ env.IMAGE_TAG }}-path-prefix"
           build-args: |
             checkout=${{ env.RELEASE_VERSION }}
             public_url=/lit