Bumping runner to Ubuntu 20.04 (#438)

Images for `actions-runner:v${VERSION}` and `actions-runner:latest` tags are upgraded to Ubuntu 20.04.

If you would like not to upgrade Ubuntu in the runner image in the future, migrate to new tags suffixed with `-ubuntu-20.04` like`actions-runner:v${VERSION}-ubuntu-20.04`.

We also keep publishing the existing Ubuntu 18.04 images with new `actions-runner:v${VERSION}-ubuntu-18.04` tags. Please use it when it turned out that you had workflows dependent on Ubuntu 18.04.

Co-authored-by: Yusuke Kuoka <ykuoka@gmail.com>

.github/workflows/build-and-release-runners.yml

@@ -13,7 +13,8 @@ on:
     paths:
       - runner/patched/*
       - runner/Dockerfile
-      - runner/dindrunner.Dockerfile
+      - runner/Dockerfile.ubuntu.1804
+      - runner/Dockerfile.dindrunner
       - runner/entrypoint.sh
       - .github/workflows/build-and-release-runners.yml
 
@@ -25,9 +26,14 @@ jobs:
       matrix:
         include:
           - name: actions-runner
+            os-version: 20.04
             dockerfile: Dockerfile
+          - name: actions-runner
+            os-version: 18.04
+            dockerfile: Dockerfile.ubuntu.1804
           - name: actions-runner-dind
-            dockerfile: dindrunner.Dockerfile
+            os-version: 20.04
+            dockerfile: Dockerfile.dindrunner
     env:
       RUNNER_VERSION: 2.277.1
       DOCKER_VERSION: 19.03.12
@@ -55,7 +61,7 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.DOCKER_ACCESS_TOKEN }}
 
-      - name: Build and Push
+      - name: Build and Push Versioned Tags
         uses: docker/build-push-action@v2
         with:
           context: ./runner
@@ -66,6 +72,18 @@ jobs:
             RUNNER_VERSION=${{ env.RUNNER_VERSION }}
             DOCKER_VERSION=${{ env.DOCKER_VERSION }}
           tags: |
-            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}
-            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-${{ steps.vars.outputs.sha_short }}
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-ubuntu-${{ matrix.os-version }}
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-ubuntu-${{ matrix.os-version }}-${{ steps.vars.outputs.sha_short }}
+
+      - name: Build and Push Latest Tag
+        uses: docker/build-push-action@v2
+        with:
+          context: ./runner
+          file: ./runner/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name != 'pull_request' }}
+          build-args: |
+            RUNNER_VERSION=${{ env.RUNNER_VERSION }}
+            DOCKER_VERSION=${{ env.DOCKER_VERSION }}
+          tags: |
             ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:latest