Revert docker.sock path to /var/run/docker.sock (#2536)

Starting ARC v0.27.2, we've changed the `docker.sock` path from `/var/run/docker.sock` to `/var/run/docker/docker.sock`. That resulted in breaking some container-based actions due to the hard-coded `docker.sock` path in various places.

Even `actions/runner` seem to use `/var/run/docker.sock` for building container-based actions and for service containers?

Anyway, this fixes that by moving the sock file back to the previous location.

Once this gets merged, users stuck at ARC v0.27.1, previously upgraded to 0.27.2 or 0.27.3 and reverted back to v0.27.1 due to #2519, should be able to upgrade to the upcoming v0.27.4.

Resolves #2519
Resolves #2538

acceptance/deploy.sh

@@ -102,6 +102,7 @@ if [ "${tool}" == "helm" ]; then
     --set githubWebhookServer.podAnnotations.test-id=${TEST_ID} \
     --set actionsMetricsServer.podAnnotations.test-id=${TEST_ID} \
     ${flags[@]} --set image.imagePullPolicy=${IMAGE_PULL_POLICY} \
+    --set image.dindSidecarRepositoryAndTag=${DIND_SIDECAR_REPOSITORY_AND_TAG} \
     -f ${VALUES_FILE}
   set +v
   # To prevent `CustomResourceDefinition.apiextensions.k8s.io "runners.actions.summerwind.dev" is invalid: metadata.annotations: Too long: must have at most 262144 bytes`

acceptance/deploy_runners.sh

@@ -6,6 +6,10 @@ OP=${OP:-apply}
 
 RUNNER_LABEL=${RUNNER_LABEL:-self-hosted}
 
+# See https://github.com/actions/actions-runner-controller/issues/2123
+kubectl delete secret generic docker-config || :
+kubectl create secret generic docker-config --from-file .dockerconfigjson=<(jq -M 'del(.aliases)' $HOME/.docker/config.json) --type=kubernetes.io/dockerconfigjson || :
+
 cat acceptance/testdata/kubernetes_container_mode.envsubst.yaml  | NAMESPACE=${RUNNER_NAMESPACE} envsubst  | kubectl apply -f -
 
 if [ -n "${TEST_REPO}" ]; then

acceptance/testdata/runnerdeploy.envsubst.yaml

@@ -95,6 +95,24 @@ spec:
         # that part is created by dockerd.
         mountPath: /home/runner/.local
         readOnly: false
+      # See https://github.com/actions/actions-runner-controller/issues/2123
+      # Be sure to omit the "aliases" field from the config.json.
+      # Otherwise you may encounter nasty errors like:
+      #   $ docker build
+      #   docker: 'buildx' is not a docker command.
+      #   See 'docker --help'
+      # due to the incompatibility between your host docker config.json and the runner environment.
+      # That is, your host dockcer config.json might contain this:
+      #   "aliases": {
+      #     "builder": "buildx"
+      #   }
+      # And this results in the above error when the runner does not have buildx installed yet.
+      - name: docker-config
+        mountPath: /home/runner/.docker/config.json
+        subPath: config.json
+        readOnly: true
+      - name: docker-config-root
+        mountPath: /home/runner/.docker
       volumes:
       - name: rootless-dind-work-dir
         ephemeral:
@@ -105,6 +123,15 @@ spec:
               resources:
                 requests:
                   storage: 3Gi
+      - name: docker-config
+        # Refer to .dockerconfigjson/.docker/config.json
+        secret:
+          secretName: docker-config
+          items:
+          - key: .dockerconfigjson
+            path: config.json
+      - name: docker-config-root
+        emptyDir: {}
 
       #
       # Non-standard working directory