backport release test to 3.4

Signed-off-by: Benjamin Wang <wachao@vmware.com>

.github/workflows/release.yaml

@@ -0,0 +1,24 @@
+name: Release
+on: [push, pull_request]
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-go@v2
+      with:
+        go-version: "1.16.15"
+    - run: |
+        git config --global user.email "github-action@etcd.io"
+        git config --global user.name "Github Action"
+        gpg --batch --gen-key <<EOF
+        %no-protection
+        Key-Type: 1
+        Key-Length: 2048
+        Subkey-Type: 1
+        Subkey-Length: 2048
+        Name-Real: Github Action
+        Name-Email: github-action@etcd.io
+        Expire-Date: 0
+        EOF
+        DRY_RUN=true ./scripts/release.sh --no-upload --no-docker-push 3.4.99

scripts/release.sh

@@ -61,14 +61,16 @@ main() {
   cd "${reldir}/etcd"
 
   # If a release version tag already exists, use it.
+  log_callout "Checking tag: ${RELEASE_VERSION}"
   local remote_tag_exists
-  remote_tag_exists=$(git ls-remote origin "refs/tags/${RELEASE_VERSION}" | grep -c "${RELEASE_VERSION}")
+  remote_tag_exists=$(git ls-remote origin "refs/tags/${RELEASE_VERSION}" | grep -c "${RELEASE_VERSION}" || true)
   if [ "${remote_tag_exists}" -gt 0 ]; then
     log_callout "Release version tag exists on remote. Checking out refs/tags/${RELEASE_VERSION}"
     git checkout -q "tags/${RELEASE_VERSION}"
   fi
 
   # Check go version.
+  log_callout "Checking go version"
   local go_version current_go_version
   go_version="go$(grep go-version .github/workflows/tests.yaml | awk '{print $2}' | tr -d '"')"
   current_go_version=$(go version | awk '{ print $3 }')
@@ -139,7 +141,7 @@ main() {
 
     # Verify the version tag is on the right branch
     # shellcheck disable=SC2155
-    local branch=$(git branch --contains "${RELEASE_VERSION}")
+    local branch=$(git for-each-ref --contains "${RELEASE_VERSION}" --format="%(refname)" 'refs/heads' | cut -d '/' -f 3)
     if [ "${branch}" != "release-${MINOR_VERSION}" ]; then
       log_error "Error: Git tag ${RELEASE_VERSION} should be on branch release-${MINOR_VERSION} but is on ${branch}"
       exit 1