Update release.sh to push branch & tag to GitHub. (#68)

Author: StevenYCChou

release.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 version="$1"
+versioned_release_branch="release-${version}"
+versioned_release_tag="v${version}"
 
 if [[ -z "${version}" ]]; then
     echo "Please provide a version: ./release.sh {VERSION}"
@@ -21,7 +23,24 @@ fi
 echo "${version}" > VERSION
 
 # 2. Create a git branch for the version, e.g. `release-0.3.1`.
-git checkout -b "release-${version}"
+git checkout -b "${versioned_release_branch}"
 
-# 3. Run `DOCKER_IMAGE_NAME={public_docker_image} make push`.
+# 3. Commit the version update.
+git add VERSION
+git commit -m "Update version to ${version}."
+
+# 4. Run `DOCKER_IMAGE_NAME={public_docker_image} make push`.
 DOCKER_IMAGE_NAME="gcr.io/stackdriver-prometheus/stackdriver-prometheus-sidecar" make push
+
+################################
+# Push branch and tag to GitHub
+################################
+# 1. Tag the commit to a specific version, e.g. `v0.3.1`. 
+git tag "${versioned_release_tag}"
+
+# 2. Push release branch to GitHub.
+git push https://github.com/Stackdriver/stackdriver-prometheus-sidecar.git "${versioned_release_branch}"
+
+# 3. Push tag to GitHub.
+git push https://github.com/Stackdriver/stackdriver-prometheus-sidecar.git "${versioned_release_tag}"
+