get GitHub git branch for AWS CodeBuild

问题

I'm setup AWS CodeBuild to build automatically from GitHub. Other CI services provide an environment variable for the branch, but I can't find one for AWS CodeBuild. There is a CODEBUILD_SOURCE_VERSION that is set to either pr/7 where 7 is the pull request number or the git commit sha.

Given the commit sha, I've been trying to get the branch name, but no luck so far.

git branch --contains <commitsha> doesn't work because it is a detached head. How do I get the git branch for the commit from CodeBuild?

回答1:

You can run:

git branch -a --contains <sha>

-a means all branches. If your sha is in no branch, which could happen in some cases, you won't see anything.

回答2:

You can get inspired by https://github.com/thii/aws-codebuild-extras

⚠️I don't recommend to run the curl command for security sake! If some vilain stole access to the thii/aws-codebuild-extras repo, you are screwed!

Just copy paste the script (understand it!) and add it to your docker image and then call it from your file system.

#!/bin/bash

export CI=true
export CODEBUILD=true

export CODEBUILD_GIT_BRANCH=`git symbolic-ref HEAD --short 2>/dev/null`
if [ "$CODEBUILD_GIT_BRANCH" == "" ] ; then
  CODEBUILD_GIT_BRANCH=`git branch -a --contains HEAD | sed -n 2p | awk '{ printf $1 }'`
  export CODEBUILD_GIT_BRANCH=${CODEBUILD_GIT_BRANCH#remotes/origin/}
fi

export CODEBUILD_GIT_MESSAGE=`git log -1 --pretty=%B`
export CODEBUILD_GIT_AUTHOR=`git log -1 --pretty=%an`
export CODEBUILD_GIT_AUTHOR_EMAIL=`git log -1 --pretty=%ae`
export CODEBUILD_GIT_COMMIT=`git log -1 --pretty=%H`
export CODEBUILD_GIT_TAG=`git describe --tags --abbrev=0`

export CODEBUILD_PULL_REQUEST=false
if [[ $CODEBUILD_GIT_BRANCH == pr-* ]] ; then
  export CODEBUILD_PULL_REQUEST=${CODEBUILD_GIT_BRANCH#pr-}
fi

export CODEBUILD_PROJECT=${CODEBUILD_BUILD_ID%:$CODEBUILD_LOG_PATH}
export CODEBUILD_BUILD_URL=https://$AWS_DEFAULT_REGION.console.aws.amazon.com/codebuild/home?region=$AWS_DEFAULT_REGION#/builds/$CODEBUILD_BUILD_ID/view/new

echo "==> AWS CodeBuild Extra Environment Variables:"
echo "==> CI = $CI"
echo "==> CODEBUILD = $CODEBUILD"
echo "==> CODEBUILD_GIT_AUTHOR = $CODEBUILD_GIT_AUTHOR"
echo "==> CODEBUILD_GIT_AUTHOR_EMAIL = $CODEBUILD_GIT_AUTHOR_EMAIL"
echo "==> CODEBUILD_GIT_BRANCH = $CODEBUILD_GIT_BRANCH "
echo "==> CODEBUILD_GIT_COMMIT = $CODEBUILD_GIT_COMMIT"
echo "==> CODEBUILD_GIT_MESSAGE = $CODEBUILD_GIT_MESSAGE"
echo "==> CODEBUILD_GIT_TAG = $CODEBUILD_GIT_TAG"
echo "==> CODEBUILD_PROJECT = $CODEBUILD_PROJECT"
echo "==> CODEBUILD_PULL_REQUEST = $CODEBUILD_PULL_REQUEST"

回答3:

Add the following command to the install or pre_build phase of your buildspec.yml:

bash -c "$(curl -fsSL https://raw.githubusercontent.com/thii/aws-codebuild-extras/master/install)"

You can get more information about the build via the following environment variables: CI, CODEBUILD, CODEBUILD_GIT_AUTHOR, CODEBUILD_GIT_AUTHOR_EMAIL, CODEBUILD_GIT_BRANCH, CODEBUILD_GIT_COMMIT, CODEBUILD_GIT_MESSAGE, CODEBUILD_GIT_TAG, CODEBUILD_PROJECT, CODEBUILD_PULL_REQUEST.

回答4:

It's now possible to obtain this information directly from CodeBuild environmental variables:

CODEBUILD_WEBHOOK_BASE_REF: The base reference name of the webhook event that triggers the current build. For a pull request, this is the branch reference.

CODEBUILD_WEBHOOK_HEAD_REF: The head reference name of the webhook event that triggers the current build. It can be a branch reference or a tag reference.

CODEBUILD_WEBHOOK_TRIGGER: Shows the webhook event that triggered the build. This variable is available only for builds triggered by a webhook. The value is parsed from the payload sent to CodeBuild by Github, Github Enterprise, or Bitbucket. The value's format depends on what type of event triggered the build.
For builds triggered by a pull request, it is pr/pull-request-number.

For builds triggered by creating a new branch or pushing a commit to a branch, it is branch/branch-name.

For builds triggered by a pushing a tag to a repository, it is tag/tag-name.

回答5:

CodeBuild strips git information from the filesystem. There is no .git folder, so running a git command will be fruitless.

I have added a parameter to my CI/CD CloudFormation template:

  GitBranch:
    Description: Github branch to be deployed
    Type: String
    Default: master

And I have a Bash script that creates / updates the CI/CD stack:

readonly git_branch=$(git branch 2>/dev/null | grep "^*" | colrm 1 2)

aws cloudformation create-stack \
  --stack-name ${cicd_stack_name} \
  --parameters ParameterKey=GitBranch,ParameterValue=${git_branch}

I then export the value as an environment variable to CodeBuild machine:

CodeBuildProject:
Type: AWS::CodeBuild::Project
Properties:
  Environment:
    Type: LINUX_CONTAINER
    Image: aws/codebuild/java:openjdk-8
    EnvironmentVariables:
      - Name: GIT_BRANCH
        Value: !Ref GitBranch

Now I have access to it in my buildspec.yml:

post_build:
  commands:
    - echo [PHASE] Entered the post_build phase...
    - echo "[DEBUG] Git branch ${GIT_BRANCH}"

来源：https://stackoverflow.com/questions/47657423/get-github-git-branch-for-aws-codebuild

标签

git

amazon-web-services

aws-codebuild