bash script to build docker images of node apps via jenkins jobs. Requires jq and the Jenkins GitHub plugin.

docker.jenkins.github.sh

#!/usr/bin/env bash

# AWS domain
DOMAIN=${AWS_DOMAIN}

# Set CI_TEST to true to exit the script before build commences.
TEST=${CI_TEST:-'false'}

# Defaults for testing (variables supplied by Jenkins when in that environment).
GIT_URL=${GIT_URL:-"git@github.com:foo/foo-bar-baz-qux.git"}
BUILD_NUMBER=${BUILD_NUMBER:-456}
GIT_BRANCH=${GIT_BRANCH:-"origin/release"}

# GIT_BRANCH will be set to 'develop' if that string
# is at the end of GIT_BRANCH.
GIT_BRANCH=`echo ${GIT_BRANCH} | grep -o "develop$"`

# Get the version from package.json; requires "jq" to be installed.
VERSION=`cat ./package.json | jq -r ".version"`.${BUILD_NUMBER}

# Derive the IMAGE_NAME from GIT_URL env var supplied by Jenkins.
# NOTE: important to follow the convention: git repo name === image name
IMAGE_NAME=`echo ${GIT_URL} | grep -o "/.*\." | sed 's/^\/\(.*\).$/\1/'`

# Builds from develop branch are always "latest" tag.
# All other builds get the version number from package.json.
TAG=$([ "$GIT_BRANCH" == "develop" ] && echo "latest" || echo "$VERSION")

echo "Building image with tag: "${DOMAIN}/${IMAGE_NAME}:${TAG}

# Exit if testing.
[ "$TEST" == "true" ] && exit 0

# login to AWS
$(aws ecr get-login --region us-east-1)

# do the build and push to AWS
docker build -t ${DOMAIN}/${IMAGE_NAME}:${TAG} .

# clean up "latest" tags
if [ "$TAG" == "latest" ]; then
    echo "Removing from the registry: ${IMAGE_NAME}:${TAG}"
    aws ecr batch-delete-image --repository-name ${IMAGE_NAME} --image-ids imageTag=${TAG}
fi

docker push ${DOMAIN}/${IMAGE_NAME}:${TAG}