Build Docker Image

We are going to make git repository on our local staging server and we will automate way the new version is deployed there.

Git Hook

When developer pushed code, the hook will checkout the code. Then it will build and tags docker image. When that is done, it restarts the servers.

We can have multiple git repositories on one server, that can become handy when we want to have a server with multiple services running

Lets create a git repository on the staging server. And add a hook that will rebuild the docker container.

#!/usr/bin/env bash
SSH_USER="ondrej"
SERVER_IP="192.168.1.199"

echo "Initialize git repo and hooks..."
scp "git/post-receive/mobydock" "${SSH_USER}@${SERVER_IP}:/tmp/mobydock"
ssh -t "${SSH_USER}@${SERVER_IP}" bash -c "'
sudo apt-get update && sudo apt-get install -y -q git
sudo rm -rf /var/git/mobydock.git /var/git/mobydock
sudo mkdir -p /var/git/mobydock.git /var/git/mobydock
sudo git --git-dir=/var/git/mobydock.git --bare init

sudo mv /tmp/mobydock /var/git/mobydock.git/hooks/post-receive
sudo chmod +x /var/git/mobydock.git/hooks/post-receive
sudo chown ${SSH_USER}:${SSH_USER} -R /var/git/mobydock.git /var/git/mobydock
'"
echo "done!"

Here is the git hook that will redeploy the application.

#!/usr/bin/env bash
SSH_USER="ondrej"
SERVER_IP="192.168.1.199"
REPO_NAME="mobydock"

# Check out the newest version of the code.
export GIT_WORK_TREE="/var/git/${REPO_NAME}"
git checkout -f

TAG="$(git log --pretty=format:'%h' -n 1)"
FULL_COMMIT_TAG="${REPO_NAME}:${TAG}"
FULL_LATEST_TAG="${REPO_NAME}:latest"

# Build the image with the proper commit tag.
docker build -t "${FULL_LATEST_TAG}" "${GIT_WORK_TREE}"

# Get the Docker ID of the last built image.
DOCKER_ID="$(docker images -q ${REPO_NAME} | head -1)"

# Tag a latest version based off a commit tag.
#docker tag -f "${DOCKER_ID}" "${FULL_LATEST_TAG}"

echo "Restarting ${REPO_NAME}"
docker stop "${REPO_NAME}"

echo "Removing untagged Docker images (may take a while)"
docker rmi $(docker images --quiet --filter "dangling=true")

Add remote for staging into git.

git remote add staging ssh://ondrej@192.168.1.199:/var/git/mobydock.git

If you need to know more, here are all the needed files.