Overview

A sample project that demonstrates how a NodeJS REST API can be Dockerized and auto-deployed using GitLab CI/CD. Deployments are handled over SSH.

NodeJS REST API

Install Dependencies

Install the dependencies with the following command:

nvm use
npm install

Launch Development Server

To run a build and launch the development server, execute:

npm start

Routes

Once completed, the REST API should be avialable at the following routes:

GET http://localhost:3000/info

Returns an example JSON response to confirm the API endpoint is accessible.

Docker

This repo is configured with GitLab CI to build and deploy a docker image whenever changes are commited. The Docker image will be tagged with latest as well as the version listed in the package.json.

Image Build and Execution

The Image can be built using the standard docker build command. The docker run command can be used to launch the container, however network information and environment variables will need to be defined. Please see the how docker run is executed in the gitlab-ci.yaml as an example.

Endpoints

Once deployed into a Docker Runtime, the REST API's endpoints will be available on the local machine via:

• {host}:8882/info

GitLab Deployment

Changes will be deployed automatically to a configured Deployment Server (i.e. server being deployed to). For this to happen, ensure the following CI/CD variables are defined at either the group or project level in GitLab:

• STAGE_SERVER_IP - contains the IP address of the Deployment Server. This is the IP address used to make SSH connections from the GitLab Runner.
• STAGE_SERVER_USER - contains the user used when opening the SSH session.
• STAGE_ID_RSA - SSH private key file used to authenticate when opening the SSH session.

For more information on these variables, see section 2: Preparing the Staging Server on this blog post.

I also ran into issues with DinD (Docker in Docker) during the Docker image builds. Strange things like cannot connect to the docker daemon. Ultimate applying this fix to the GitLab Runner worked for me: https://gitlab.com/gitlab-org/gitlab-runner/-/issues/1986#note_20339074

Docker Debugging

Execute the following command to terminal into the running docker container:

docker exec -it node-docker-gitlab-ci /bin/sh

Supplemental Blog Post

Here is a blog post I created that explains this project and the CI/CD process in further detail: https://taylor.callsen.me/how-to-dockerize-a-nodejs-app-and-deploy-it-using-gitlab-ci/