Continuous Integration is a development practice that requires developers to integrate code into a shared repository several times per day (repos in subversion, CVS, git). Each check-in is then verified by an automated build, allowing everyone to detect and be notified of problems with the package immediately.

Build Pipeline is a process by which the software build is broken down in sections: 

1. Unit test 
2. Acceptance test 
3. Packaging 
4. Reporting 
5. Deployment 
6. Notification

The concepts of Continuous Integration, Build Pipeline and the new “DevOps” movement are revolutionizing how we build, deploy and use software. Gitlab is providing the automated pipeline which we need to use the gitlab.yml file.

I am unable to find the docker image which is appropriate for the php version and composer version we are using in our app. So I go with a manual gitlab runner.

Gitlab runner configuration: I installed the gitlab runner and initialized it in the aws ubuntu ec2 instance with the following steps:

# Download the binary for your system

sudo curl -L –output /usr/local/bin/gitlab-runner https://gitlab-runner-downloads.s3.amazonaws.com/latest/binaries/gitlab-runner-linux-amd64

# Give it permissions to execute

sudo chmod +x /usr/local/bin/gitlab-runner

# Create a GitLab CI user

sudo useradd –comment ‘GitLab Runner’ –create-home gitlab-runner –shell /bin/bash

# Install and run as service

sudo gitlab-runner install –user=gitlab-runner –working-directory=/home/gitlab-runner

sudo gitlab-runner start

For registering the runner in use the following command: 

sudo gitlab-runner register –url https://gitlab.com/ –registration-token $REGISTRATION_TOKEN

After installation, I tried to use the entire ec2 instance as a runner which will be more easy to deploy the application by using ssh as executor. I added pem file as the ssh key in the gitlab cicd variables and also stored the key in ec2 instance  location /home/ubuntu/.ssh. This runner uses aws environment as its own environment and doesn’t need anything to install. 

 But this runner failed because due to some configuration in the AWS EC2 instance while I logged into the instance with root through the pipeline, it logged out automatically. So I rewrote the config file of gitlab runner (replaced executor as shell). This change allows Pipeline to login to the instance, but doesn’t allow the git to pull the files. 

SSH Key generation and adding to Gitlab: To allow the git to pull the files from gitlab add the ssh key into the gitlab account. Generate ssh key by using 

ssh-keygen -o -f ~/.ssh/id_rsa

This generates an rsa ssh key.