January 20, 2025 9 min to read

What is GitLab, GitLab Runner?

A comprehensive guide to GitLab, GitLab Runner installation and configuration

Overview

Let’s explore GitLab, a comprehensive DevOps platform that provides tools for software development, deployment, and collaboration. GitLab helps teams efficiently plan, create, test, and deploy their software projects.

What is GitLab?

GitLab is a web-based DevOps platform that provides an all-in-one solution for software development and collaboration. It offers tools and features that help teams plan, create, build, test, and deploy software projects more efficiently.

GitLab combines version control, issue tracking, CI/CD pipelines, and more into a single, integrated platform.

Key Features:

Installation Guide (Ubuntu 18.04/20.04/22.04)

1️⃣ System Update & Package Installation

# Update System
sudo apt update
sudo apt upgrade -y

# Install Required Packages
sudo apt install -y ca-certificates curl openssh-server tzdata

2️⃣ Add GitLab CE Repository

# Install Dependencies
sudo apt install curl debian-archive-keyring lsb-release ca-certificates apt-transport-https software-properties-common -y

# Add GitLab Repository
curl -sS https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh | sudo bash

3️⃣ Install and Configure GitLab

# Install GitLab CE
sudo EXTERNAL_URL="https://gitlab.example.com/" apt-get install gitlab-ce

# Configure SSL (Cloud Environment)
echo "letsencrypt['enable'] = false" | sudo tee -a /etc/gitlab/gitlab.rb
sudo gitlab-ctl reconfigure
sudo gitlab-ctl restart

Important Directories

Recommended Storage Configuration

# Example Storage Mount
/dev/xvdb1  2.0T  310G  1.6T  17%  /var/opt/gitlab/gitlab-rails/shared/lfs-objects
/dev/xvdc1  984G  273G  661G  30%  /var/opt/gitlab/git-data

Basic Management Commands

# Reconfigure GitLab
sudo gitlab-ctl reconfigure

# Restart GitLab
sudo gitlab-ctl restart

# Check GitLab Status
sudo gitlab-ctl status

# View Initial Root Password
sudo cat /etc/gitlab/initial_root_password

Backup and Restore

# Create a backup (default location: /var/opt/gitlab/backups)
sudo gitlab-backup create

# Create a backup with specific options
sudo gitlab-backup create STRATEGY=copy SKIP=uploads,repositories,builds GZIP_RSYNCABLE=yes

# Restore from a backup (for GitLab 14.0+)
sudo gitlab-backup restore BACKUP=1640289825_2021_12_23_14.6.3

# Backup GitLab configuration files
sudo cp /etc/gitlab/gitlab-secrets.json /var/opt/gitlab/backups/gitlab-secrets.json
sudo cp /etc/gitlab/gitlab.rb /var/opt/gitlab/backups/gitlab.rb

Performance Tuning

For larger installations, you can optimize GitLab performance by editing /etc/gitlab/gitlab.rb

# CPU and memory optimization
puma['worker_processes'] = 4
puma['max_threads'] = 4
sidekiq['concurrency'] = 20

# PostgreSQL optimization
postgresql['shared_buffers'] = "2GB"
postgresql['work_mem'] = "128MB"
postgresql['maintenance_work_mem'] = "256MB"

# Redis optimization
redis['tcp_timeout'] = 60
redis['tcp_keepalive'] = 300

# Apply changes
# sudo gitlab-ctl reconfigure

GitLab Runner

🔍 What is GitLab Runner?

GitLab Runner is a CI tool that works with GitLab to automatically build, test, and deploy code changes. It’s an open-source project that executes jobs in CI/CD pipelines on systems called Runners.

GitLab Runner can be installed on various operating systems and platforms, including Linux, macOS, Windows, and Kubernetes clusters.

How GitLab Runner Works:

1. When code changes are pushed to a GitLab repository with CI/CD pipeline configured
2. GitLab creates a new pipeline with one or more jobs
3. GitLab Runner periodically checks for new jobs
4. Runner executes the job steps defined in .gitlab-ci.yml
5. Runner sends real-time updates and logs back to GitLab

Types of Runners

Runner Executor Types

Installation Guide (Helm)

1️⃣ Prerequisites

# Add GitLab Helm Repository
helm repo add gitlab https://charts.gitlab.io/
helm repo update

2️⃣ Create values.yaml

3️⃣ Install GitLab Runner

# Create namespace
kubectl create namespace gitlab-runner

# Install Runner
helm install gitlab-runner -n gitlab-runner -f values.yaml gitlab/gitlab-runner

# Upgrade Runner
helm upgrade gitlab-runner -n gitlab-runner -f values.yaml gitlab/gitlab-runner

Basic GitLab Runner CLI Commands

Example .gitlab-ci.yml File

Here’s a basic .gitlab-ci.yml file to get started with CI/CD:

Advanced Runner Configuration

Cache Configuration

Optimize build times by caching dependencies:

# In .gitlab-ci.yml
cache:
  key: '${CI_COMMIT_REF_SLUG}'
  paths:
    - node_modules/
    - .npm/
    - vendor/
    - .gradle/

# Runner config.toml cache settings
[runners.cache]
  Type = "s3"
  Path = "gitlab-runner"
  Shared = true
  [runners.cache.s3]
    ServerAddress = "s3.amazonaws.com"
    AccessKey = "AWSACCESSKEY"
    SecretKey = "AWSSECRETKEY"
    BucketName = "my-bucket"
    BucketLocation = "us-east-1"

Auto-scaling Runners on Kubernetes

For efficient resource usage, configure auto-scaling:

# In Helm values.yaml
concurrent: 10
checkInterval: 30

runners:
  config: |
    [[runners]]
      [runners.kubernetes]
        image = "ubuntu:20.04"
        privileged = true
        namespace = "gitlab-runner"
        poll_timeout = 600
        cpu_request = "300m"
        cpu_limit = "1000m"
        memory_request = "500Mi"
        memory_limit = "2Gi"
        service_cpu_request = "100m"
        service_cpu_limit = "200m"
        service_memory_request = "100Mi"
        service_memory_limit = "200Mi"
        helper_cpu_request = "100m"
        helper_cpu_limit = "200m"
        helper_memory_request = "100Mi"
        helper_memory_limit = "200Mi"

Troubleshooting

GitLab Runner Debug Commands

# Run runner with debug output
sudo gitlab-runner --debug run

# Show detailed runner information
sudo gitlab-runner verify --verbose

# Check runner config file
cat /etc/gitlab-runner/config.toml

# Test runner connection
gitlab-runner verify --name YOUR_RUNNER_NAME

# Check pod status (for Kubernetes runners)
kubectl get pods -n gitlab-runner

# Check runner pod logs
kubectl logs -n gitlab-runner $(kubectl get pods -n gitlab-runner -l app=gitlab-runner -o name)

Best Practices

Reference

• GitLab Documentation
• GitLab Installation Guide
• GitLab Runner Documentation
• GitLab Runner Helm Chart
• GitLab Runner Kubernetes Installation