Rootconf Mini 2024

Abstract

Building a CI/CD pipeline capable of supporting 500+ engineers, and managing 600+ deployments across 300+ services daily is essential at Zomato’s scale. Efficient CI/CD pipelines are critical for streamlining the development process and ensuring secure deployments.

In this session, we’ll cover how we revamped our CI/CD setup using self-hosted GitHub Actions to overcome these challenges.

We’ll explore

Problems with the existing setup on AWS CodePipeline and CodeBuild

• Dependency on the SRE team: Adding a new CI check or deployment pipeline requires spawning AWS resources, making the process dependent on SRE intervention.
• Fragmented workflow: Developers need to switch between GitHub and AWS to trigger or monitor CI checks and deployments while also managing separate access controls for AWS.
• Newcomers face a challenging learning curve due to the complexity of the setup.
• Lack of Trigger Visibility and Traceability. Additionally, It was difficult to customize or take override inputs from services for common pipelines.
• The absence of canary deployments was a major limitation, requiring us to deploy only during low-traffic periods.
• Missing features like Revert, Auto Abort, Manual Approval, etc.

How we orchestrated our self-hosted Github Action infrastructure

• From placing the job on runners to monitoring and alerting the failures.
• Ensuring no resource wastage by having a controller to maintain the pool of runners. leveraging spot instances without affecting the developer experience.
• Fully private architecture with internal service communication with integration test support.
• Observability: Runner, Workflow, and job Level Monitoring
• Custom features we built to improve job runtimes and developer experience. Ex: Package caching, Proto caching, Notifications on failures, Dynamic resource allocation to Jobs.
• Next Steps:
  • Docker Image Caching

An overview of how the CI/CD flow looks and how the developer experience has improved. Covering Features:

• Unified Platform: No more tool-switching between GitHub and AWS CodeBuild.
• How we used Reusable workflows in services across different languages to run customizable linters.
• Overview of merge and release workflows, including developer forks, branch management (dev, master branches), and the pull request flow.
• Canary Deployment support
• Continuous Monitoring of Services during deployment, with automated rollback or manual decisions to abort or continue in case of errors.
• One-click Revert
• Deploy Services in multiple accounts and regions within the same deployment.
• Dynamic deployment access management
• Hotfix deployments
• Next Steps:
  • Standardize build spec

Key Takeaways

• Building orchestration for self-hosted GitHub Actions and observability around it.
• Enhancing the CI/CD experience for developers while ensuring robustness.

Target Audience

• DevOps and SRE engineers interested in CI/CD automation.
• Anyone planning to implement self-hosted GitHub Actions orchestration for their workflows.