Basics of CI CD pipelines

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Table of Contents

Overview

A CI/CD pipeline is an automated workflow that enables teams to deliver software more frequently and reliably by automating the integration, testing, and deployment processes. It stands for Continuous Integration (CI) and Continuous Delivery/Deployment (CD). Containers are crucial in modern CI/CD pipelines, enhancing consistency, scalability, and efficiency throughout the software delivery process.

What’s a CI/CD pipeline?

Key Components of a CI/CD Pipeline:

Continuous Integration (CI):some text
- Definition: CI involves automatically integrating code changes from multiple developers into a shared repository many times a day. Every change triggers a build and test process, ensuring that new code integrates smoothly with the existing codebase.
- Process:some text
  - Code Commit: Developers commit code to a shared version control system (like Git).
  - Automated Build: The CI server (such as Jenkins, Travis CI, or a cloud-based service) automatically builds the application.
  - Automated Testing: The pipeline runs automated tests (unit, integration, etc.) to validate the code.
Continuous Delivery (CD):some text
- Definition: CD ensures that the codebase is always in a deployable state. After successful CI, the application is automatically prepared for release into production, but human intervention is required to actually deploy it.
- Process:some text
  - Staging Environment: The application is deployed to a staging environment where it undergoes further testing, including user acceptance tests.
  - Manual Approval: A manual approval step is often included to review the changes before deploying to production.
Continuous Deployment (CD):some text
- Definition: Continuous Deployment goes a step further by automating the deployment of code to production without requiring manual approval, provided that the code passes all automated tests and checks.
- Process:some text
  - Automatic Deployment: Once the code passes the pipeline’s tests, it is automatically deployed to production.
  - Monitoring and Rollback: Continuous monitoring is set up to detect any issues in the live environment, and rollback mechanisms are in place to revert to a previous stable version if necessary.

Containers and CI/CD pipelines

Here's how containers fit into a CI/CD pipeline:

Role of Containers in CI/CD:

Consistency Across Environments:some text
- Definition: Containers encapsulate an application and its dependencies in a single, portable unit, ensuring that the application runs consistently across different environments (development, testing, production).
- Benefit: This eliminates the common "it works on my machine" problem by providing a consistent runtime environment, which is crucial in CI/CD pipelines.
Simplified Integration and Testing:some text
- Continuous Integration:some text
  - During the CI process, code changes are integrated into the main codebase, and automated builds are triggered. Containers are used to package the application along with all its dependencies, ensuring that the build process is consistent.
  - Testing in Containers: Automated tests can be run within containers, providing an isolated and consistent environment for unit, integration, and end-to-end tests. This ensures that the tests reflect how the application will behave in production.
Efficient Deployment:some text
- Continuous Delivery/Deployment:some text
  - Once the application passes the CI process, it is packaged into a container image. This image becomes the artifact that is deployed through the CD pipeline.
  - Immutable Artifacts: Container images are immutable, meaning that the exact same image that was tested can be deployed to production, reducing the risk of discrepancies between environments.
  - Orchestration: Platforms like Kubernetes, often integrated with Harness.io, manage the deployment of containers at scale, automating tasks such as load balancing, scaling, and self-healing.
Version Control and Rollbacks:some text
- Versioning: Container images are versioned and stored in a container registry (such as Docker Hub or AWS ECR). Each version corresponds to a specific state of the application, making it easy to track changes and roll back to a previous version if necessary.
- Rollback Mechanism: In the event of a deployment failure, Harness.io can use container versions to quickly roll back to the last known good state, minimizing downtime and disruption.
Microservices Architecture:some text
- Support for Microservices: Containers align perfectly with microservices architecture, where each service is packaged and deployed independently. This allows for greater flexibility and scalability in the CI/CD pipeline, as individual services can be updated, tested, and deployed without affecting the entire system.

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What is the Harness CI/CD pipeline?

Harness CI/CD pipeline is a comprehensive, automated solution provided by Harness that enables software teams to streamline the application delivery process from development to production. It integrates Continuous Integration (CI) and Continuous Delivery/Deployment (CD) into a unified workflow, allowing teams to build, test, deploy, and monitor applications with minimal manual intervention. CI executes steps as containers, packaging code, and dependencies in isolation from other steps.

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The standout features Harness CI/CD are:

Test Intelligence
Continuous Verification
Using AI to debug and remediate pipeline issues

Benefits of Harness CI/CD Pipeline:

Speed and Efficiency: Automation reduces the time and effort needed to build, test, and deploy applications, allowing for faster release cycles.
Reliability: Continuous testing and verification ensure that only high-quality code is deployed to production, reducing the risk of downtime.
Ease of Use: Harness’s visual editor and out-of-the-box integrations simplify the setup and management of CI/CD pipelines, making them accessible to both developers and operations teams.
Cost Optimization: By automating deployment strategies like canary and blue/green, Harness helps teams optimize infrastructure usage and reduce cloud costs.

Harness CI/CD pipeline is a powerful tool that automates the entire software delivery process, making it easier for teams to deliver high-quality applications quickly and reliably. Get started on Harness CI.