# Continuous Integration & Continuous Delivery

CI/CD, short for continuous integration and continuous delivery/deployment, is a practice that aims to streamline and accelerate the software development lifecycle[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). It allows development teams to deliver code changes more frequently and quickly[4](https://www.abtasty.com/resources/ci-cd/)[5](https://www.opentext.com/what-is/ci-cd). CI/CD is supported by development and operations teams working together in an agile way, using either a DevOps or site reliability engineering (SRE) approach[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd).

**Continuous Integration (CI)**: CI is the practice of automatically and frequently integrating code changes into a shared source code repository[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). Developers submit code changes more frequently, which allows for continuous testing, faster bug fixes, better functionality, and ultimately, better collaboration and software quality[2](https://www.ibm.com/think/topics/ci-cd-pipeline). Taking snapshots of the source code can be done within a versioning tool like Git, allowing developers to freely work on new features and quickly revert the codebase to its previous state if a problem arises[2](https://www.ibm.com/think/topics/ci-cd-pipeline). After the automated build stage, a CI server compiles the source code changes into the main branch code, or "trunk," of the shared source code repository[2](https://www.ibm.com/think/topics/ci-cd-pipeline).

**Continuous Delivery (CD)**: CD automates the release of validated code to a repository after the automation of builds and unit and integration testing in CI[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). Every stage, from the merger of code changes to the delivery of production-ready builds, involves test automation and code release automation[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). The operations team can then swiftly deploy an app to production[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). The goal of continuous delivery is to deploy new code with minimal effort, while still allowing a level of human oversight[2](https://www.ibm.com/think/topics/ci-cd-pipeline).

**Continuous Deployment**: Continuous deployment automatically releases code changes to end-users after passing a series of predefined tests[2](https://www.ibm.com/think/topics/ci-cd-pipeline). Once the code passes testing, the deployment to production happens automatically, without the need for human approval[2](https://www.ibm.com/think/topics/ci-cd-pipeline). Continuous deployment is suitable for DevOps teams with a fast development lifecycle, such as those building e-commerce sites and software as a service (SaaS) platforms[2](https://www.ibm.com/think/topics/ci-cd-pipeline).

CI/CD helps organizations avoid bugs and code failures while maintaining a continuous cycle of software development and updates[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). As apps grow larger, features of CI/CD can help decrease complexity, increase efficiency, and streamline workflows[1](https://www.redhat.com/en/topics/devops/what-is-ci-cd). Because CI/CD automates the manual human intervention traditionally needed to get new code from a commit into production, downtime is minimized and code releases happen faster



CI/CD (Continuous Integration/Continuous Delivery or Deployment) streamlines the software development lifecycle by automating the processes of integrating code, testing, and deploying applications[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery)[3](https://www.redhat.com/en/topics/devops/what-is-ci-cd)[5](https://dev.to/miracool/leveraging-cicd-for-streamlined-software-development-and-deployment-4oj9). This automation leads to faster releases, improved code quality, and reduced risk[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery).

Here's how CI/CD streamlines the software development lifecycle:

* **Streamlines Code Integration:** CI automates the integration of code changes from multiple developers into a shared repository, which reduces conflicts and ensures a stable codebase[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery).
* **Automates Testing and Quality Control:** CI/CD automates testing by running a suite of tests, including unit, integration, and acceptance tests, every time a change is made. This provides immediate feedback on code quality, allowing developers to fix issues early[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery)[5](https://dev.to/miracool/leveraging-cicd-for-streamlined-software-development-and-deployment-4oj9).
* **Accelerates Software Delivery:** CD automates the deployment of code to various environments, ensuring code can be deployed at any time. Continuous Deployment automatically pushes every successful change into production, which reduces the time to release new features or bug fixes[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery).
* **Enhances Productivity and Collaboration:** By reducing manual tasks and ensuring code quality and consistency, CI/CD enhances the productivity and collaboration of developers[2](https://www.linkedin.com/advice/1/how-do-you-use-cicd-sdlc-skills-software-development-life-c).
* **Reduces Bugs and Downtime:** CI/CD helps organizations avoid bugs and code failures while maintaining a continuous cycle of software development and updates. It also minimizes downtime and accelerates code releases by automating manual intervention[3](https://www.redhat.com/en/topics/devops/what-is-ci-cd)[4](https://about.gitlab.com/topics/ci-cd/).
* **Faster Time to Market:** CI/CD pipelines enable development teams to release new features and updates quickly and efficiently. Automated processes enable frequent code integration, testing, and deployment, helping businesses stay competitive by addressing customer needs in real-time[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery).
* **Improved Code Quality:** Continuous automated testing is a core aspect of CI/CD, ensuring that every code change is validated before deployment. This reduces bugs and improves overall software quality, allowing teams to catch issues early in the process[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery).
* **Reduced Risk:** Frequent and smaller deployments make it easier to detect and fix issues early, reducing the chance of major disruptions. CI/CD pipelines also support rollback mechanisms, allowing developers to revert problematic changes without affecting other parts of the system[1](https://www.getambassador.io/blog/mastering-cicd-pipeline-streamlined-software-delivery).
* **Faster Recovery:** CI/CD makes it easier to fix issues and recover from incidents, reducing mean time to resolution (MTTR). Continuous deployment practices mean frequent small software updates so when bugs appear, it's easier to pinpoint them

## CI/CD and Agile

CI/CD (Continuous Integration/Continuous Delivery or Deployment) supports agile and iterative planning by aligning with the core principles of agile methodologies. Agile emphasizes flexibility, rapid iteration, and continuous improvement, which are all facilitated by CI/CD practices. Here's how CI/CD supports agile and iterative planning:

1. **Rapid Iteration and Feedback**:
   * **Agile Principle**: Agile emphasizes delivering working software in short cycles (sprints) and continuously gathering feedback.
   * **CI/CD Role**: CI/CD enables rapid iteration by automating the build, test, and deployment processes. This allows for frequent releases, which aligns with agile's iterative approach. Feedback from users or stakeholders can be quickly incorporated into the next iteration.
2. **Flexibility and Adaptability**:
   * **Agile Principle**: Agile methodologies are designed to be flexible, allowing teams to adapt to changing requirements.
   * **CI/CD Role**: CI/CD supports this flexibility by making it easier to integrate new code changes and test them quickly. This allows teams to pivot or adjust their development path based on new information or changing priorities.
3. **Continuous Improvement**:
   * **Agile Principle**: Agile encourages continuous improvement through retrospectives and iterative refinement.
   * **CI/CD Role**: CI/CD pipelines provide immediate feedback on code quality and functionality, which helps identify areas for improvement. This feedback loop supports continuous refinement and optimization of the development process.
4. **Reduced Risk**:
   * **Agile Principle**: Agile aims to reduce risk by breaking work into smaller, manageable chunks.
   * **CI/CD Role**: CI/CD reduces risk by automating testing and deployment, ensuring that each small change is validated before it reaches production. This approach minimizes the impact of any single change, aligning with agile's risk-reduction strategy.
5. **Collaboration and Transparency**:
   * **Agile Principle**: Agile emphasizes collaboration and transparency across teams.
   * **CI/CD Role**: CI/CD promotes collaboration by providing a shared understanding of the development process. Automated pipelines offer transparency into the status of code changes, allowing teams to work together more effectively.
6. **Faster Time to Market**:
   * **Agile Principle**: Agile aims to deliver value quickly to customers.
   * **CI/CD Role**: CI/CD accelerates the delivery of software by automating the entire pipeline from code commit to deployment. This enables agile teams to release new features and updates faster, aligning with the goal of delivering value quickly.

In summary, CI/CD supports agile and iterative planning by facilitating rapid iteration, flexibility, continuous improvement, reduced risk, collaboration, and faster time to market. These elements are crucial for agile methodologies, which focus on delivering high-quality software quickly and adapting to changing requirements.

## Tool Support

CI/CD (Continuous Integration/Continuous Delivery or Deployment) integrates with agile project management tools to streamline the software development lifecycle and enhance collaboration across teams. Here's how CI/CD integrates with agile project management tools:

### Integration Points

1. **Version Control Systems (VCS) Integration**:
   * **Tools**: Git, SVN
   * **Role**: CI/CD tools like Jenkins, GitLab CI/CD, or CircleCI integrate with version control systems to trigger builds and deployments automatically when code changes are pushed.
2. **Agile Project Management Tools**:
   * **Tools**: Jira, Trello, Asana
   * **Role**: These tools manage workflows, track issues, and plan sprints. CI/CD can be integrated to automate tasks, update issue statuses, or trigger deployments based on specific project milestones.
3. **Automated Testing and Quality Assurance**:
   * **Tools**: Selenium, Appium
   * **Role**: Automated testing tools are integrated into CI/CD pipelines to ensure code quality and functionality before deployment. Results can be fed back into agile tools to update test status or trigger further actions.
4. **Deployment and Monitoring**:
   * **Tools**: Docker, Kubernetes
   * **Role**: CI/CD integrates with deployment tools to automate the rollout of new versions. Monitoring tools can be linked to agile tools to provide insights into application performance and user feedback.

### Integration Mechanisms

1. **APIs and Webhooks**:
   * Many agile tools provide APIs and webhooks that allow CI/CD systems to interact with them programmatically. For example, when a build completes, a CI/CD tool can use an API to update the status of related issues in Jira.
2. **Plugins and Extensions**:
   * Both CI/CD and agile tools often support plugins or extensions that simplify integration. For instance, Jenkins has plugins for integrating with Jira to automate workflow updates.
3. **Automation Scripts**:
   * Custom scripts can be written to automate interactions between CI/CD and agile tools. These scripts can trigger actions based on specific events or conditions.

### Benefits of Integration

* **Enhanced Collaboration**: Integrating CI/CD with agile tools ensures that all stakeholders have a unified view of the development process, from planning to deployment.
* **Automated Workflows**: Automating tasks reduces manual effort and minimizes errors, allowing teams to focus on development and innovation.
* **Faster Feedback Loops**: Integration enables rapid feedback from automated testing and deployment, which is crucial for agile methodologies that emphasize continuous improvement.
* **Improved Transparency**: The integration provides real-time visibility into the status of code changes, deployments, and testing results, enhancing transparency across teams.

In summary, CI/CD integrates with agile project management tools through APIs, plugins, and automation scripts to enhance collaboration, automate workflows, and provide faster feedback loops. This integration supports the agile principles of flexibility, rapid iteration, and continuous improvement.
