CI/CD is an important part of modern software development practices. ‘Continuous Integration’ refers to integrating code into a shared repository several times a day. Each integration is then automatically tested and validated, allowing developers to detect errors quickly and locate them more easily.
‘Continuous Deployment’ is a strategy that minimizes the time elapsed between writing a line of code and making that code available to users in production. This delivers value quickly and produces robust and reliable software.
By enabling fast and reliable delivery of changes, CI/CD practices help to increase the speed and stability of the development process.
2. AWS Tools for CI/CD
AWS offers several services that can be combined to create a robust CI/CD pipeline:
- AWS CodeCommit: A fully-managed source control service to host secure and scalable Git repositories.
- AWS CodeBuild: A fully-managed CI service that compiles source code, runs tests, and produces software packages.
- AWS CodeDeploy: A fully-managed deployment service that automates software deployments to a variety of AWS services.
- AWS CodePipeline: A fully-managed continuous delivery service that helps to automate the release pipelines for fast and reliable updates.
- AWS CodeStar: A fully-managed platform that enables developers to develop, build, and deploy applications on AWS.
3. Basic CI/CD Workflow with AWS
Here’s a typical workflow:
- Developers write code and commit changes to AWS CodeCommit.
- AWS CodePipeline detects changes in the CodeCommit repository.
- It then triggers AWS CodeBuild, which compiles the code, runs any tests, and produces a deployable version of the application.
- AWS CodePipeline then deploys the ‘build’ to the AWS CodeDeploy service.
- AWS CodeDeploy automated deployment service then deploys the application to AWS services such as EC2, Fargate, or Lambda.
- From here on, the application is live and in service.
4. Sample Architecture of CI/CD Workflow in AWS
Here’s a sample architecture with AWS services integrated into a complete CI/CD workflow.
- CodeCommit: Stores the source code and version history securely.
- CodeBuild: Compiles the source code and runs unit tests.
- CodePipeline: Orchestrates the workflow.
- CodeDeploy: Deploys the built code onto the EC2 instances.
- EC2 instances: Run the deployed application.
| AWS Services | Responsibilities |
|---|---|
| AWS CodeCommit | A secure repo where developers will check-in their code |
| AWS CodeBuild | Fetches code from CodeCommit, builds it, and executes unit tests |
| AWS CodeDeploy | Automates the application deployment on EC2 instances |
| AWS CodePipeline | Manages end-to-end CI/CD workflow |
| AWS Elastic Compute Cloud (EC2) | Hosts the application which is being developed |
AWS services offer a robust and integrated solution that supports agile practices like Continuous Integration and Continuous Deployment. This ensures faster, reliable builds, updates, and deployments. The flexibility and scalability of AWS services mean that developers can conceive, develop, test, and deploy applications seamlessly. With constant support and continuous updates, developers have an optimized environment for producing quality software at a quick pace.
Practice Test
True or False: AWS CodePipeline is a fully managed continuous integration and continuous delivery service that helps to automate your release workflows.
- True
- False
Answer: True
Explanation: AWS CodePipeline is a fully managed CI/CD service that directly helps you automate your workflows.
Which AWS service to use for source control and to store the code?
- A. AWS CodeDeploy
- B. AWS CodeCommit
- C. AWS Lambda
- D. AWS S3
Answer: B. AWS CodeCommit
Explanation: AWS CodeCommit is a fully-managed source control service that hosts secure Git-based repositories. It is the equivalent of a private GitHub repository.
True or False: AWS CodeBuild is a fully managed build service that runs Lambda function applications.
- True
- False
Answer: False
Explanation: AWS CodeBuild is indeed a fully managed build service, but it compiles source code, runs tests, and produces packages that are ready to deploy. It is not tied solely to Lambda functions.
Which AWS service allows you to automate your deployments to Amazon EC2 instances?
- A. AWS CodeDeploy
- B. AWS CodePipeline
- C. AWS CodeStar
- D. AWS CodeCommit
Answer: A. AWS CodeDeploy
Explanation: AWS CodeDeploy helps users to automate your deployments to instances and to update the applications running on instances.
True or False: Using AWS CI/CD tools, you cannot deploy application changes across different AWS regions.
- True
- False
Answer: False
Explanation: AWS CI/CD tools are designed to deploy changes across different AWS regions. You can use CodeCommit, CodeBuild, CodeDeploy and CodePipeline to create an end-to-end, multi-region continuous deployment pipeline.
True or False: AWS CodeStar enables you to quickly develop, build and deploy applications on AWS.
- True
- False
Answer: True
Explanation: AWS CodeStar provides a unified user interface, enabling you to manage your entire software development activity in one place.
AWS CodePipeline integrates with which of the following tools?
- A. AWS Elastic Beanstalk
- B. AWS RDS
- C. AWS CloudFormation
- D. Both A & C
Answer: D. Both A & C
Explanation: AWS CodePipeline integrates with tools like AWS Elastic Beanstalk, AWS OpsWorks, AWS CloudFormation, AWS ECS, AWS Fargate, and AWS Lambda.
True or False: AWS CodeDeploy can be used for automated deployments only.
- True
- False
Answer: False
Explanation: AWS CodeDeploy can be used for both manual and automated deployments.
Can we use AWS CodeBuild with Docker?
- A. Yes
- B. No
Answer: A. Yes
Explanation: AWS CodeBuild is a service that builds Docker images, and you can use Docker images to customize your runtime environments in CodeBuild.
True or False: AWS CodeBuild builds your source code and runs unit tests, but cannot produce a software package.
- True
- False
Answer: False
Explanation: AWS CodeBuild not only compiles your source code and runs tests, but also produces a software package that you can deploy.
In AWS CI/CD, who is responsible for the maintenance, patching and capacity planning of the underlying infrastructure?
- A. User
- B. AWS
Answer: B. AWS
Explanation: In AWS CI/CD, AWS is responsible for the infrastructure. This involves maintenance, patching, and capacity planning.
True or False: AWS CodeBuild launches a new build instance for every build and every instance runs in isolation.
- True
- False
Answer: True
Explanation: For every individual build, AWS CodeBuild launches a new build instance and runs it in its own isolated environment. This prevents any conflicts between builds.
Which AWS service can you use to quickly setup CI/CD workflows for your applications stored in GitHub repositories?
- A. AWS CodeCommit
- B. AWS CodeDeploy
- C. AWS CodeStar
- D. AWS CodePipeline
Answer: C. AWS CodeStar
Explanation: AWS CodeStar can quickly setup CI/CD workflows for your applications and it directly integrates with GitHub.
True or False: AWS CodePipeline does not have the ability to roll back to a previous version.
- True
- False
Answer: False
Explanation: AWS CodePipeline, used in conjunction with AWS CodeDeploy, does have the ability to roll back to a previous version.
What is the role of AWS CodeCommit in a CI/CD workflow?
- A. To deploy the code
- B. To run the code
- C. To build the code
- D. To store the code
Answer: D. To store the code
Explanation: AWS CodeCommit is used to store the code and track changes to the code. It’s an equivalent of a private GitHub repository.
Interview Questions
What is the primary service that AWS provides for CI/CD workflows?
The primary service AWS provides for CI/CD workflows is AWS CodePipeline.
Which AWS service is often used along with AWS CodePipeline for source control management?
AWS CodeCommit is often used along with AWS CodePipeline for source control management.
What AWS service allows for automated builds and test phases in the CI/CD pipeline?
AWS CodeBuild allows for automated builds and test phases in the CI/CD pipeline.
What does AWS CodeDeploy do in the CI/CD workflow?
AWS CodeDeploy is used to automate the deployment of applications to specified compute environments including EC2 instances, ECS services, or Lambda functions.
Which AWS service is used for configuring the end-to-end CI/CD workflow?
AWS CodeStar is used for configuring end-to-end CI/CD workflows.
Which AWS service is used for defining the deployment strategies and health checks within a CI/CD workflow?
AWS CodeDeploy is used for defining the deployment strategies and health checks within a CI/CD workflow.
What is the role of AWS CodeCommit in the CI/CD pipeline?
AWS CodeCommit is a source control service that hosts secure Git-based repositories which aids in the collaborative development and delivery of the code in the CI/CD pipeline.
What is the role of AWS Elastic Beanstalk in a CI/CD workflow?
AWS Elastic Beanstalk simplifies the deployment and scaling of applications developed with Java, .NET, PHP, Node.js, Python, Ruby, Go, and Docker on familiar servers such as Apache, Nginx, Passenger, and IIS.
Which AWS service notifies users about the operations performed in the pipeline?
Amazon CloudWatch is the service that provides notifications about the operations performed in the pipeline.
Which AWS service is used to create repeatable deployments of applications and application infrastructure?
AWS CloudFormation is used to create repeatable deployments of applications and application infrastructure.
In a CI/CD workflow, which AWS service would store the built artifacts before the deployment process?
AWS S3 (Simple Storage Service) would typically be used to store the built artifacts before the deployment process.
What is the benefit of linking AWS CodeCommit with AWS CodeBuild?
Linking AWS CodeCommit with AWS CodeBuild ensures continuous integration as any change committed to the repository triggers a new build in AWS CodeBuild.
Which AWS service automatically deploys any changes to your AWS Lambda function’s code or dependencies?
The AWS CodeDeploy service can automatically deploy changes to an AWS Lambda function’s code or dependencies.
What is the role of AWS CodeStar in the CI/CD workflow?
AWS CodeStar provides a unified user interface, enabling you to easily manage your software development activities in one place. It simplifies the setup of your entire development project including CI/CD pipelines.
How is AWS CodePipeline triggered to start CI/CD workflows?
AWS CodePipeline can be triggered to start CI/CD workflows in a few ways including direct integration with AWS CodeCommit, GitHub, or Amazon S3, or via AWS SDKs or CodePipeline API operations.
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