{"id":185,"date":"2024-05-31T23:14:07","date_gmt":"2024-06-01T06:14:07","guid":{"rendered":"http:\/\/184.72.63.26\/?p=185"},"modified":"2024-06-17T23:19:22","modified_gmt":"2024-06-18T06:19:22","slug":"use-aws-codepipeline-ci-cd-to-automate-unit-test-and-deploy-lambda-function","status":"publish","type":"post","link":"https:\/\/www.wallacel.com\/index.php\/2024\/05\/31\/use-aws-codepipeline-ci-cd-to-automate-unit-test-and-deploy-lambda-function\/","title":{"rendered":"Use AWS CodePipeline CI\/CD to automate Unit Test and Deploy Lambda Function"},"content":{"rendered":"\n

In this guide, I will walk you through setting up a Continuous Integration and Continuous Deployment (CI\/CD) pipeline. This pipeline will automate unit testing and deploy your code to an AWS Lambda function using AWS CodePipeline, CodeBuild and CloudFormation.<\/p>\n\n\n\n

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Source Stage<\/h2>\n\n\n\n

Our journey begins with a GitHub repository, which stores our source code. Any time changes are pushed to this repository, the pipeline is automatically triggered.<\/p>\n\n\n\n

Build & Test Stage<\/h2>\n\n\n\n

Next, AWS CodeBuild steps in to compile the source code and run unit tests. Upon successful completion, the build artifacts are stored in an S3 bucket.<\/p>\n\n\n\n

Deploy Stage<\/h2>\n\n\n\n

Finally, AWS CloudFormation takes over, retrieving the artifacts (source code) from the S3 bucket and deploying the function to AWS Lambda.<\/p>\n\n\n\n

Step 1: Create Lambda Function<\/h2>\n\n\n\n

As an example, I create a simple Lambda Function that takes a city name as a parameter and returns the current temperature. To fetch the weather information, I signup for a free account at OpenWeather.org<\/a> to use their API. Following is the API call to get the weather data:<\/p>\n\n\n\n

http:\/\/api.openweathermap.org\/data\/2.5\/weather?q=city_name&appid=api_key&units=metric<\/code><\/pre>\n\n\n\n
This is my Lambda function:<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
I use the following event data to test my function and get a response that shows the function is working:<\/p>\n\n\n\n
{\n  \"city\": \"Vancouver\"\n}<\/code><\/pre>\n\n\n\n
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I create a GitHub repository and upload my code with following commands:<\/p>\n\n\n\n
git add.; git commit -m \"Add Lambda Function Python code\"; git push<\/code><\/pre>\n\n\n\n
Step 2: Create CodeBuild Project<\/h2>\n\n\n\n
Go to AWS CodeBuild console and click on Create project. To enable CodeBuild to retrieve source code from GitHub, setup a connection using OAuth and choose the source code repository. This connection allows CodeBuild to automatically fetch and build the source code whenever changes are pushed to the specified GitHub repository.<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
Since my Lambda function is written in Python and there is no Python runtime available in the standard environment options, I use a standard runtime and specify my runtime by using a buildspec file.<\/p>\n\n\n\n
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The buildspec file ensures that CodeBuild uses the specified Python runtime to build and test my Lambda function code. This file is also where I add automated unit tests. Here\u2019s how I set up my buildspec.yml<\/code> file:<\/p>\n\n\n\n
version: 0.2\nphases:\n  install:\n    runtime-versions:\n      python: 3.10   # Specify the Python version you need\n  build:\n    commands:\n      - echo Testing the Lambda functon...\n      - python -m unittest discover tests\nartifacts:\n  files:\n    - '**\/*'    # Include all files in the build output<\/code><\/pre>\n\n\n\n
Explanation:<\/h3>\n\n\n\n