14. CI/CD (Back end)

jicoing

jicoing

Posted on January 8, 2021

14. CI/CD (Back end)

After setting up the git repository for my backend infrastructure (read more), it was time to automate the stack deployment as a CI/CD
pipeline for my website. I don't claim any expertise in this matter, however this article guided me.

Git: https://github.com/jicoing/git-komlalebu-sam

Git Actions

GitHub Actions makes it easy to automate all your software workflows and deploy your code right from GitHub.

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Github actions integrates with SAM and deploys my application stack in AWS from my repository code. Rough process diagram shown below:

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Action

After a lot of search I finally found a git action (Refer) that worked for me! It integrated with my template.yml and deployed the stack after a few configurations to the files. So I went ahead and created my own action after learning.

  • I setup my .git/actions/sam/package folder as below. This particular folder includes three files action.yaml, a dockerfile and a entry-point script for the dockerfile.

Tree:

git-komlalebu-sam
┣ 📂.github
┃ ┣ 📂actions
┃ ┃ ┗ 📂sam
┃ ┃ ┃ ┗ 📂package
┃ ┃ ┃ ┃ ┣ 📜action.yml
┃ ┃ ┃ ┃ ┣ 📜Dockerfile
┃ ┃ ┃ ┃ ┗ 📜entrypoint.sh
┃ ┗ 📂workflows
┃ ┃ ┗ 📜ci.yml
┣ 📂komla_function
┃ ┣ 📜app.py
┃ ┗ 📜init.py
┣ 📂tests
┃ ┣ 📜test_handler.py
┃ ┗ 📜init.py
┣ 📜README.md
┣ 📜requirements.txt
┗ 📜template.yaml

ci.yml

Let’s take a look at ci.yml.

  • The action has two jobs test and deploy. test - checks the integrity of my lambda function. deploy - deploys the entire SAM stack in AWS and needs test to be successful as a dependency. The workflow is triggered on every push to the repository.
            jobs:
              test:
              delpoy:
                    needs:test
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Test job :
The test job uses ubuntu-latest image. Installs python 3. Uses two standard actions in here - actions/checkout@v1 and actions/setup-python@v1. Installs dependencies such as pip and installs the dependencies from requirements.txt file we generated during our local testing (read more). Then it runs the test using pytest.

Deploy job :
Once the test job is successful, only then deploy job starts.
The jobs determine the actions that take place during the workflow, and in what order. The job uses ubuntu-latest image. The uses statement defines a particular action that we want to use. There is a standard action in here - actions/checkout@v1 and uses ./.github/actions/sam/package as the path to my action files.

  • The workflow uses files present in

                         ./.github/actions/sam/package
    

    📂actions
    ┗ 📂sam
    ┗ 📂package
    ┣ 📜action.yml
    ┣ 📜Dockerfile
    ┗ 📜entrypoint.sh

action.yml

The action.yaml file details metadata about the particular action. It uses the image defined in Dockerfile.

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Dockerfile

I configure my dockerfile to build a docker image alpine:latest and run the GLIBC_VER=2.31-r0' environment on it and setup awscliv2 on it. I had to adds glibc and then removes some stuff.
(Refer).
Copy the code file from my action repository to the filesystem path / of the container COPY entrypoint.sh /entrypoint.sh(Refer). However, I was facing continuous Permission denied exception so had to add the below command:
RUN ["chmod", "+x", "/entrypoint.sh"]. (Refer).

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entrypoint.sh

Most of the work is done by this file in the docker image.
It is the same code as used in this action (Refer - falnyr/aws-sam-deploy-action). The script basically configure an AWS profile with my credentials, and packages and deploys the SAM template I developed previously in template.yml file (read more).

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Secrets

The below parameters have
been passed as environment variables for security purposes.

AWS_ACCESS_KEY_ID
AWS_DEPLOY_BUCKET
AWS_SECRET_ACCESS_KEY

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git push.

CMD

             C:\Users\USER_NAME\git-komlalebu-sam>git add .
             C:\Users\USER_NAME\git-komlalebu-sam>git commit -m master
             C:\Users\USER_NAME\git-komlalebu-sam>git push origin master
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Workflow - Github Actions.

Completion status of the two jobs.

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AWS Cloudformation stack creation events.

The stack primarily consists of an API, a lambda function and a DynamoDB table.

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💖 💪 🙅 🚩
jicoing
jicoing

Posted on January 8, 2021

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