CI is a software development practice in which incremental code changes are made frequently and reliably. Automated build-and-test steps triggered by CI ensure that code changes being merged into the repository are reliable. The code is then delivered quickly and seamlessly as a part of the CD process.
Learn how continuous integration and deployment (CI/CD) allows professional teams to make dozens of changes while making sure everyone is coordinated and nothing is broken.
Create a complete CI/CD pipeline and experience how pushing code into a source code repository triggers tests to be performed, a container to be built, tested, and its image published into a registry, the image to be pulled from a container server and bringing your web application to life.
It's not necessary to build and run docker images on your local machine. However, if you want to do so, you need to install docker on your local machine. On a Mac, you can install docker desktop from https://www.docker.com/products/docker-desktop. On a Windows machine, you can install docker desktop from https://www.docker.com/products/docker-desktop. On a Linux machine, you can install docker from https://docs.docker.com/engine/install/. Again, it's not necessary to install docker on your local machine, up to you ...
Login to your github account and search for this repo: wolfpaulus/cicd .. cick on it.
Fork this repo to your own github account.
You can do this by clicking on the "Fork" button in the upper right corner of this page.
Keep the Repo name as is, i.e. cicd, and copy the main branch to your own repo. I.e., click on the green
"Create fork" button.
Open the Actions tab in your forked repo. Click the green button to enable workflows in your forked repo.
Still on the github website, open the forked cicd repo's settings,
(not your account settings.)
Under Actions, click on General, scroll down to "Workflow permission" and select "Read and write permissions".
This is necessary to allow the workflows to push the docker image to the github container registry.
Click on "Save".
Open your account settings (not this repo's settings). Open Developer settings (bottom of the left menu). Open Personal Access Tokens Open Tokens (classic)
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Generate a new Token (classic)
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Provide a name, e.g. CICD
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Provide a reasonable expiration
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Check:
- repo
- workflow
- write:package
- delete:packages
- read:org
- gist
Copy your personal access token now. You won’t be able to see it again!
Open PyCharm, if it opens an existing project, close the project.
On the welcome screen, click on "Get from VCS" and provide the URL to your forked repo. E.g.:
https://github.com/<Your User Name>/cicd
Click on "Clone" and wait for the project to be cloned.
If PyCharm asks to create a virtual environment, click "Create" and wait for the virtual environment to be created.
Now make a small change to the README.md file, e.g. add a new line at the top and push the change to github, like so:
Right-click on the README.md file and select "Git -> Commit File..." .
Provide a commit-msg, and click the "Commit and Push..." button.
Provide your github user name and email address and click "OK".
Click the "Push" button on the bottom right of the commit dialog.
Eventually, you will be asked for your github credentials, use the token you created above.
(Paste the token exactly as it is, including the leading "ghp_" make you no additional spaces are added)
Open your forked repo on github.com and verify that your changes have been pushed. Open the Actions tab in your forked repo. Click the green "I understand my workflows..." button.
Make another small change to the README.md file, e.g. add a new line at the top and push the change to github. Return to the Actions tab in your forked repo and verify that the tests have run and a docker image was built.
You can either push a new commit to the repo or manually trigger the workflows. To manually trigger a workflow, open the Actions tab, click on a workflow under "All workflows". Click on the "Job" on the left side of the screen and click the "Run workflow" button.
You can find your cicd docker image by clicking on the "Packages" on the main GitHub page. From a remote machine, you can pull and run the image, using the following commands in the terminal: (Docker needs to be installed and running on the remote machine.)
docker login ghcr.io -u <Your User Name> -p <Your Personal Access Token>
docker pull ghcr.io/<Your User Name>/cicd:latest```
docker run -p 8080:8080 ghcr.io/<Your User Name>/cicd:latest
This project is a simple web application that displays if a given number is odd or even. The application is written in Python and uses python's http.server, not adding additional requirements.
Unit tests are written using pytest. I.e., pytest needs to be installed to run the tests.
Two github actions are defined to run the tests and build the docker image. The docker image is run and tested before pushed to the github container registry.
From there the image can pulled and deployed automatically, for instance by running Watchtower on the server.
To run the tests locally, you need to install pytest and set the PYTHONPATH environment variable to the src directory.
The following steps show how to do this in a virtual environment:
Activate the virtual environment, e.g.
source ./venv/bin/activate or .\venv\Scripts\activate on Windows
pip install pytest
python -m pytest # or simply pytest
Open a terminal, navigate to the project directory (./cicd) and run the following commands:
python3 ./src/ws.py
Now open a browser and navigate to http://localhost:8080/ and enter a number to see if it is odd or even.
To run the application in a container, you need to have docker installed.
Open a terminal, navigate to the project directory (./cicd) and run the following commands:
docker build -t odd-even .
docker run -p 8080:8080 odd-even
Now open a browser and navigate to http://localhost:8080/ and enter a number to see if it is odd or even.
To run the tests in a container, you need to have docker installed.
Open a terminal, navigate to the project directory (./cicd) and run the following commands:
docker build -t odd-even .
docker run odd-even /cicd/healthcheck.sh
The script will exit with 0 "Health check was OK 200" if the tests pass and 1 if they fail.