Kubernetes Development Environment

A Kubernetes development environment (KuDE) isolated to install, develop and tests Kubernetes from the Github source code, using a Vagrant Box. This Vagrant Box or Environment is for developers contributing the Kubernetes project.

Using a Kubernetes development environment using a Vagrant Box allows to:

1. Automate the provisioning process, ensuring to have the same environment every time it is re-created
2. Destroy the environment when it's not in use, to release resources. The environment will be exactly the same the next time it's created
3. Use the same operative system (Ubuntu) and configuration by all the developers
4. Use the IDE of our preference on your own computer
5. Use the environment only to build and test your changes. You can turn it up or down whenever you want.

• Kubernetes Development Environment
  • Forking
  • Requirements
  • Quick Install
  • Build your own environment
  • Git workflow
  • Build Kubernetes
  • Testing Kubernetes
  • Alternatives
  • Credits

Forking

The first step to contribute to Kubernetes is to fork the Kubernetes projects on your Github account. Go to each of te following projects and click on the Fork button in the top-right corner.

• Kubernetes code: https://github.com/kubernetes/kubernetes
• Kubernetes Website and Documentation: https://github.com/kubernetes/website
• Kubernetes Testing Infrastructure: https://github.com/kubernetes/test-infra

To save time provisioning the environment, it's recommended to clone the forked Kubernetes projects mentioned above into the directory ./shared_folder/k8s.io. Like this:

mkdir -p shared_folder/k8s.io
cd shared_folder/k8s.io

git clone https://github.com/<github_username>/kubernetes
git clone https://github.com/<github_username>/website
git clone https://github.com/<github_username>/test-infra

Requirements

The requirements on any operative system are:

• Virtual Box and the Extension Pack version 6 or higher
• Vagrant version 2.2 or higher

Specifically on macOS X, you can install everything using brew executing this:

brew install virtualbox virtualbox-extension-pack
brew install vagrant

On Ubuntu, you need nothing if you don't want an isolated environment.

Quick Install

Having forked the Kubernetes projects and installed all the requirements for an isolated environment you can have the Kubernetes Development Environment following these instructions:

1. Create a directory to be use as workspace. Example: ./kude
2. Export the environment variable GITHUB_USER with your Github username or organization name.
3. To save time provisioning the environment, it's recommended to clone the forked Kubernetes projects mentioned above into the directory ./kude/shared_folder/k8s.io.
4. Download the Vagrantfile either from here or using curl. You can also clone the repo but the Vagrantfile is all you need.
5. Execute vagrant up to provision the environment
6. Use your favorite IDE to open the Kubernetes projects, and to follow the Git workflow explained below.
7. Execute vagrant ssh to login to the Vagrant box
8. If you don't need the environment and want to release resources, execute vagrant destroy

Or, executing on a terminal the following commands:

mkdir -p ./kude/shared_folder/k8s.io

export GITHUB_USER=johandry

cd ./kude
curl -fsL https://raw.githubusercontent.com/johandry/kube-dev-env/main/Vagrantfile

cd ./shared_folder/k8s.io
git clone https://github.com/${GITHUB_USER}/kubernetes
git clone https://github.com/${GITHUB_USER}/website
git clone https://github.com/${GITHUB_USER}/test-infra

vagrant up

vagrant ssh

Build your own environment

1. Clone this repository or download just the Vagranfile, then modify the Vagrantfile. The main sections in the file are:

   • Parameters: They are self-descriptive variables located at the top of the file.
   • Setup/Provisioning Script: It is located after the parameters in the variable PROVISION_NODE. These are all the shell instructions to execute to setup or provisioning the vagrant box instance or node when it boot or when you execute vagrant up.
     • Try to make it idempotent.
     • Exit with non-zero when a validation fail
     • All these instructions are executed as root.
   • Network Settings: It is the last section inside teh block Vagrant.configure ... end. This block contain Vagrant instructions to setup the node. You can find information on the Vagrant Documentation.

2. Export the following environment variables:

   • GITHUB_USER: Your Github username or organization where you forked the Kubernetes projects. The Github URL should be like: github.com/{GITHUB_USERNAME}
   • FULLNAME: (Optional) Your full name like it is assigned to your Github user. It's used to configure git and it's used for your commits. If not provided, the script will get it using the git config command.
   • EMAIL: (Optional) Your email address like it is assigned to your Github user. It's used to configure git and it's used for your commits. If not provided, the script will get it using the git config command.

3. Execute the following instructions, it includes the download of the Vagrantfile, and the export of the above variables:

   mkdir -p kude/shared_folder
   cd kude
   curl -fsL https://raw.githubusercontent.com/johandry/kube-dev-env/main/Vagrantfile
   
   export GITHUB_USER=johandry
   
   vagrant up
   
   cd shared_folder

To test the environment, login into the Vagrant box and verify you have all the important requirements, or execute test.sh, like this:

vagrant ssh

./test.sh

If something fail in your build, you may want to cleanup everything and start over.

vagrant destroy

Git workflow

You must sign the Contributor License Agreement in order to contribute.

1. Go to https://github.com/kubernetes/kubernetes/issues to find issues to work on.
2. Take ownership of the issue. Make a comment on the issue you found using the tag #dibs or I would like to work on this.
3. Sync your fork's master.
4. Create a feature branch and begin work.
5. Sync as you work and iterate.
6. Pull request back to github.com/kubernetes/kubernetes
7. Go to step 5 until it's finished and accepted.
8. Merge.

Some important comments:

• Don't by shy, ask if you have questions
• If you are not ready to fix the issue, tag it as #investigating. You will not be assigned but will let others know you might call it as #dibs

You can find more information about this process in the CONTRIBUTING document of each Kubernetes project or SIG.

You can work from your computer, on whatever operative system you are, on the directory kude/shared_folder/k8s.io/. This directory is shared in your Vagrant box or development environment on the directory ~/shared_folder/k8s.io

Build Kubernetes

To build Kubernetes login to the Vagrant box and execute make, like this:

vagrant ssh
sudo make all

When you use vagrant ssh you login as the user vagrant, so it's required to use sudo when executing make.

You can also use the parameter WHAT to build just one package or executable, like this:

make WHAT=cmd/kubelet

Other useful Makefile rules are:

• clean: remove built binaries
• release: generate a release
• release-skip-tests: generate a release without running tests
• help: print all the rules

Example:

sudo make clean
sudo make release-skip-tests WHAT=cmd/kubelet

Testing Kubernetes

It's required to run the tests before committing any code change, depending of the change is the test you'd like to execute.

The tests are also executed using make using the following rules (don't forget to use sudo):

• verify: Verification tests. Required before pushing a PR
• test: Unit tests. You can use the parameter WHAT to test a package. Example: WHAT=./pkg/api/pod
• test-integration: Integration tests. You can use the parameter WHAT to test an existing integration tests. Example: WHAT=./test/integration/kubelet

You can also use the parameter GOFLAGS="-v" to tests in verbose mode. For example:

sudo make test-integration WHAT=./test/integration/pods GOFLAGS="-v"

Alternatives

The alternatives to this project would be:

• KinD which uses Docker instead of Virtual Box. KinD may consume less resources than KuDE and may provision the environment quicker (Containers vs VMs).
• VM on a Cloud can be setup using the same provisioning script but requires access to internet and will cost you. However, the performance may be better as you are not consuming your computer resources.

Credits

Thanks to Mike Brown for the mentoring and instructions to setup a VM to contribute to Kubernetes projects. The process explained here are from his repo and the Kubernetes project repos.