Kubernetes in Codespaces

Setup a Kubernetes cluster using k3d running in GitHub Codespaces

Overview

This is a template that will setup a Kubernetes developer cluster using k3d in a GitHub Codespace

We use this for inner-loop Kubernetes development. Note that it is not appropriate for production use but is a great Developer Experience. Feedback calls the approach game-changing - we hope you agree!

For ideas, feature requests, and discussions, please use GitHub discussions so we can collaborate and follow up.

This Codespace is tested with zsh and oh-my-zsh.

You can connect to the Codespace with a local version of VS Code.

Please experiment and add any issues to the GitHub Discussion.

The motivation for creating and using Codespaces is highlighted by this GitHub Blog Post. "It eliminated the fragility and single-track model of local development environments, but it also gave us a powerful new point of leverage for improving GitHub’s developer experience."

Cory Wilkerson, Senior Director of Engineering at GitHub, recorded a podcast where he shared the GitHub journey to Codespaces

Join the CSE-Labs GitHub Org

You must be a member of the Microsoft OSS and CSE-Labs GitHub organizations

• If you can't open a Codespace in this repo, you need to join the GitHub org(s)
  • Instructions for joining are here
• Return to this repo after joining the org(s)

Open with Codespaces

You must be a member of the Microsoft OSS and CSE-Labs GitHub organizations

• Click the Code button on this repo
• Click the Codespaces tab
• Click New Codespace
• Choose the 4 core option

Stopping a Codespace

• Codespaces will shutdown automatically after being idle for 30 minutes

• To shutdown a codespace immediately

  • Click Codespaces in the lower left of the browser window
  • Choose Stop Current Codespace from the context menu

• You can also rebuild the container that is running your Codespace

  • Any changes in /workspaces will be retained
  • Other directories will be reset
  • Click Codespaces in the lower left of the browser window
  • Choose Rebuild Container from the context menu
  • Confirm your choice

• To delete a Codespace

  • https://github.com/codespaces
  • Use the context menu to delete the Codespace
  • Please delete your Codespace once you complete the lab
    • Creating a new Codespace only takes about 45 seconds!

Checking the k3d Cluster

• A k3d cluster is created as part of the Codespace setup

  • kic is a small CLI that we use to simplify Kubernetes development

  # check the pods
  kic pods
  

• Output from kic pods should resemble this

  
  NAMESPACE     NAME                                      READY   STATUS              RESTARTS   AGE
  kube-system   local-path-provisioner-5ff76fc89d-wfpjx   1/1     Running             0          48s
  kube-system   coredns-7448499f4d-dnjzl                  1/1     Running             0          48s
  kube-system   metrics-server-86cbb8457f-qlp8v           1/1     Running             0          48s
  logging       fluentbit-cq45s                           1/1     Running             0          32s
  kube-system   helm-install-traefik-crd-zk5gr            0/1     Completed           0          48s
  kube-system   helm-install-traefik-mbr2l                0/1     Completed           1          48s
  heartbeat     heartbeat-65978f8f88-dw9fn                1/1     Running             0          32s
  default       jumpbox                                   1/1     Running             0          32s
  imdb          imdb-79d8c756b-2p465                      1/1     Running             0          33s
  monitoring    grafana-5df456f89c-2r6cm                  1/1     Running             0          32s
  kube-system   svclb-traefik-2ks5t                       2/2     Running             0          22s
  kube-system   traefik-97b44b794-txs9h                   1/1     Running             0          22s
  heartbeat     webv-heartbeat-776cbf6fbf-jvk5x           1/1     Running             0          32s
  imdb          webv-796c76d69d-5ghnq                     1/1     Running             0          4s
  monitoring    prometheus-deployment-5c57d9b77d-tdtn2    1/1     Running             0          32s
  
  

Validate Deployment

• If you get an error, just run the command again - it will clear once the services are ready

# check endpoints
kic check all

Validating endpoints

Open curl.http

curl.http is used in conjuction with the Visual Studio Code REST Client extension.

When you open curl.http, you should see a clickable Send Request text above each of the URLs

Clicking on Send Request should open a new panel in Visual Studio Code with the response from that request like so:

Jump Box

A jump box pod is created so that you can execute commands in the cluster

• use the kj alias

  • example
    • run kj
      • Your terminal prompt will change
      • From the jumpbox terminal
      • Run http imdb.imdb.svc.cluster.local:8080/version
      • exit back to the Codespaces terminal

• use the kje alias

  • example
    • run http against the ClusterIP
      • kje http imdb.imdb.svc.cluster.local:8080/version

• Since the jumpbox is running in the cluster, we use the service name and port, not the NodePort

  • A jumpbox is great for debugging network issues

NodePorts

• Codespaces exposes ports to the local browser

• We take advantage of this by exposing NodePort on most of our K8s services

• Codespaces ports are setup in the .devcontainer/devcontainer.json file

• Exposing the ports

  // forward ports for the app
  "forwardPorts": [
    30000,
    30080,
    31080,
    32000
  ],
  

• Adding labels to the ports

  // add labels
  "portsAttributes": {
    "30000": { "label": "Prometheus" },
    "30080": { "label": "IMDb-app" },
    "31080": { "label": "Heartbeat" },
    "32000": { "label": "Grafana" },
  },
  

View IMDB App

• Click on the ports tab of the terminal window
• Click on the open in browser icon on the IMDb-App port (30080)
• This will open the imdb-app home page (Swagger) in a new browser tab

View Heartbeat

• Click on the ports tab of the terminal window
• Click on the open in browser icon on the Heartbeat port (31080)
• This will open the heartbeat home page (Swagger) in a new browser tab
  • Note that you will see page Under construction ... as heartbeat does not have a UI
  • Add version or /heartbeat/17 to the end of the URL in the browser tab

Build and deploy a local version of imdb-app

• We have a local Docker container registry running in the Codespace

  • Run docker ps to see the running images

• Build the WebAPI app from the local source code

• Push to the local Docker registry

• Deploy to local k3d cluster

• Switch back to your Codespaces tab

  # from Codespaces terminal
  
  # make and deploy a local version of imdb-app to k8s
  kic build imdb
  
  # check the app version
  # the semver will have the current date and time
  http localhost:30080/version
  

Validate deployment with k9s

To exit K9s - :q <enter>

• From the Codespace terminal window, start k9s

  • Type k9s and press enter

  • Press 0 to select all namespaces

  • Use the arrow key to select webv pod for heartbeat then press the l key to view logs from the pod

    • Notice that WebV is making a heartbeat request every 5 seconds
    • To go back, press the esc key

  • Use the arrow key to select webv pod for imdb then press the l key to view logs from the pod

    • Notice that WebV is making 10 IMDb requests per second
    • To go back, press the esc key

  • Use the arrow key to select jumpbox then press s key to open a shell in the container

    • Test the IMDb-App service from within the cluster by executing

      # httpie is a "pretty" version of curl
      # test the webv-imdb service endpoint using local DNS
      http webv.imdb.svc.cluster.local:8080/metrics
      

      • exit <enter>

  • To view other resources - press shift + : followed by the deployment type (e.g. secret, services, deployment, etc).

View Fluent Bit Logs

Fluent Bit is set to forward logs to stdout for debugging

Fluent Bit can be configured to forward to different services including Grafana Cloud or Azure Log Analytics

Fluent Bit is also installed in the Codespace to simplify debugging new configurations. Run fluent-bit --help for more details.

• Start k9s from the Codespace terminal (if it's not running from previous step)
• Press 0 to show all namespaces
• Select fluentbit pod and press enter
• Press enter again to see the logs
• Press s to Toggle AutoScroll
• Press w to Toggle Wrap
• Review logs that will be sent to Grafana when configured

To exit K9s - :q <enter>

View Prometheus Dashboard

• Click on the ports tab of the terminal window

• Click on the open in browser icon on the Prometheus port (30000)

• This will open Prometheus in a new browser tab

• From the Prometheus tab

  • Begin typing ImdbAppDuration_bucket in the Expression search
  • Click Execute
  • This will display the log table that Grafana uses for the charts

View Grafana Dashboard

• Grafana login info

  • admin
  • cse-labs

• Click on the ports tab of the terminal window

  • Click on the open in browser icon on the Grafana port (32000)
  • This will open Grafana in a new browser tab

IMDb-App dashboard is set as the default home dashboard to visualize constant load generated to the IMDB application.

Explore Grafana Dashboards

• Click on the dashboard folder General at the top (with four squares) to access the dashboard search. The dashboard search can also be opened by using the shortcut F.
• The list will show all the dashboards configured in Grafana.
• We configure two dashboards as part of the initial deployment:
  • IMDb App
  • Dotnet

Run integration and load tests

# from Codespaces terminal

# run an integration test (will generate warnings in Grafana)
kic test integration

# run a 30 second load test
kic test load

• Switch to the Grafana browser tab
• The integration test generates 400 and 404 results by design
• The requests metric will go from green to yellow to red as load increases
  • It may skip yellow
• As the test completes
  • The metric will go back to green (10 req/sec)
  • The request graph will return to normal

How Codespaces is built

Codespaces extends the use of development containers by providing a remote hosting environment. A development container is a fully-featured development environment running in a Docker container.

Developers can simply click on a button in GitHub to open a Codespace for the repo. Behind the scenes, GitHub Codespaces is:

• Starting a VM
• Shallow clone the repo in that VM. The shallow clone pulls the devcontainer.json onto the VM
• Start the development container on the VM
• Clone the repository in the development container
• Connect to the remotely hosted development container via the browser or Visual Studio Code

.devcontainer folder contains the following:

• devcontainer.json: This configuration file determines the environment for new Codespaces created for the repository by defining a development container that can include frameworks, tools, extensions, and port forwarding. For more information about the settings and properties that you can set in a devcontainer.json, see devcontainer.json reference in the Visual Studio Code documentation.

• Dockerfile: Dockerfile in .devcontainer defines a container image and installs software. You can use an existing base image by using the FROM instruction. For more information on using a Dockerfile in a dev container, see Create a development container in the Visual Studio Code documentation.

• Bash scripts: We store lifecycle scripts under the .devcontainer folder. They are the hooks that allow you to run commands at different points in the development container lifecycle which include:

  • onCreateCommand - Run when creating the container
  • postCreateCommand - Run after the container is created
  • postStartCommand - Run every time the container starts

  For more information on using Lifecycle scripts, see Codespaces lifecycle scripts.

  Note: Provide executable permissions to scripts using: chmod+ x.

Next Steps

Explore your Kubernetes in Codespaces cluster

• kic CLI
• K9s
• kubectl
• Docker

If you break your cluster, just rebuild it using

kic cluster rebuild

FAQ

• Why don't we use helm to deploy Kubernetes manifests?
  • The target audience for this repository is app developers so we chose simplicity for the Developer Experience.
  • In our daily work, we use Helm for deployments and it is installed in the Codespace should you want to use it.
• Why k3d instead of Kind?
  • We love kind! Most of our code will run unchanged in kind (except the cluster commands)
  • We had to choose one or the other as we don't have the resources to validate both
  • We chose k3d for these main reasons
    • Smaller memory footprint
    • Faster startup time
    • Secure by default
      • K3s supports the CIS Kubernetes Benchmark
    • Based on K3s which is a certified Kubernetes distro
      • Many customers run K3s on the edge as well as in CI-CD pipelines
    • Rancher provides support - including 24x7 (for a fee)
    • K3s has a vibrant community
    • K3s is a CNCF sandbox project

Engineering Docs

• Team Working Agreement
• Team Engineering Practices
• CSE Engineering Fundamentals Playbook

How to file issues and get help

This project uses GitHub Issues to track bugs and feature requests. Please search the existing issues before filing new issues to avoid duplicates. For new issues, file your bug or feature request as a new issue.

For help and questions about using this project, please open a GitHub issue.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Trademarks

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Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines.

Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.

Any use of third-party trademarks or logos are subject to those third-party's policies.