test-mcp-glama

--- title: "Development Guide" linkTitle: "Development Guide" weight: 80 description: > Set up a Karpenter development environment --- ## Dependencies The following tools are required for contributing to the Karpenter project. | Package | Version | Install | | ------------------------------------------------------------------ | -------- | ---------------------------------------------- | | [go](https://golang.org/dl/) | v1.19+ | [Instructions](https://golang.org/doc/install) | | [kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) | | `brew install kubectl` | | [helm](https://helm.sh/docs/intro/install/) | | `brew install helm` | | Other tools | | `make toolchain` | ## Developing ### Setup / Teardown Based on how you are running your Kubernetes cluster, follow the [Environment specific setup](#environment-specific-setup) to configure your environment before you continue. You can choose to either run the Karpenter controller locally on your machine, pointing to the Kubernetes cluster specified in your `~/.kube/config` or inside the Kubernetes cluster specified in your `~/.kube/config` deployed with [Helm](https://helm.sh/). #### Locally Once you have your environment set up, run the following commands to run the Karpenter Go binary against the Kubernetes cluster specified in your `~/.kube/config` ```bash make run ``` #### Inside a Kubernetes Cluster Once you have your environment set up, to install Karpenter in the Kubernetes cluster specified in your `~/.kube/config` run the following commands. ```bash make apply # Install Karpenter make delete # Uninstall Karpenter ``` ### Developer Loop * Make sure dependencies are installed * Run `make codegen` to make sure yaml manifests are generated (requires a working set of AWS credentials, see [Specifying Credentials](https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/configuring-sdk.html#specifying-credentials)) * Run `make toolchain` to install cli tools for building and testing the project * You will need a personal development image repository (e.g. ECR) * Make sure you have valid credentials to your development repository. * `$KO_DOCKER_REPO` must point to your development repository * Your cluster must have permissions to read from the repository ### Build and Deploy *Note: these commands do not rely on each other and may be executed independently* ```bash make apply # quickly deploy changes to your cluster make presubmit # run codegen, lint, and tests ``` If you are only interested in building the Karpenter images and not deploying the updated release to your cluster immediately with Helm, you can run the following: ```bash make image # build and push the karpenter images ``` *Note: that this will produce a build with the version of https://github.com/kubernetes-sigs/karpenter in your local filesystem. You can test out changes made in https://github.com/kubernetes-sigs/karpenter by replacing the dependency of https://github.com/aws/karpenter-provider-aws/. For local changes, replace `$PATH_TO_KUBERNETES_SIGS_KARPENTER` with the relative or absolute path and run: ```bash go mod edit -replace sigs.k8s.io/karpenter=$PATH_TO_KUBERNETES_SIGS_KARPENTER ``` Then you can build your image using the previous steps. ### Publishing Images Only If you only need to build and publish an image to a container registry, run the following: ```bash make image # build and push the karpenter images ``` You can test out changes made in https://github.com/kubernetes-sigs/karpenter by replacing the dependency of https://github.com/aws/karpenter-provider-aws/. For local changes, replace `$PATH_TO_KUBERNETES_SIGS_KARPENTER` with the relative or absolute path and run: ```bash go mod edit -replace sigs.k8s.io/karpenter=$PATH_TO_KUBERNETES_SIGS_KARPENTER ``` Then you can build your image using the previous steps. *Note: you need to commit the go.mod changes before running `make image` for the changes to be picked up. ### Testing ```bash make test # E2E correctness tests ``` ### Change Log Level By default, `make apply` will set the log level to debug. You can change the log level by setting the log level in your Helm values. ```bash --set logLevel=debug ``` ### Debugging Metrics OSX: ```bash open http://localhost:8080/metrics && kubectl port-forward service/karpenter -n kube-system 8080 ``` Linux: ```bash gio open http://localhost:8080/metrics && kubectl port-forward service/karpenter -n karpenter 8080 ``` ### Tailing Logs While you can tail Karpenter's logs with kubectl, there's a number of tools out there that enhance the experience. We recommend [Stern](https://pkg.go.dev/github.com/planetscale/stern#section-readme): ```bash stern -n karpenter -l app.kubernetes.io/name=karpenter ``` ## Environment specific setup ### AWS For local development on Karpenter you will need a Docker repo which can manage your images for Karpenter components. You can use the following command to provision an ECR repository. We recommend using a single "dev" repository for development across multiple projects, and to use specific image hashes instead of image tags. ```bash aws ecr create-repository \ --repository-name dev \ --image-scanning-configuration scanOnPush=true \ --region "${AWS_DEFAULT_REGION}" ``` Once you have your ECR repository provisioned, configure your Docker daemon to authenticate with your newly created repository. ```bash export KO_DOCKER_REPO="${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_DEFAULT_REGION}.amazonaws.com/dev" aws ecr get-login-password --region "${AWS_DEFAULT_REGION}" | docker login --username AWS --password-stdin "${KO_DOCKER_REPO}" ``` ## Profiling Karpenter exposes a pprof endpoint on its metrics port when [profiling]({{< relref "../reference/settings" >}}) is enabled. Learn about profiling with pprof: https://jvns.ca/blog/2017/09/24/profiling-go-with-pprof/ ### Prerequisites ``` brew install graphviz go install github.com/google/pprof@latest ``` ### Get a profile ``` # Connect to the metrics endpoint kubectl port-forward service/karpenter -n karpenter 8080 open http://localhost:8080/debug/pprof/ # Visualize the memory go tool pprof -http 0.0.0.0:9000 localhost:8080/debug/pprof/heap # Visualize CPU go tool pprof -http 0.0.0.0:9000 "localhost:8080/debug/pprof/profile?seconds=60" ```