Remote Development on Kubernetes Pods (with Devcontainers)

Provision Devcontainers as Coder workspaces on Kubernetes with this example template.

Prerequisites

Infrastructure

Cluster: This template requires an existing Kubernetes cluster.

Container Image: This template uses the envbuilder image to build a Devcontainer from a devcontainer.json.

(Optional) Cache Registry: Envbuilder can utilize a Docker registry as a cache to speed up workspace builds. The envbuilder Terraform provider will check the contents of the cache to determine if a prebuilt image exists. In the case of some missing layers in the registry (partial cache miss), Envbuilder can still utilize some of the build cache from the registry.

Authentication

This template authenticates using a ~/.kube/config, if present on the server, or via built-in authentication if the Coder provisioner is running on Kubernetes with an authorized ServiceAccount. To use another authentication method, edit the template.

Architecture

Coder supports devcontainers with envbuilder, an open source project. Read more about this in Coder's documentation.

This template provisions the following resources:

Kubernetes deployment (ephemeral)
Kubernetes persistent volume claim (persistent on /workspaces)
Envbuilder cached image (optional, persistent).

This template will fetch a Git repo containing a devcontainer.json specified by the repo parameter, and builds it with envbuilder. The Git repository is cloned inside the /workspaces volume if not present. Any local changes to the Devcontainer files inside the volume will be applied when you restart the workspace. As you might suspect, any tools or files outside of /workspaces or not added as part of the Devcontainer specification are not persisted. Edit the devcontainer.json instead!

Note This template is designed to be a starting point! Edit the Terraform to extend the template to support your use case.

Caching

To speed up your builds, you can use a container registry as a cache. When creating the template, set the parameter cache_repo.

See the Envbuilder Terraform Provider Examples for a more complete example of how the provider works.

Note

We recommend using a registry cache with authentication enabled. To allow Envbuilder to authenticate with the registry cache, specify the variable cache_repo_dockerconfig_secret with the name of a Kubernetes secret in the same namespace as Coder. The secret must contain the key .dockerconfigjson.