coder/docs/admin/templates/managing-templates/devcontainers/add-devcontainer.md

Add a dev container template to Coder

A Coder administrator adds a dev container-compatible template to Coder (Envbuilder). This allows the template to prompt for the developer for their dev container repository's URL as a parameter when they create their workspace. Envbuilder clones the repo and builds a container from the devcontainer.json specified in the repo.

You can create template files through the Coder dashboard, CLI, or you can choose a template from the Coder registry:

Dashboard

1. In the Coder dashboard, select Templates then Create Template.

2. Use a starter template or create a new template:

   • Starter template:

     1. Select Choose a starter template.
     2. Choose a template from the list or select Devcontainer from the sidebar to display only dev container-compatible templates.
     3. Select Use template, enter the details, then select Create template.

   • To create a new template, select From scratch and enter the templates details, then select Create template.

3. Edit the template files to fit your deployment.

CLI

1. Use the template init command to initialize your choice of image:

   coder template init --id kubernetes-devcontainer
   

   A list of available templates is shown in the templates_init reference.

2. cd into the directory and push the template to your Coder deployment:

   cd kubernetes-devcontainer && coder templates push
   

   You can also edit the files or make changes to the files before you push them to Coder.

Registry

1. Go to the Coder registry and select a dev container-compatible template.

2. Copy the files to your local device, then edit them to fit your needs.

3. Upload them to Coder through the CLI or dashboard:

   • CLI:

   coder templates push <template-name> -d <path to folder containing main.tf>
   

   • Dashboard:

   1. Create a .zip of the template files:

      • On Mac or Windows, highlight the files and then right click. A "compress" option is available through the right-click context menu.

      • To zip the files through the command line:

        zip templates.zip Dockerfile main.tf
        

   2. Select Templates.

   3. Select Create Template, then Upload template:

      

   4. Drag the .zip file into the Upload template section and fill out the details, then select Create template.

      

To set variables such as the namespace, go to the template in your Coder dashboard and select Settings from the ⋮ (vertical ellipsis) menu:

Envbuilder Terraform provider

When using the Envbuilder Terraform provider, a previously built and cached image can be reused directly, allowing dev containers to start instantaneously.

Developers can edit the devcontainer.json in their workspace to customize their development environments:

# …
{
  "features": {
      "ghcr.io/devcontainers/features/common-utils:2": {}
  }
}
# …

Example templates

Template	Description
Docker dev containers	Docker provisions a development container.
Kubernetes dev containers	Provisions a development container on the Kubernetes cluster.
Google Compute Engine dev container	Runs a development container inside a single GCP instance. It also mounts the Docker socket from the VM inside the container to enable Docker inside the workspace.
AWS EC2 dev container	Runs a development container inside a single EC2 instance. It also mounts the Docker socket from the VM inside the container to enable Docker inside the workspace.

Your template can prompt the user for a repo URL with parameters:

Dev container lifecycle scripts

The onCreateCommand, updateContentCommand, postCreateCommand, and postStartCommand lifecycle scripts are run each time the container is started. This could be used, for example, to fetch or update project dependencies before a user begins using the workspace.

Lifecycle scripts are managed by project developers.

Next steps

• Dev container security and caching