Terraform Modules | Coder Docs

Terraform Modules

To reuse code across different Coder templates, such as common scripts or resource definitions, we suggest using Terraform Modules.

You can store these modules externally from your Coder deployment, like in a git repository or a Terraform registry. This example shows how to reference a module from your template:

data "coder_workspace" "me" {}

module "coder-base" {
  source = "github.com/my-organization/coder-base"

  # Modules take in variables and can provision infrastructure
  vpc_name            = "devex-3"
  subnet_tags         = { "name": data.coder_workspace.me.name }
  code_server_version = 4.14.1
}

resource "coder_agent" "dev" {
  # Modules can provide outputs, such as helper scripts
  startup_script=<<EOF
  #!/bin/sh
  ${module.coder-base.code_server_install_command}
  EOF
}

Learn more about creating modules and module sources in the Terraform documentation.

Coder modules

Coder publishes plenty of modules that can be used to simplify some common tasks across templates. Some of the modules we publish are,

For a full list of available modules please check Coder module registry.

Offline installations

In offline and restricted deploymnets, there are 2 ways to fetch modules.

Artifactory
Private git repository

Artifactory

Air gapped users can clone the coder/modules repo and publish a local terraform module repository to resolve modules via Artifactory.

Create a local-terraform-repository with name coder-modules-local
Create a virtual repository with name tf

Follow the below instructions to publish coder modules to Artifactory

git clone https://github.com/coder/modules
cd modules
jf tfc
jf tf p --namespace="coder" --provider="coder" --tag="1.0.0"

Generate a token with access to the tf repo and set an ENV variable TF_TOKEN_example.jfrog.io="XXXXXXXXXXXXXXX" on the Coder provisioner.

Create a file .terraformrc with following content and mount at /home/coder/.terraformrc within the Coder provisioner.

provider_installation {
  direct {
      exclude = ["registry.terraform.io/*/*"]
  }
  network_mirror {
      url = "https://example.jfrog.io/artifactory/api/terraform/tf/providers/"
  }
}

Update module source as,

module "module-name" {
  source = "https://example.jfrog.io/tf__coder/module-name/coder"
  version = "1.0.0"
  agent_id = coder_agent.example.id
  ...
}

Do not forget to replace example.jfrog.io with your Artifactory URL

Based on the instructions here.

Example template

We have an example template here that uses our JFrog Docker template as the underlying module.

Private git repository

If you are importing a module from a private git repository, the Coder server or provisioner needs git credentials. Since this token will only be used for cloning your repositories with modules, it is best to create a token with access limited to the repository and no extra permissions. In GitHub, you can generate a fine-grained token with read only access to the necessary repos.

If you are running Coder on a VM, make sure that you have git installed and the coder user has access to the following files:

# /home/coder/.gitconfig
[credential]
  helper = store

# /home/coder/.git-credentials

# GitHub example:
https://your-github-username:[email protected]

If you are running Coder on Docker or Kubernetes, git is pre-installed in the Coder image. However, you still need to mount credentials. This can be done via a Docker volume mount or Kubernetes secrets.

Passing git credentials in Kubernetes

First, create a .gitconfig and .git-credentials file on your local machine. You might want to do this in a temporary directory to avoid conflicting with your own git credentials.

Next, create the secret in Kubernetes. Be sure to do this in the same namespace that Coder is installed in.

export NAMESPACE=coder
kubectl apply -f - <<EOF
apiVersion: v1
kind: Secret
metadata:
  name: git-secrets
  namespace: $NAMESPACE
type: Opaque
data:
  .gitconfig: $(cat .gitconfig | base64 | tr -d '\n')
  .git-credentials: $(cat .git-credentials | base64 | tr -d '\n')
EOF

Then, modify Coder's Helm values to mount the secret.

coder:
  volumes:
    - name: git-secrets
      secret:
        secretName: git-secrets
  volumeMounts:
    - name: git-secrets
      mountPath: "/home/coder/.gitconfig"
      subPath: .gitconfig
      readOnly: true
    - name: git-secrets
      mountPath: "/home/coder/.git-credentials"
      subPath: .git-credentials
      readOnly: true

Next steps

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