Tutorial: Set up the GitLab workspaces proxy

In this tutorial, you'll learn how to set up the GitLab workspaces proxy to authenticate and authorize workspaces in your cluster.

To set up gitlab-workspaces-proxy, you're going to:

Generate TLS certificates.
Register an app on your GitLab instance.
Generate an SSH host key.
Export the GitLab URL.
Create a configuration secret.
Verify the Kubernetes resources.
Update your DNS records.

Prerequisites

An installed Ingress controller
A running Kubernetes cluster
helm 3.11.0 and later and kubectl on your local machine

Generate TLS certificates

You must generate TLS certificates for:

The domain gitlab-workspaces-proxy listens on (GITLAB_WORKSPACES_PROXY_DOMAIN).
The domain workspaces are available on (GITLAB_WORKSPACES_WILDCARD_DOMAIN).

You can generate certificates from any certificate authority.

To generate TLS certificates:

Install Certbot to enable HTTPS:
```
brew install certbot
```

Generate Let's Encrypt certificates with ACME DNS and create TXT records in your DNS provider:

export EMAIL="YOUR_EMAIL@example.dev"
export GITLAB_WORKSPACES_PROXY_DOMAIN="workspaces.example.dev"
export GITLAB_WORKSPACES_WILDCARD_DOMAIN="*.workspaces.example.dev"

certbot -d "${GITLAB_WORKSPACES_PROXY_DOMAIN}" \
  -m "${EMAIL}" \
  --config-dir ~/.certbot/config \
  --logs-dir ~/.certbot/logs \
  --work-dir ~/.certbot/work \
  --manual \
  --preferred-challenges dns certonly

certbot -d "${GITLAB_WORKSPACES_WILDCARD_DOMAIN}" \
  -m "${EMAIL}" \
  --config-dir ~/.certbot/config \
  --logs-dir ~/.certbot/logs \
  --work-dir ~/.certbot/work \
  --manual \
  --preferred-challenges dns certonly

Update the following environment variables with the certificate directories from the output:

export WORKSPACES_DOMAIN_CERT="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_PROXY_DOMAIN}/fullchain.pem"
export WORKSPACES_DOMAIN_KEY="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_PROXY_DOMAIN}/privkey.pem"
export WILDCARD_DOMAIN_CERT="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_WILDCARD_DOMAIN}/fullchain.pem"
export WILDCARD_DOMAIN_KEY="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_WILDCARD_DOMAIN}/privkey.pem"

The certbot command might create a different path for the wildcard domain by using the proxy domain and a -0001 prefix:

export WORKSPACES_DOMAIN_CERT="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_PROXY_DOMAIN}/fullchain.pem"
export WORKSPACES_DOMAIN_KEY="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_PROXY_DOMAIN}/privkey.pem"
export WILDCARD_DOMAIN_CERT="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_PROXY_DOMAIN}-0001/fullchain.pem"
export WILDCARD_DOMAIN_KEY="${HOME}/.certbot/config/live/${GITLAB_WORKSPACES_PROXY_DOMAIN}-0001/privkey.pem"

Now that you've generated the certificates, it's time to register an app on your GitLab instance.

Register an app on your GitLab instance

To register an app on your GitLab instance:

Configure GitLab as an OAuth 2.0 identity provider.
Set the redirect URI to https://${GITLAB_WORKSPACES_PROXY_DOMAIN}/auth/callback.
Set the scopes to api, read_user, openid, and profile.

Export your CLIENT_ID, CLIENT_SECRET, and REDIRECT_URI:

export CLIENT_ID="your_application_id"
export CLIENT_SECRET="your_application_secret"
export REDIRECT_URI="https://${GITLAB_WORKSPACES_PROXY_DOMAIN}/auth/callback"

Store the client ID and generated secret in a safe place (for example, 1Password).

Next, you'll generate an SSH host key and export the GitLab URL.

Generate an SSH host key

To generate an RSA key, run this command:

ssh-keygen -f ssh-host-key -N '' -t rsa
export SSH_HOST_KEY=$(pwd)/ssh-host-key

You can also generate an ECDSA key instead.

Export the GitLab URL

To export the GITLAB_URL environment variable, run this command:

export GITLAB_URL="https://gitlab.com"

Next, you'll create a configuration secret for the proxy.

Create a configuration secret

To create a configuration secret for the proxy:

Create a signing key and store the key in a safe place (for example, 1Password).

Export your SIGNING_KEY:

export SIGNING_KEY="make_up_a_random_key_consisting_of_letters_numbers_and_special_chars"

Add the helm repository:

helm repo add gitlab-workspaces-proxy \
  https://gitlab.com/api/v4/projects/gitlab-org%2fremote-development%2fgitlab-workspaces-proxy/packages/helm/devel

Modify the ingress.className parameter if you're using a different Ingress class:

helm repo update

helm upgrade --install gitlab-workspaces-proxy \
  gitlab-workspaces-proxy/gitlab-workspaces-proxy \
  --version 0.1.13 \
  --namespace=gitlab-workspaces \
  --create-namespace \
  --set="auth.client_id=${CLIENT_ID}" \
  --set="auth.client_secret=${CLIENT_SECRET}" \
  --set="auth.host=${GITLAB_URL}" \
  --set="auth.redirect_uri=${REDIRECT_URI}" \
  --set="auth.signing_key=${SIGNING_KEY}" \
  --set="ingress.host.workspaceDomain=${GITLAB_WORKSPACES_PROXY_DOMAIN}" \
  --set="ingress.host.wildcardDomain=${GITLAB_WORKSPACES_WILDCARD_DOMAIN}" \
  --set="ingress.tls.workspaceDomainCert=$(cat ${WORKSPACES_DOMAIN_CERT})" \
  --set="ingress.tls.workspaceDomainKey=$(cat ${WORKSPACES_DOMAIN_KEY})" \
  --set="ingress.tls.wildcardDomainCert=$(cat ${WILDCARD_DOMAIN_CERT})" \
  --set="ingress.tls.wildcardDomainKey=$(cat ${WILDCARD_DOMAIN_KEY})" \
  --set="ssh.host_key=$(cat ${SSH_HOST_KEY})" \
  --set="ingress.className=nginx"

NOTE: You might have to renew your certificates. For example, Let's Encrypt certificates are valid for three months by default. When you get new certificates, run the previous helm command again to update the certificates.

Let's now verify the Kubernetes resources.

Verify the Kubernetes resources

Verify the following Kubernetes resources:

The configuration secret:

kubectl -n gitlab-workspaces get secret gitlab-workspaces-proxy  -o=go-template='{{index .data "config.yaml"}}' | base64 -d

The Ingress class for the gitlab-workspaces namespace:
```
kubectl -n gitlab-workspaces get ingress
```
If you deploy the GitLab Helm chart to any namespace other than gitlab-workspaces, update the namespace in the GitLab agent configuration:
```
remote_development:
  gitlab_workspaces_proxy:
    namespace: "<custom-gitlab-workspaces-proxy-namespace>"
```

Verify the pods are running:
```
kubectl -n gitlab-workspaces get pods
```

You can now start updating your DNS records.

Update your DNS records

To update your DNS records:

Point ${GITLAB_WORKSPACES_PROXY_DOMAIN} and ${GITLAB_WORKSPACES_WILDCARD_DOMAIN} to the load balancer exposed by the Ingress controller.
From a terminal, run this command to check if gitlab-workspaces-proxy is accessible:
```
curl --verbose --location ${GITLAB_WORKSPACES_PROXY_DOMAIN}
```
This command returns a 400 Bad Request error until you create a workspace in GitLab.
From another terminal, run this command:
```
kubectl -n gitlab-workspaces logs -f -l app.kubernetes.io/name=gitlab-workspaces-proxy
```
The logs show a could not find upstream workspace upstream not found error.

You're all set! You can now use the GitLab workspaces proxy to authenticate and authorize workspaces in your cluster.