CLI-based access

Estimated reading time: 2 minutes

Docker UCP secures your swarm by using role-based access control, so that only authorized users can perform changes to the cluster.

For this reason, when running docker commands on a UCP node, you need to authenticate your request with client certificates. When trying to run docker commands without a valid certificate, you get an authentication error:

$ docker ps

x509: certificate signed by unknown authority

There are two different types of client certificates:

  • Admin user certificate bundles: allow running docker commands on the Docker Engine of any node,
  • User certificate bundles: only allow running docker commands through a UCP manager node.

Download client certificates

To download a client certificate bundle, log in to the UCP web UI and navigate to your My Profile page.

In the left pane, click Client Bundles and click New Client Bundle to download the certificate bundle.

Use client certificates

Once you’ve downloaded a client certificate bundle to your local computer, you can use it to authenticate your requests.

Navigate to the directory where you downloaded the user bundle, and unzip it. Then source the env.sh script.

$ unzip ucp-bundle-dave.lauper.zip
$ eval $(<env.sh)

The env.sh script updates the DOCKER_HOST environment variable to make your local Docker CLI communicate with UCP. It also updates the DOCKER_CERT_PATH environment variables to use the client certificates that are included in the client bundle you downloaded.

Note: The bundle includes scripts for setting up Windows nodes. To set up a Windows environment, run env.cmd in an elevated command prompt, or run env.ps1 in an elevated PowerShell prompt.

From now on, when you use the Docker CLI client, it includes your client certificates as part of the request to the Docker Engine. You can now use the Docker CLI to create services, networks, volumes and other resources on a swarm that’s managed by UCP.

Download client certificates by using the REST API

You can also download client bundles by using the UCP REST API. In this example, we use curl to make the web requests to the API, and jq to parse the responses.

To install these tools on a Ubuntu distribution, you can run:

$ sudo apt-get update && apt-get install curl jq

Then you get an authentication token from UCP, and use it to download the client certificates.

# Create an environment variable with the user security token
$ AUTHTOKEN=$(curl -sk -d '{"username":"<username>","password":"<password>"}' https://<ucp-ip>/auth/login | jq -r .auth_token)

# Download the client certificate bundle
$ curl -k -H "Authorization: Bearer $AUTHTOKEN" https://<ucp-ip>/api/clientbundle -o bundle.zip

Where to go next

ucp, cli, administration