Registering Ubuntu 18.04 Clients

This section contains information about registering Salt clients running Ubuntu 18.04 LTS operating systems.

Uyuni supports Ubuntu 18.04 LTS clients using Salt.

Ubuntu is supported for Salt clients only. Traditional clients are not supported.

Bootstrapping is supported for starting Ubuntu clients and performing initial state runs such as setting repositories and performing profile updates. However, the root user on Ubuntu is disabled by default, so to use bootstrapping, you require an existing user with sudo privileges for Python.

Canonical does not endorse or support Uyuni.

1. Add Software Channels

Before you register Ubuntu clients to your Uyuni Server, you need to add the required software channels, and synchronize them.

In the following section, descriptions often default to the x86_64 architecture. Replace it with other architectures if appropriate.

The channels you need for this procedure are:

Table 1. Ubuntu Channels - CLI
OS Version Ubuntu 18.04

Base Channel

ubuntu-1804-pool-amd64-uyuni

Main Channel

ubuntu-1804-amd64-main-uyuni

Updates Channel

ubuntu-1804-amd64-main-updates-uyuni

Security Channel

ubuntu-1804-amd64-main-security-uyuni

Universe Channel

ubuntu-1804-amd64-universe-uyuni

Universe Updates Channel

ubuntu-1804-amd64-universe-updates-uyuni

Universe Security Updates Channel

ubuntu-1804-amd64-universe-security-uyuni

Client Channel

ubuntu-1804-amd64-uyuni-client
Procedure: Adding Software Channels at the Command Prompt

  1. At the command prompt on the Uyuni Server, as root, use the spacewalk-common-channels command to add the appropriate channels:

    spacewalk-common-channels \
<base_channel_label> \
<child_channel_label_1> \
<child_channel_label_2> \
... <child_channel_label_n>

  2. If automatic synchronization is turned off, synchronize the channels:

    spacewalk-repo-sync -p <base_channel_label>

  3. Ensure the synchronization is complete before continuing.

You need all the new channels fully synchronized, including Universe (Universe contains important dependencies for Salt), before bootstrapping any Ubuntu client.

2. Check Synchronization Status

Procedure: Checking Synchronization Progress from the Web UI

  1. In the Uyuni Web UI, navigate to Software  Manage  Channels, then click the channel associated to the repository.

  2. Navigate to the Repositories tab, then click Sync and check Sync Status.

Procedure: Checking Synchronization Progress from the Command Prompt

  1. At the command prompt on the Uyuni Server, as root, use the tail command to check the synchronization log file:

    tail -f /var/log/rhn/reposync/<channel-label>.log

  2. Each child channel generates its own log during the synchronization progress. You need to check all the base and child channel log files to be sure that the synchronization is complete.

Ubuntu channels can be very large. Synchronization can sometimes take several hours.

3. Manage GPG Keys

Clients use GPG keys to check the authenticity of software packages before they are installed. Only trusted software can be installed on clients.

Trusting a GPG key is important for security on clients. It is the task of the administrator to decide which keys are needed and can be trusted. Because a software channel cannot be used when the GPG key is not trusted, the decision of assigning a channel to a client depends on the decision of trusting the key.

For more information about GPG keys, see GPG Keys.

4. Root Access

The root user on Ubuntu is disabled by default for SSH access.

To be able to onboard using a regular user, you need to edit the sudoers file.

This issue happens with self-installed versions of Ubuntu. If the default user has been granted administrative privileges during installation time, a password is requiered to perform privilege escalation using sudo. With cloud instances this does not happen because cloud-init automatically creates a file under /etc/sudoers.d and grants privilege escalation through sudo without the need for a password.
Procedure: Granting Root User Access

  1. On the client, edit the sudoers file:

    sudo visudo

    Grant sudo access to the user by adding this line at the end of the sudoers file. Replace <user> with the name of the user that is bootstrapping the client in the Web UI:

    <user>  ALL=NOPASSWD: /usr/bin/python, /usr/bin/python2, /usr/bin/python3, /var/tmp/venv-salt-minion/bin/python

This procedure grants root access without requiring a password, which is required for registering the client. When the client is successfully installed it runs with root privileges, so the access is no longer required. We recommend that you remove the line from the sudoers file after the client has been successfully installed.

5. Register Clients

To register your clients, you need a bootstrap repository. By default, bootstrap repositories are automatically created, and regenerated daily for all synchronized products. You can manually create the bootstrap repository from the command prompt, using this command:

mgr-create-bootstrap-repo

For more information on registering your clients, see Client Registration.