Ansible playbook for Hetzner

Find more details about this playbook (e.g., how it works and what it does) in this article.

Using this playbook

To run the Ansible playbook, use the following command:

ansible-playbook playbook.yml -i inventory/hosts.ini

You can also execute specific stages of the playbook by using tags such as hetzner_bootstrap, install_os, features, or any feature tag. For example:

ansible-playbook playbook.yml -i inventory/hosts.ini --tags "install_packages"

To enable verbose output, use the -vvv flag. For example:

ansible-playbook playbook.yml -i inventory/hosts.ini --tags "install_packages" -vvv

Important notes

Before running the Ansible playbook, you need to add a new host to inventory/hosts.ini. For example:

[hetzner_init]
bare-metal-01 hetzner_ip=1.2.3.4 server_id=1234567
[nodes]
bare-metal-01 ansible_host=1.2.3.4 ansible_user=root ansible_ssh_private_key_file=~/.ssh/id_rsa ansible_python_interpreter=/usr/bin/python3

If you decide to configure additional network interfaces, enable the setup_network feature flag in group_vars/all.yml, prepare a template for the netplan configuration and place it in the host_vars directory, naming it {{ inventory_hostname }}.yml. For example:

host_vars/bare-metal-01.yml

• The configuration file should include information on the internal and external interface settings.
• The server's ID and external IP address can be found in the Hetzner Robot Console.

In the file group_vars/all.yml, specify the user and password for the Hetzner API. You can create this user in Robot via the user menu in the upper right corner under "Settings" -> "Web service and app settings".

WARNING

Running the full playbook or the install_os stage will erase all data on the disks. Make sure the server's ID and external IP address are correct and double-check that this is the server you want to bootstrap.

Feature flags

• setup_network: Enable the additional network configuration for several network interfaces.
• set_cpu_governor_performance: By default, the CPU governor is set to the powersave mode, which can cause unexpected side effects and poor performance. Set this flag to true to switch to the performance mode.
• install_packages: Install additional packages from the given list.
• create_users: Create additional OS users, add their public keys, and set the default password with the forced policy to change it on the first login. Public keys should be added to the roles/create_users/files directory.

Planned improvements

1. Automation for joining nodes to the Kubernetes cluster.
2. Linting errors.
3. RAID creation. Currently, install_os is designed to create RAID 1 from two disks (nvme0n1 and nvme1n1). Disk names need to be dynamically determined. At this point, if there are more than two disks connected to the system, manual adjustments to roles/install_os/tasks/main.yml at line 11 are required.