Raspberry Pi Ansible

Glenn K. Lockwood, October 2018

Introduction

This is an Ansible configuration that configures a fresh Raspbian installation on Raspberry Pi. It is intended to be run in local (pull) mode, where ansible is running on the same Raspberry Pi to be configured.

Bootstrapping on Raspbian

You will need ansible installed on the Raspberry Pi being configured. This playbook relies on Ansible 2.8 or newer, which means you can no longer use sudo apt-get install ansible. Instead, you must

$ python3 -m venv --system-site-packages ansible_env

$ source ./ansible_env/bin/activate

# Make sure that pip will install into our virtualenv
(ansible_env) $ which pip
/home/pi/src/git/rpi-ansible/ansible/bin/pip

# Install ansible and any other requirements
(ansible_env) $ pip install -r requirements.txt

Note that the Python 3.5 that ships with Debian 9.13 doesn't install pip when -m venv is used as above. It may be easier to simply use

$ pip3 install --user ansible

which pollutes your login Python environment, but is better than nothing.

Configuration

This playbook can be run on localhost or against one or more remote hosts. The former is good for a bare Raspberry Pi that was freshly provisioned using NOOBS or the like, as you don't need a second host to act as the provisioning host. The latter is the conventional way in which ansible is typically run and makes more sense if you want to configure a bunch of Raspberry Pis.

Local Mode

Edit local.yml and add the mac address of eth0 for the Raspberry Pi to configure to the macaddrs variable. Its key should be a mac address (all lower case) and the value should be the short hostname of that system. Each such entry's short hostname must match a file in the host_vars/ directory.

All modes

The contents of each file in host_vars/ is the intended configuration state for each Raspberry Pi. Look at one of the examples included to get a feel for the configurations available.

To add local users, create and edit roles/common/vars/users.yml. Follow the structure in roles/common/vars/users.yml.example. You can/should ansible-vault this file.

Running the playbook

Local Mode

Then run the playbook:

(ansible_env) $ ansible-playbook --ask-vault-pass --become --become-user root --ask-become-pass --inventory hosts ./local.yml

The playbook will self-discover its settings, then idempotently configure the Raspberry Pi.

Remote Mode

This is similar to local mode:

(ansible_env) $ ansible-playbook --ask-vault-pass --inventory hosts.remote ./remote.yml

The playbook follows the same code path.

After running the playbook

This playbook purposely requires a few manual steps after running the playbook to ensure that it does not lock you out of your Raspberry Pi.

1. While logged in as pi, sudo passwd glock (or whatever username you created) to set a password for that user. This is not required to log in as that user, but it is required to sudo as that user. You may also choose to set a password for the pi and/or root users.

2. usermod --lock pi to ensure that the default user is completely disabled.

Optional configurations

SSH host keys

This playbook can install ssh host keys. To do so,

1. Drop the appropriate ssh_host_*_key files into roles/common/files/etc/ssh/
2. Rename each file from ssh_host_*_key to ssh_host_*_key.hostname where hostname matches the hostname in roles/common/vars/main.yml to which the hostkey should be deployed
3. ansible-vault encrypt roles/common/files/etc/ssh/ssh_host_*_key.*
4. Add these files to roles/common/vars/main.yml

The format expected in roles/common/vars/main.yml is something like

---
macaddrs:
    dc:a6:32:8c:8a:53:
        hostname: "cloverdale"
        # ...
        ssh_host_key_files:
          - etc/ssh/ssh_host_rsa_key.cloverdale
          - etc/ssh/ssh_host_dsa_key.cloverdale
          - etc/ssh/ssh_host_ecdsa_key.cloverdale
          - etc/ssh/ssh_host_ed25519_key.cloverdale

Acknowledgment

I stole a lot of knowledge from https://github.com/giuaig/ansible-raspi-config/.