Freifunk Stuttgart Ansible

Setup

Install ansible

Install ansible from your distribution or use a virtualenv and install from pip:

1. Create virtualenv: python3 -m venv my-venv-directory
2. Enter virtualenv: source my-venv-directory/bin/activate
3. Install ansible: pip install ansible

Then, install requirements from Ansible Galaxy:

LC_ALL=C.UTF-8 ansible-galaxy install -r requirements.yml

Using nix

Use nix-shell or nix develop to use ansible.

Update to newer nixpkgs version (check functionality and add a commit afterwards):

nix flake update

Using direnv

Run mkdir .direnv && direnv allow . to enable direnv integration with nix flakes.

SSH Aliases

Some hosts are only reachable through a jumphost, e.g. Containers or VMs on a proxmox. To access them, this playbook assumes you have configured an SSH alias in your ssh_config (~/.ssh/config) like so:

Host *.ffs03
    User root
    ProxyCommand ssh ffs03 -W 10.0.3.$(( $(echo %n | sed -e 's/.ffs03//') - 3000 )):22

Usage

To deploy everything everywhere:

LC_ALL=C.UTF-8 ansible-playbook -v -i inventory/ all.yml

To deploy everything on a single host

LC_ALL=C.UTF-8 ansible-playbook -v -i inventory/test --limit example.com all.yml

where example.com denotes the hostname as defined in the inventory directory.

Roles

Users

Deploys user accounts on systems and deploys public keys.

The user database

The idea is to maintain a global user database in group_vars/all. For each user, we store the UID and a list of public keys there. Example entry for a user named johndoe with UID 1234 and a public key:

user_database:
  johndoe:
    uid: 1234
    pubkeys:
      - "ssh-rsa ... john@doe"

Creating user accounts

Note that this doesn't create the user anywhere.

You can use a host var or a group var to actually create users.

Creating accounts on hosts

To create a user on a specific host, define the variable users in host_vars

For example adding this to host_vars/example.com/users:

users:
  - johndoe

will deploy the johndoe user as defined in the user_database above on example.com.

Creating accounts on groups

This can be a bit annoying if you just want to grant a group of people access to a bunch of hosts in a group. To grant a user access to a group of hosts, define the variable users_group in group_vars.

For example adding this to group_vars/dc01:

users_group:
  - johndoe

will deploy the johndoe user as defined in the user_database above on all hosts in the group dc01.

Deploying pubkeys for the root user

Pubkeys defined in the user_database can also be deployed for the root user.

Deploying pubkeys for the root user on hosts

This is achieved by adding a user's name to the users_root list. For example adding this to host_vars/example.com/users:

users_root:
  - johndoe

will deploy all pubkeys defined in the user_database for johndoe in the root account on host `example.com.

Deploying pubkeys for the root user on groups

This is achieved by adding a user's name to the users_root_group list. For example adding this to group_vars/dc01:

users_root_group:
  - johndoe

will deploy all pubkeys defined in the user_database for johndoe in the root account on all hosts in group dc01.

DHCP Server

We support up to 4 DHCP servers in our network. The config is generated using (FfsConfigGenerator)[https://github.com/freifunk-stuttgart/FfsConfigGenerator], which contains the IP ranges of all our segments.

The range served by a DHCP sever (the pool in kea speech) is determined by the instance number of the DHCP server. Set it in the dhcp_server_instance variable. Valid values are 1-4.