kernel.cafe automation (alpha)

Adding a node

Adding a node involves 3 steps:

• Create a barista user with sudo privileges, to be used by ansible
• (Optional) Install kconfsync, which will automatically backup system config files to GitHub, omitting keys and passwords.

Automatic

This will run the setup steps automatically on some platforms (Linux, macOS). It's brand new, so it may take some modifications to work properly.

1. git clone https://github.com/KernelCafe/automation.git /tmp
2. cd /tmp/automation/cmd/prepare-node
3. sudo ./prep-node.sh

If it fails, you can run parts of the automation, such as prep-ansible.sh and prep-kconfsync.sh manually.

Manual

1. Create the barista user

On Linux, run:

sudo groupadd -g 2000 barista
sudo useradd -m -g barista -G -r barista

2. (Optional) Setup automatic system configuration backups

To track changes to your system configuration, we have a script that syncs changes to directories like /etc and /usr/local/etc to a GitHub repository. It is recommended that you configure this before introducing further changes.

sudo su - barista
cd $HOME
git clone https://github.com/KernelCafe/automation.git
cat /dev/zero | ssh-keygen -q -N ""
git config --global user.email "$(hostname -s)@kernel.cafe"
git config --global user.name "$(hostname -s)"

1. Add the contents of $HOME/.ssh/id_rsa.pub` to https://github.com/settings/keys
2. Create a GitHub repository: we typically do so as KernelCafe/host-$(hostname -s)

Then run, as the barista user:

cd $HOME
repo=host-$(hostname -s)
git clone git@github.com:KernelCafe/$repo.git
cd $repo
cp ../automation/cmd/kconfsync/kconfsync.sh sync.sh
cp ../automation/cmd/kconfsync/gitignore .gitignore
./sync.sh

If it works, then install the crontab, as the barista user:

tf=$(mktemp)
echo "*/5 * * * * $HOME/${repo}/sync.sh" > $tf
crontab $tf

3. Give the 'barista' user access to sudo

As an administrative user, run visudo and add a line that gives the barista user access to run commands as root:

barista ALL = (ALL) NOPASSWD: ALL

4. Enable 'ansible' to login as the 'barista' user

sudo su - barista
mkdir -p $HOME/.ssh
cp $HOME/automation/cmd/prepare-node/barista.pub $HOME/.ssh/authorized_keys
chmod 700 $HOME/.ssh
chmod 400 $HOME/.ssh/*

5. Add to node list

To get your node hooked into DNS and ansible, add a PR to update https://github.com/KernelCafe/welcome/blob/main/nodes/nodes.yaml

Steps we will take:

1. Update DNS records at https://www.name.com/account/domain/details/kernel.cafe#dns
2. https://github.com/KernelCafe/automation/blob/main/ansible/hosts
3. Run ansible-playbook -i hosts playbooks/users.yaml