ansible-infra/docs/create-new-web-service-vm.md
Stefan Bethke 0c782caee7
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Explain what all needs to be added for a new host
2026-01-25 14:03:34 +01:00

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# How to create all necessary entries for new (web service) VM
Let's assume that you want to add a new web service `example.hamburg.ccc.de` which is going to be hosted on the VM `example` on chaosknoten. These are the steps that you need to take to create the VM and add it to the Ansible repo.
## IP, DNS, VM
1. Allocate a fresh [IPv6 in Netbox in the 2a00:14b0:42:102::/64 net](https://netbox.hamburg.ccc.de/ipam/prefixes/47/ip-addresses/). This will be the management address for the VM.
2. Add an entry `example.hosts.hamburg.ccc.de` with that AAAA to the name server (`ns-intern`).
3. Add an entry `example.hamburg.ccc.de` as a CNAME for `public-reverse-proxy` to the same zone.
4. Commit and reload the zone.
5. Create a new VM on chaosknoten, for example by cloning the Debian template 9023. Give it the name `example`.
6. Edit the ethernet interface to be connected to `vmbr0`, VLAN tag `2`.
7. Configure the IPv6 address in the Cloud-Init section. Leave IPv4 set to DHCP.
8. Make sure the VM is started at boot (options).
9. Adjust any other VM parameters as needed.
10. Boot the VM.
11. Add the [VM to Netbox](https://netbox.hamburg.ccc.de/virtualization/virtual-machines/). Make sure to enter the VM ID.
12. Add an Ethernet interface to the VM; we typically use `eth0` as a name.
13. Add IP for that interface, then choose "Assign IP" and search for the IP you've created. Make it the primary IP of that interface.
## Ansible Basics
As the first step, we need to make the host known to Ansible.
1. In `.sops.yaml`, add an entry for the host. Follow the other entries there.
1. `keys.hosts.chaosknoten.age` needs an age public key (the private key is needed in the host-specific YAML)
2. `creation_rules` needs an entry for the host, referencing the age key.
2. In `inventories/chaosknoten/hosts.yaml`:
1. Configure basic connection info:
```
example:
ansible_host: example.hosts.hamburg.ccc.de
ansible_user: chaos
ansible_ssh_common_args: -J ssh://chaos@router.hamburg.ccc.de
```
You typically will want to use router as a jump host so that you can run Ansible on an IPv4 only connection.
2. Add the host to the desired roles. As a minimum, you'll want `base_config_hosts` and `infrastructure_authorized_keys_hosts`. For a typical web service based on Docker Compose, you'll want `docker_compose_hosts`, `nginx_hosts`, and `certbot_hosts`.
3. In the directorry `inventories/chaosknoten/host_var/`:
1. A file `inventories/chaosknoten/host_var/example.yaml` with the host/service specific configuration.
2. A file `inventories/chaosknoten/host_var/example.sops.yaml` with the encrypted secrets for the host/service. Run `sops inventories/chaosknoten/host_var/example.yaml` to edit/create that file. Entries there should generally be prefixed with `secret__` to make it easier to see where that variable is coming from in templates etc.
## Service-specific config
From here, we go into the details of the web service that you want to configure. For a typical web service with Docker Compose, you will likely want to configure the following.
Make `inventories/chaosknoten/host_var/example.yaml` look like this:
```yaml
certbot__version_spec: ""
certbot__acme_account_email_address: le-admin@hamburg.ccc.de
certbot__certificate_domains:
- "example.hamburg.ccc.de"
certbot__new_cert_commands:
- "systemctl reload nginx.service"
docker_compose__compose_file_content: "{{ lookup('ansible.builtin.template', 'resources/chaosknoten/example/docker_compose/compose.yaml.j2') }}"
nginx__version_spec: ""
nginx__configurations:
- name: example.hamburg.ccc.de
content: "{{ lookup('ansible.builtin.file', 'resources/chaosknoten/spaceapiccc/nginx/example.hamburg.ccc.de.conf') }}"
```
This will create `compose.yaml` from the template `resources/chaosknoten/example/docker_compose/compose.yaml.j2'`, and the nginx config from `resources/chaosknoten/spaceapiccc/nginx/example.hamburg.ccc.de.conf`. Of course, depending on your service, you might need additional entries. See the other hosts and the roles for more info.
## First Ansible run
Before you can run Ansible successfully, you will want to make sure you can connect to the VM, and that the host key has been added to your known hosts:
* `ssh chaos@example.hosts.hamburg.ccc.de`
* `ssh -J chaos@router.hamburg.ccc.de chaos@example.hosts.hamburg.ccc.de`
Then run Ansible for `public-reverse-proxy` to add the necessary entries: `ansible-playbook playbooks/deploy.yaml --inventory inventories/chaosknoten/hosts.yaml --limit public-reverse-proxy`.
Finally run Ansible for the new host: `ansible-playbook playbooks/deploy.yaml --inventory inventories/chaosknoten/hosts.yaml --limit example`
# Commit your changes
Do not forget to commit your changes, whether it's a new host or you are making changes to an existing host.
And always `git pull` before you run Ansible so avoid reverting anything!