ansible: Add missing default variables for common-node

[lttng-ci.git] / automation / ansible / README.md

# Setup on Ubuntu

```
apt install ansible ansible-mitogen
```

# Required collections

```
ansible-galaxy install -r roles/requirements.yml
```

# Privileged data

Privileged data is stored in Bitwarden. To use roles that fetch privileged data,
the following utilities must be available:

* [bw](https://bitwarden.com/help/cli/)

Once installed, login and unlock the vault:

```
bw login # or, `bw unlock`
export BW_SESSION=xxxx
bw sync -f
```

# Running playbooks

```
ansible-playbook -i hosts [-l SUBSET] site.yaml
```

# Bootstrapping hosts

## Windows

1. Configure either SSH or WinRM connection: see https://docs.ansible.com/ansible/latest/os_guide/windows_setup.html
2. For arm64 hosts:
  * Install the necessary optional features (eg. OpenSSH, Hyper-V) since Windows RSAT isn't available on Arm64 yet

## CI 'rootnode'

1. Add the new ansible node to the `node_standalone` group in the inventory
2. Add an entry to the `vms` variable in the host vars for the libvirt host
  * See the defaults and details in `roles/libvirt/vars/main.yml` and `roles/libvirt/tasks/main.yml`
  * Make sure to set the `cdrom` key to the path of ISO for the installer
3. Run the playbook, eg. `ansible-playbook -i hosts -l cloud07.internal.efficios.com site.yml`
  * The VM should be created and started
4. Once the VM is installed take a snapshot so that Jenkins may revert to the original state
  * `ansible-playbook playbooks/snapshot-rootnode.yml -e '{"revert_before": false}' -l new-rootnode`

### Ubuntu auto-installer

1. Note your IP address
2. Switch to the directory with the user-data files: `cd roles/libvirt/files`
3. Write out the instance-specific metadata, eg.

```
cat > meta-data <<EOF
instance-id: iid-XXX
hostname: XXX.internal.efficios.com
EOF
```
  * The instance-id is used to determine if re-installation is necessary.
4. Start a python web server: `python3 -m http.server 3003`
5. Connect to the VM using a remote viewer on the address given by `virsh --connect qemu+ssh://root@host/system domdisplay`
6. Edit the grub boot options for the installer and append the following as arguments for the kernel: `autoinstall 'ds=nocloud-net;s=http://IPADDRESS:3003/'` and boot the installer
  * Note that the trailing `/` and quoting are important
  * The will load the `user-data`, `meta-data`, and `vendor-data` files in the directory served by the python web server
7. After the installation is complete, the system will reboot and run cloud-init for the final portion of the initial setup. Once completed, ansible can be run against it using the ubuntu user and becoming root, eg. `ansible-playbook -i hosts -u ubuntu -b ...`

# LXD Cluster

## Start a new cluster

1. For the initial member of the cluster, set the `lxd_cluster` variable in the host variables to something similar to:

```
lxd_cluster:
  server_name: cluster-member-name
  enabled: true
  member_config:
    - entity: storage-pool
      name: default
      key: source
      value: tank/lxd
```

2. Run the `site.yml` playbook on the node
3. Verify that storage pool is configured:

```
$ lxc storage list
| name    | driver | state   |
| default | zfs    | created |
```

  * If not present, create it on necessary targets:

```
$ lxc storage create default zfs source=tank/lxd --target=cluster-member-name
# Repeat for any other members
# Then, on the member itself
$ lxc storage create default zfs
# The storage listed should not be in the 'pending' state
```

4. Create a metrics certificate pair for the cluster, or use an existing one

```
openssl req -x509 -newkey ec -pkeyopt ec_paramgen_curve:secp384r1 -sha384 -keyout metrics.key -nodes -out metrics.crt -days 3650 -subj "/CN=metrics.local"
lxc config trust add metrics.crt --type=metrics
```

## Adding a new host

1. Generate a token for the new member: `lxc cluster add member-host-name`
2. In the member's host_var's file set the following key:
  * `lxd_cluster_ip`: The IP address on which the server will listen
  * `lxd_cluster`: In a fashion similar to the following entry
```
lxd_cluster:
  enabled: true
  server_address: 172.18.0.192
  cluster_token: 'xxx'
  member_config:
    - entity: storage-pool
      name: default
      key: source
      value: tank/lxd
```
  * The `cluster_token` does not need to be kept in git after the the playbook's first run
3. Assuming the member is in the host's group of the inventory, run the `site.yml` playbook.

## Managing instances

Local requirements:

 * python3, python3-dnspython, samba-tool, kinit

To automatically provision instances, perform certain operations, and update DNS entries:

1. Update `vars/ci-instances.yml`
2. Open a kerberos ticket with `kinit`
3. Run the playbook, eg. `ansible-playbook playbooks/ci-instances.yml`