bare(-metal servers) v23

Suggest edits

Set platform: bare in config.yml

This platform is meant to support any server that is accessible via SSH, including bare-metal servers as well as already-provisioned servers on any cloud platform (including AWS).

You must define the IP address(es) and username for each target server:

instances:
  - node: 1
    Name: igor
    platform: bare
    public_ip: 192.0.2.1
    private_ip: 192.0.2.222
    vars:
      ansible_user: xyzzy

You must ensure that

  1. TPA can ssh to the instance as ansible_user
  2. The ansible_user has sudo access on the instance

SSH access

In the example above, TPA will ssh to xyzzy@192.0.2.1 to access the instance.

By default, TPA will run ssh-keygen to generate a new SSH keypair in your cluster directory. The private key is named id_cluster_name and the public key is stored in id_cluster_name.pub.

You must either set ssh_key_file: /path/to/id_keyname to use a different key that the instance will accept, or configure the instance to allow access from the generated key (e.g., use ssh-copy-id, which will append the contents of id_cluster_name.pub to ~xyzzy/.ssh/authorized_keys).

You must also ensure that ssh can verify the host key(s) of the instance. You can either add entries to the known_hosts file in your cluster directory, or install the TPA-generated host keys from hostkeys/ssh_host_*_key* in your cluster directory into /etc/ssh on the instance (the generated tpa_known_hosts file contains entries for these keys).

For example, to ssh in with the generated user key, but keep the existing host keys, you can do:

$ cd ~/clusters/speedy
$ ssh-copy-id -i id_speedy xyzzy@192.0.2.1
$ ssh-keyscan -H 192.0.2.1 >> tpa_known_hosts

Run tpaexec ping ~/clusters/speedy to check if it's working. If not, append -vvv to the command to look at the complete ssh command-line. (Note: Ansible will invoke ssh to execute a command like bash -c 'python3 && sleep 0' on the instance. If you run ssh commands by hand while debugging, replace this with a command that produces some output and then exits instead, e.g., 'id'.)

For more details:

Distribution support

TPA will try to detect the distribution running on target instances, and fail if it is not supported. TPA currently supports Debian (8/9/10; or jessie/stretch/buster), Ubuntu (16.04/18.04/20.04; or xenial/bionic/focal), and RHEL/CentOS/Rocky/AlmaLinux (7.x/8.x) on bare instances.

IP addresses

You can specify the public_ip, private_ip, or both for any instance.

TPA uses these IP addresses in two ways: first, to ssh to the instance to execute commands during deployment; and second, to set up communications within the cluster, e.g., for /etc/hosts or to set primary_conninfo for Postgres.

If you specify a public_ip, it will be used to ssh to the instances during deployment. If you specify a private_ip, it will be used to set up communications within the cluster. If you specify both, the public_ip will be used during deployment, and the private_ip for cluster communications.

If you specify only one or the other, the address will be used for both purposes. For example, you could set only public_ip for servers on different networks, or only private_ip if you're running TPA inside a closed network. (Instead of using public/private, you can set ip_address if you need to specify only one IP address.)