tpaexec provision#

Provision creates instances and other resources required by the cluster.

The exact details of this process depend both on the architecture (e.g. M1 ) and platform (e.g. Using awscli to change volume attributes ) that you selected while configuring the cluster.

At the end of the provisioning stage, you will have the required number of instances with the basic operating system installed, which TPA can access via ssh (with sudo to root).

Prerequisites#

Before you can provision a cluster, you must generate the cluster configuration with Cluster configuration

(and edit config.yml to fine-tune the configuration if needed).

You may need additional platform-dependent steps. For example, you need to obtain an AWS API access keypair to provision EC2 instances, or set up LXD or Docker to provision containers. Consult the platform documentation for details.

Quickstart#

tpaexec provision ~/clusters/speedy

PLAY [Provision cluster] **********************************************************
...

TASK [Set up EC2 instances] *******************************************************
changed: [localhost] => (item=us-east-1:uproar)
changed: [localhost] => (item=us-east-1:unravel)
changed: [localhost] => (item=us-east-1:kinsman)
...

TASK [Generate ssh_config file for the cluster] ***********************************
changed: [localhost]

PLAY RECAP ************************************************************************
localhost                  : ok=163  changed=35   unreachable=0    failed=0    skipped=44   rescued=0    ignored=2

real    4m42.726s
user    0m39.101s
sys     0m15.687s

This command will produce lots of output (append -v , -vv , etc. to the command if you want even more verbose output). The output is also logged to ansible.log in the cluster directory. This can be overriden by setting the environment variable ANSIBLE_LOG_PATH to the path and name of the desired logfile.

If it completes without error, you may proceed to run tpaexec deploy to install and configure software.

Options#

When provisioning cloud instances, it is especially important to make sure instances are directly traceable to a human responsible for them. By default, TPA will tag EC2 instances as being owned by the login name of the user running tpaexec provision .

Specify --owner <name> to change the name (e.g., if your username happens to be something generic, like postgres or ec2-user). You may use initials, or “Firstname Lastname”, or anything else to uniquely identify a person.

Any other options you specify are passed on to Ansible.

Accessing the instances#

After provisioning completes, you should be able to SSH to the instances (after a brief delay to allow the instances to boot up and install their SSH host keys). As shown in the output above, tpaexec will generate an ssh_config file for you to use.

cd ~/clusters/speedy
cat ssh_config

Host *
    Port 22
    IdentitiesOnly yes
    IdentityFile "id_speedy"
    UserKnownHostsFile known_hosts tpa_known_hosts
    ServerAliveInterval 60

Host uproar
    User admin
    HostName 3.88.255.205
Host unravel
    User admin
    HostName 54.80.99.142
Host kinsman
    User admin
    HostName 54.165.229.179

To login to a host, use the command ssh -F ssh_config followed by the hostname. For example ssh -F ssh_config uproar .

You can run tpaexec deploy immediately after provisioning. It will wait as long as required for the instances to come up. You do not need to wait for the instances to come up, or ssh in to them before you start deployment.

Generated files#

During the provisioning process, a number of new files will be created in the cluster directory:

ls ~/clusters/speedy

total 240
- rw-r--r-- 1 ams ams 193098 Aug  4 17:59 ansible.log
drwxr-xr-x 2 ams ams   4096 Aug  4 17:38 commands
- rw-r--r-- 1 ams ams   1442 Aug  4 17:54 config.yml
lrwxrwxrwx 1 ams ams     51 Aug  4 17:38 deploy.yml ->
                             /opt/EDB/TPA/architectures/M1/deploy.yml
drwxr-xr-x 2 ams ams   4096 Aug  4 17:38 hostkeys
- rw------- 1 ams ams   1675 Aug  4 17:38 id_speedy
- rw------- 1 ams ams   1438 Aug  4 17:38 id_speedy.ppk
- rw-r--r-- 1 ams ams    393 Aug  4 17:38 id_speedy.pub
drwxr-xr-x 4 ams ams   4096 Aug  4 17:50 inventory
- rw-r--r-- 1 ams ams   2928 Aug  4 17:50 tpa_known_hosts
- rw-r--r-- 1 ams ams    410 Aug  4 17:50 ssh_config
- rw-r--r-- 1 ams ams   3395 Aug  4 17:59 vars.json
drwxr-xr-x 2 ams ams   4096 Aug  4 17:38 vault

We’ve already studied the sshconfig file, which refers to the `id*files (an SSH keypair generated for the cluster) andtpa_known_hosts(the signatures of thehostkeys/` installed on the instances).

The vars.json file may be used by tpaexec provision on subsequent invocations with --cached .

The inventory/ directory contains static and dynamic inventory files as well as group and host variable definitions from config.yml.

cat inventory/00-speedy

[tag_Cluster_speedy]
uproar ansible_host=3.88.255.205 node=1 platform=aws
unravel ansible_host=54.80.99.142 node=2 platform=aws
kinsman ansible_host=54.165.229.179 node=3 platform=aws

cat inventory/group_vars/tag_Cluster_speedy/01-speedy.yml

cluster_name: speedy
cluster_tag: tag_Cluster_speedy
edb_repositories: []
failover_manager: repmgr
keyring_backend: system
postgres_flavour: postgresql
postgres_version: 14
preferred_python_version: python3
ssh_key_file: id_speedy
tpa_version: v23.33-24-g4c0909d1

cat inventory/host_vars/kinsman/01-instance_vars.yml

ansible_user: admin
location: main
region: us-east-1
role:

- barman

- log-server

- witness
upstream: uproar
volumes:

- device: /dev/xvda

- device: /dev/sdf
  volume_for: barman_data

If you now change a variable in config.yml and rerun provision, these files will be updated. If you don’t change the configuration, it won’t do anything. If you add a new instance in config.yml and rerun, it will bring up the new instance without affecting the existing ones.

tpaexec provision

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