Running Tenks

Commands

Tenks has a variable cmd which specifies the command to be run. This variable can be set in your override file (see Configuration). The possible values it can take are:

• deploy: create a virtual cluster to the specification given. This is the default command.

• teardown: tear down any existing virtual cluster with the specification given.

Execution

Currently, Tenks does not have a CLI or wrapper. Before running any of the ansible-playbook commands in this section, ensure that your Tenks virtualenv is active (see Installation). In this section, override.yml represents the path to your override file (see Configuration).

The deploy.yml playbook will run deployment from start to finish. This can be run by calling:

(tenks) $ ansible-playbook --inventory ansible/inventory ansible/deploy.yml --extra-vars=@override.yml

teardown.yml is deploy.yml’s “mirror image” to tear down a cluster. This can be run by calling:

(tenks) $ ansible-playbook --inventory ansible/inventory ansible/teardown.yml --extra-vars=@override.yml

deploy.yml and teardown.yml automatically set cmd appropriately, and they contain various constituent playbooks which perform different parts of the deployment. An individual section of Tenks can be run separately by substituting the path to the playbook(s) you want to run into one of the commands above. The current playbooks can be seen in the Ansible structure diagram in Architecture. Bear in mind that you will have to set cmd in your override file if you are running any of the sub-playbooks individually.

Once a cluster has been deployed, it can be reconfigured by modifying the Tenks configuration and rerunning deploy.yml. Node specs can be changed (including increasing/decreasing the number of nodes); node types can also be reconfigured. Existing nodes will be preserved where possible.