Remote job execution¶
Ansible Runner supports the concept that a job run may be requested on one host but executed on another. This capability is primarily intended to be used by Receptor.
Support for this in Runner involves a three phase process.
Transmit: Convert the job to a binary format that can be sent to the worker node.
Worker: Actually execute the job.
Process: Receive job results and process them.
The following command illustrates how the three phases work together:
$ ansible-runner transmit ./demo -p test.yml | ansible-runner worker | ansible-runner process ./demo
In this example, the ansible-runner transmit command is given a private data directory of ./demo and told to select the test.yml playbook from it. Instead of executing the playbook as ansible-runner run would do, the data dir and command line parameters are converted to a compressed binary stream that is emitted as stdout. The transmit command generally takes the same command line parameters as the run command.
The ansible-runner worker command accepts this stream, runs the playbook, and generates a new compressed binary stream of the resulting job events and artifacts. This command optionally accepts the –private-data-dir option. If provided, it will extract the contents sent from ansible-runner transmit into that directory.
The ansible-runner process command accepts the result stream from the worker, and fires all the normal callbacks and does job event processing. In the command above, this results in printing the playbook output and saving artifacts to the data dir. The process command takes a data dir as a parameter, to know where to save artifacts.
Cleanup of Resources Used by Jobs¶
The transmit and process commands do not offer any automatic deletion of the private data directory or artifacts, because these are how the user interacts with runner.
When running ansible-runner worker, if no –private-data-dir is given,
it will extract the contents to a temporary directory which is deleted at the end of execution.
--private-data-dir option is given, then the directory will persist after the run finishes
--delete flag is also set. In that case, the private data directory will be deleted before execution if it exists and also removed after execution.
The following command offers out-of-band cleanup.
$ ansible-runner worker cleanup –file-pattern=/tmp/foo_*
This would assure that old directories that fit the file glob “/tmp/foo_*” are deleted, which would could be used to assure cleanup of paths created by commands like ansible-runner worker –private_data_dir=/tmp/foo_3, for example. NOTE: see the –grace-period option, which sets the time window.
This command also takes a –remove-images option to run the podman or docker rmi command. There is otherwise no automatic cleanup of images used by a run, even if container_auth_data is used to pull from a private container registry. To be sure that layers are deleted as well, the –image-prune flag is necessary.
Python code importing Ansible Runner can make use of these facilities by setting the streamer parameter to ansible_runner.interface.run. This parameter can be set to transmit, worker or process to invoke each of the three stages. Other parameters are as normal in the CLI.