Closes#105.
References #155.
mitogen/service.py:
Refactor services to support individually exposed methods with
different security policies for each method.
- @mitogen.service.expose() to expose a method and set its policy
- @mitogen.service.arg_spec() to validate input.
- Require basic service message format to be a tuple of
`(method, kwargs)`, where kwargs is always a dict.
- Update DeduplicatingService to match the new scheme.
ansible_mitogen/connection.py:
- Rename 'method' to 'method_name' to disambiguate it from the
service.call()'s method= argument.
ansible_mitogen/planner.py:
- Generate an ID for every job, sync or not, and fetch job results
from JobResultService rather than via the initiating function
call's return value.
- Planner subclasses now get to select whether their Runner should
run in a forked process. The base implementation requests this if
the 'mitogen_isolation_mode=fork' task variable is present.
ansible_mitogen/runner.py:
Teach runners to deliver their result via JobResultService executing
in their indirect parent mux process.
ansible_mitogen/plugins/actions/mitogen_async_status.py:
Split the implementation up into methods, and more compatibly
emulate Ansible's existing output.
ansible_mitogen/process.py:
Mux processes now host JobResultService.
ansible_mitogen/services.py:
Update existing services to the new mitogen.service scheme, and
implement JobResultService:
* listen() method for synchronous jobs. planner.invoke() registers a
Sender with the service prior to invoking the job, then sleeps
waiting for the service to write the job result to the
corresponding Receiver.
* Non-blocking get() method for implementing mitogen_async_status
action.
* Child-accessible push() method for delivering task results.
ansible_mitogen/target.py:
New helpers for spawning a virginal subprocess on startup, from
which asynchronous and mitogen_task_isolation=fork jobs are forked.
Necessary to avoid a task inheriting potentially
polluted/monkey-patched parent environment, since remaining jobs
continue to run in the original child process.
docs/ansible.rst:
Add/merge/remove some behaviours/risks.
tests/ansible/integration:
New tests for forking/async.
Before:
$ ANSIBLE_STRATEGY=mitogen ansible -i derp, derp -m setup
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: (''.join(bits)[-300:],)
derp | FAILED! => {
"msg": "Unexpected failure during module execution.",
"stdout": ""
}
After:
$ ANSIBLE_STRATEGY=mitogen ansible -i derp, derp -m setup
derp | UNREACHABLE! => {
"changed": false,
"msg": "EOF on stream; last 300 bytes received: 'ssh: Could not resolve hostname derp: nodename nor servname provided, or not known\\r\\n'",
"unreachable": true
}
* Use identical logic to select when stdout/stderr are merged, so
'stdout', 'stdout_lines', 'stderr', 'stderr_lines' contain the same
output before/after the extension.
* When stdout/stderr are merged, synthesize carriage returns just like
the TTY layer.
* Mimic the SSH connection multiplexing message on stderr. Not really
for user code, but so compare_output_test.sh needs fewer fixups.
Rather than assume any structure about the Python code:
* Delete the exit_json/fail_json monkeypatches.
* Patch SystemExit rather than a magic monkeypatch-thrown exception
* Setup fake cStringIO stdin, stdout, stderr and return those along with
SystemExit exit status
* Setup _ANSIBLE_ARGS as we used to, since we still want to override
that with '{}' to prevent accidental import hangs, but also provide
the same string via sys.stdin.
* Compile the module bytecode once and re-execute it for every
invocation. May change this back again later, once some benchmarks are
done.
* Remove the fixups stuff for now, it's handled by ^ above.
Should support any "somewhat new style" Python module, including those
that just give up and dump stuff to stdout directly.
Refactor planner.py to look a lot more like runner.py. This 'structural
cutpaste' looks messy -- probably we can simplify this code, even though
it's pretty simple already.
* Add helpers.get_file() that calls back up into FileService as
necessary. This is a stopgap measure.
* Add logging to exec_args() to simplify debugging of binary runners.
It looks a lot like multiple calls to _make_tmp_path() will result in
multiple temporary directories on the remote machine, only the last of
which will be cleaned up.
We must be bug-for-bug compatible for now, so ignore the problem in the
meantime.
David Wilson