There is no guarantee on the ordering select() returns file descriptors.
So if, e.g. in the case of sudo_nonexistent.yml, sudo prints an error
to a single FD before exitting, there was previously no gurantee
iter_read() would read off the error before failing due to detecting
disconnect on any FD.
Now instead we keep reading while any non-disconnected FD exists.
Presently there is still no mechanism to add :attr:`tty_stream` to the
multiplexer after connection is successful, but for now it's not
expected that anything will be logged to it anyway.
Closes#148.
Now Connection.close() *must* be called in the worker, to ensure the
reference count for a context drops correctly.
Remove 'discriminator' for now, I'm not using it for testing any more
and it complicated this code.
This code is a car crash, it needs rewritten again. Ideally some/most of
this behaviour could live on services.DeduplicatingService somehow, but
I couldn't come up with a sensible design.
Lots of "invalid handle: ..., 102" messages started appearing during
exit recently because ordering changed slightly, and local handles were
sent _DEAD even though the broker loop was still progressing through
shutdown.
The "shutdown" event is too early to close handles: it is the start of
the grace period where streams and downstream contexts can finish up any
work and deliver buffered data, including FORWARD_LOG messages that
haven't arrived yet.
So instead,
- move the _DEAD logic to the "exit" event,
- get rid of Context.on_shutdown() entirely, it's been unused for over
a month,
- get rid of the "crash" event, since it always fires prior to "exit",
and its only use was to send _DEAD to local handles, which now happens
during exit anyway.
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.
These are generated by any child calling .context_by_id() without
previously knowing the context's name, such as Contexts set in
ExternalContext.master and ExternalContext.parent.
When a stream (such as unix.connect()) has its auth_id set to the
current context's, we should allow those requests too, since the request
is working with the privilege of the current context.
Benefits:
- More correct than re.sub()
- Better handling of trailing whitespace
- Recognises doc-strings regardless of quoting style
Limitations:
- Still not entirely correct
- Creates a syntax error when function/class body is only a docstring
- Doesn't handle indented docstrings yet
- Slower by 50x - 8-10 ms vs 0.2 ms for re.sub()
- Not much scope for improving this, tokenize is 100% pure Python
- Complex state machine, harder to understand
- Higher line count in parent.py
- Untested with Mitogen parent on Python 2.x and child on Python 2.x+y
No change
- Only requires Python stdlib modules
David Wilson