Commit Graph

201 Commits

Author SHA1 Message Date
John Snow
0f71c9a936 python/aqmp: Remove scary message
The scary message interferes with the iotests output. Coincidentally, if
iotests works by removing this, then it's good evidence that we don't
really need to scare people away from using it.

Signed-off-by: John Snow <jsnow@redhat.com>
Acked-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-id: 20211026175612.4127598-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-11-01 11:54:59 -04:00
John Snow
49a608b8c2 python/machine: Handle QMP errors on close more meticulously
To use the AQMP backend, Machine just needs to be a little more diligent
about what happens when closing a QMP connection. The operation is no
longer a freebie in the async world; it may return errors encountered in
the async bottom half on incoming message receipt, etc.

(AQMP's disconnect, ultimately, serves as the quiescence point where all
async contexts are gathered together, and any final errors reported at
that point.)

Because async QMP continues to check for messages asynchronously, it's
almost certainly likely that the loop will have exited due to EOF after
issuing the last 'quit' command. That error will ultimately be bubbled
up when attempting to close the QMP connection. The manager class here
then is free to discard it -- if it was expected.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20211026175612.4127598-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-11-01 11:54:59 -04:00
John Snow
b9420e4f4b python/machine: remove has_quit argument
If we spy on the QMP commands instead, we don't need callers to remember
to pass it. Seems like a fair trade-off.

The one slightly weird bit is overloading this instance variable for
wait(), where we use it to mean "don't issue the qmp 'quit'
command". This means that wait() will "fail" if the QEMU process does
not terminate of its own accord.

In most cases, we probably did already actually issue quit -- some
iotests do this -- but in some others, we may be waiting for QEMU to
terminate for some other reason, such as a test wherein we tell the
guest (directly) to shut down.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20211026175612.4127598-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-11-01 11:54:59 -04:00
John Snow
461044ceb4 python: Add iotest linters to test suite
Run mypy and pylint on the iotests files directly from the Python CI
test infrastructure. This ensures that any accidental breakages to the
qemu.[qmp|aqmp|machine|utils] packages will be caught by that test
suite.

It also ensures that these linters are run with well-known versions and
test against a wide variety of python versions, which helps to find
accidental cross-version python compatibility issues.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-id: 20211019144918.3159078-15-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-11-01 11:54:59 -04:00
John Snow
c163c723ef python, iotests: remove socket_scm_helper
It's not used anymore, now.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210923004938.3999963-11-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:11 -04:00
John Snow
514d00df5f python/qmp: add send_fd_scm directly to QEMUMonitorProtocol
It turns out you can do this directly from Python ... and because of
this, you don't need to worry about setting the inheritability of the
fds or spawning another process.

Doing this is helpful because it allows QEMUMonitorProtocol to keep its
file descriptor and socket object as private implementation
details. /that/ is helpful in turn because it allows me to write a
compatible, alternative implementation.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210923004938.3999963-10-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:11 -04:00
John Snow
d911accf0a python/qmp: clear events on get_events() call
All callers in the tree *already* clear the events after a call to
get_events(). Do it automatically instead and update callsites to remove
the manual clear call.

These semantics are quite a bit easier to emulate with async QMP, and
nobody appears to be abusing some emergent properties of what happens if
you decide not to clear them, so let's dial down to the dumber, simpler
thing.

Specifically: callers of clear() right after a call to get_events() are
more likely expressing their desire to not see any events they just
retrieved, whereas callers of clear_events() not in relation to a recent
call to pull_event/get_events are likely expressing their desire to
simply drop *all* pending events straight onto the floor. In the sync
world, this is safe enough; in the async world it's nearly impossible to
promise that nothing happens between getting and clearing the
events.

Making the retrieval also clear the queue is vastly simpler.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210923004938.3999963-9-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:11 -04:00
John Snow
3a3d84f5ec python/aqmp: Disable logging messages by default
AQMP is a library, and ideally it should not print error diagnostics
unless a user opts into seeing them. By default, Python will print all
WARNING, ERROR or CRITICAL messages to screen if no logging
configuration has been created by a client application.

In AQMP's case, ERROR logging statements are used to report additional
detail about runtime failures that will also eventually be reported to the
client library via an Exception, so these messages should not be
rendered by default.

(Why bother to have them at all, then? In async contexts, there may be
multiple Exceptions and we are only able to report one of them back to
the client application. It is not reasonably easy to predict ahead of
time if one or more of these Exceptions will be squelched. Therefore,
it's useful to log intermediate failures to help make sense of the
ultimate, resulting failure.)

Add a NullHandler that will suppress these messages until a client
application opts into logging via logging.basicConfig or similar. Note
that upon calling basicConfig(), this handler will *not* suppress these
messages from being displayed by the client's configuration.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210923004938.3999963-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:11 -04:00
John Snow
3e55dc35b8 python/aqmp: Reduce severity of EOFError-caused loop terminations
When we encounter an EOFError, we don't know if it's an "error" in the
perspective of the user of the library yet. Therefore, we should not log
it as an error. Reduce the severity of this logging message to "INFO" to
indicate that it's something that we expect to occur during the normal
operation of the library.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210923004938.3999963-7-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:11 -04:00
John Snow
58026b11f3 python/aqmp: Add dict conversion method to Greeting object
The iotests interface expects to return the greeting as a dict; AQMP
offers it as a rich object.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210923004938.3999963-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:10 -04:00
John Snow
6e2f6ec561 python/aqmp: add send_fd_scm
Add an implementation for send_fd_scm to the async QMP implementation.
Like socket_scm_helper mentions, a non-empty payload is required for
QEMU to process the ancillary data. A space is most useful because it
does not disturb the parsing of subsequent JSON objects.

A note on "voiding the warranty":

Python 3.11 removes support for calling sendmsg directly from a
transport's socket. There is no other interface for doing this, our use
case is, I suspect, "quite unique".

As far as I can tell, this is safe to do -- send_fd_scm is a synchronous
function and we can be guaranteed that the async coroutines will *not* be
running when it is invoked. In testing, it works correctly.

I investigated quite thoroughly the possibility of creating my own
asyncio Transport (The class that ultimately manages the raw socket
object) so that I could manage the socket myself, but this is so wildly
invasive and unportable I scrapped the idea. It would involve a lot of
copy-pasting of various python utilities and classes just to re-create
the same infrastructure, and for extremely little benefit. Nah.

Just boldly void the warranty instead, while I try to follow up on
https://bugs.python.org/issue43232

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210923004938.3999963-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:10 -04:00
John Snow
6bfebc7306 python/aqmp: Return cleared events from EventListener.clear()
This serves two purposes:

(1) It is now possible to discern whether or not clear() removed any
event(s) from the queue with absolute certainty, and

(2) It is now very easy to get a List of all pending events in one
chunk, which is useful for the sync bridge.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210923004938.3999963-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:10 -04:00
John Snow
16cce725ed python/aqmp: add .empty() method to EventListener
Synchronous clients may want to know if they're about to block waiting
for an event or not. A method such as this is necessary to implement a
compatible interface for the old QEMUMonitorProtocol using the new async
internals.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210923004938.3999963-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:10 -04:00
John Snow
0257209a09 python/aqmp: add greeting property to QMPClient
Expose the greeting as a read-only property of QMPClient so it can be
retrieved at-will.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210923004938.3999963-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:10 -04:00
G S Niteesh Babu
99e45a6131 python/aqmp-tui: Add syntax highlighting
Add syntax highlighting for the incoming and outgoing QMP messages.
This is achieved using the pygments module which was added in a
previous commit.

The current implementation is a really simple one which doesn't
allow for any configuration. In future this has to be improved
to allow for easier theme config using an external config of
some sort.

Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Message-Id: <20210823220746.28295-6-niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
G S Niteesh Babu
f37c34d601 python: add optional pygments dependency
Added pygments as optional dependency for AQMP TUI.
This is required for the upcoming syntax highlighting feature
in AQMP TUI.
The dependency has also been added in the devel optional group.

Added mypy 'ignore_missing_imports' for pygments since it does
not have any type stubs.

Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Message-Id: <20210823220746.28295-5-niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
G S Niteesh Babu
35755f7d4f python: Add entry point for aqmp-tui
Add an entry point for aqmp-tui. This will allow it to be run from
the command line using "aqmp-tui localhost:1234"
More options available in the TUI can be found using "aqmp-tui -h"

Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Message-Id: <20210823220746.28295-4-niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
G S Niteesh Babu
aeb6b48a47 python/aqmp-tui: Add AQMP TUI
Added AQMP TUI.

Implements the follwing basic features:
1) Command transmission/reception.
2) Shows events asynchronously.
3) Shows server status in the bottom status bar.
4) Automatic retries on disconnects and error conditions.

Also added type annotations and necessary pylint/mypy configurations.

Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Message-Id: <20210823220746.28295-3-niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
G S Niteesh Babu
974e2f4722 python: Add dependencies for AQMP TUI
Added dependencies for the upcoming AQMP TUI under the optional
'tui' group.

The same dependencies have also been added under the devel group
since no work around has been found for optional groups to imply
other optional groups.

Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Message-Id: <20210823220746.28295-2-niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
a4ffaecd57 python/aqmp: Add Coverage.py support
I'm not exposing this via the Makefile help, it's not likely to be
useful to passersby. Switch the avocado runner to the 'legacy' runner
for now, as the new runner seems to obscure coverage reports, again.

Usage is to enter your venv of choice and then:
`make check-coverage && xdg-open htmlcov/index.html`.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-28-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
8193b9d148 python/aqmp: add LineProtocol tests
Tests a real connect, a real accept, and really sending and receiving a
message over a UNIX socket.

Brings coverage of protocol.py up to ~93%.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-27-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
a1f71b61ea python/aqmp: add AsyncProtocol unit tests
This tests most of protocol.py -- From a hacked up Coverage.py run, it's
at about 86%. There's a few error cases that aren't very well tested
yet, they're hard to induce artificially so far. I'm working on it.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-26-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
4320f7172f python: bump avocado to v90.0
Avocado v90 includes improved support for running async unit tests. The
workaround that existed prior to v90 causes the unit tests to fail
afterwards, however, so upgrade our minimum version pin to the very
latest and greatest.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-25-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
ed6d4d7a95 python/aqmp: add scary message
Add a warning whenever AQMP is used to steer people gently away from
using it for the time-being.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-24-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
debbabd77f python/aqmp: add asyncio_run compatibility wrapper
As a convenience. It isn't used by the library itself, but it is used by
the test suite. It will also come in handy for users of the library
still on Python 3.6.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-23-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
41f4f92260 python/aqmp: add _raw() execution interface
This is added in anticipation of wanting it for a synchronous wrapper
for the iotest interface. Normally, execute() and execute_msg() both
raise QMP errors in the form of Python exceptions.

Many iotests expect the entire reply as-is. To reduce churn there, add a
private execution interface that will ease transition churn. However, I
do not wish to encourage its use, so it will remain a private interface.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-22-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
e0fea0b3ac python/aqmp: add execute() interfaces
Add execute() and execute_msg().

_execute() is split into _issue() and _reply() halves so that
hypothetical subclasses of QMP that want to support different execution
paradigms can do so.

I anticipate a synchronous interface may have need of separating the
send/reply phases. However, I do not wish to expose that interface here
and want to actively discourage it, so they remain private interfaces.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-21-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
577737be55 python/aqmp: Add message routing to QMP protocol
Add the ability to handle and route messages in qmp_protocol.py. The
interface for actually sending anything still isn't added until next
commit.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-20-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
4cd17f375d python/pylint: disable no-member check
mypy handles this better -- but we only need the workaround because
pylint under Python 3.6 does not understand that a MutableMapping really
does have a .get() method attached.

We could remove this again once 3.7 is our minimum.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-19-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
c67d696b85 python/aqmp: add QMP protocol support
The star of our show!

Add most of the QMP protocol, sans support for actually executing
commands. No problem, that happens in the next several commits.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-18-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
29a8ea9ba2 python/pylint: disable too-many-function-args
too-many-function-args seems prone to failure when considering
things like Method Resolution Order, which mypy gets correct. When
dealing with multiple inheritance, pylint doesn't seem to understand
which method will actually get called, while mypy does.

Remove the less powerful, redundant check.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-17-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
b3cda213a7 python/aqmp: add QMP event support
This class was designed as a "mix-in" primarily so that the feature
could be given its own treatment in its own python module.

It gets quite a bit too long otherwise.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-16-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
ad07299941 python/aqmp: add well-known QMP object models
The QMP spec doesn't define very many objects that are iron-clad in
their format, but there are a few. This module makes it trivial to
validate them without relying on an external third-party library.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-15-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
08f98a2231 python/aqmp: add QMP Message format
The Message class is here primarily to serve as a solid type to use for
mypy static typing for unambiguous annotation and documentation.

We can also stuff JSON serialization and deserialization into this class
itself so it can be re-used even outside this infrastructure.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-14-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
762bd4d7a7 python/aqmp: add AsyncProtocol._readline() method
This is added as a courtesy: many protocols are line-based, including
QMP. Putting it in AsyncProtocol lets us keep the QMP class
implementation just a pinch more abstract.

(And, if we decide to add a QTEST implementation later, it will need
this, too. (Yes, I have a QTEST implementation.))

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-13-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
12c7a57f5b python/aqmp: add _cb_inbound and _cb_outbound logging hooks
Add hooks designed to log/filter incoming/outgoing messages. The primary
intent for these is to be able to support iotests which may want to log
messages with specific filters for reproducible output.

Another use is for plugging into Urwid frameworks; all messages in/out
can be automatically added to a rendering list for the purposes of a
qmp-shell like tool.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-12-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
2686ac1316 python/aqmp: add configurable read buffer limit
QMP can transmit some pretty big messages, and the default limit of 64KB
isn't sufficient. Make sure that we can configure it.

Reported-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-11-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
774c64a58d python/aqmp: add AsyncProtocol.accept() method
It's a little messier than connect, because it wasn't designed to accept
*precisely one* connection. Such is life.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-10-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
50e533061f python/aqmp: add logging to AsyncProtocol
Give the connection and the reader/writer tasks nicknames, and add
logging statements throughout.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-9-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
c1408345af python/aqmp: Add logging utility helpers
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
c58b42e095 python/aqmp: add runstate state machine to AsyncProtocol
This serves a few purposes:

1. Protect interfaces when it's not safe to call them (via @require)

2. Add an interface by which an async client can determine if the state
has changed, for the purposes of connection management.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-7-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
4ccaab0377 python/aqmp: add generic async message-based protocol support
This is the bare minimum that you need to establish a full-duplex async
message-based protocol with Python's asyncio.

The features to be added in forthcoming commits are:

- Runstate tracking
- Logging
- Support for incoming connections via accept()
- _cb_outbound, _cb_inbound message hooks
- _readline() method

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
a07616d612 python/aqmp: add asyncio compatibility wrappers
Python 3.6 does not have all of the goodies that Python 3.7 does, and we
need to support both. Add some compatibility wrappers needed for this
purpose.

(Note: Python 3.6 is EOL December 2021.)

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
35b9a85ade python/pylint: Add exception for TypeVar names ('T')
'T' is a common TypeVar name, allow its use.

See also https://github.com/PyCQA/pylint/issues/3401 -- In the future,
we might be able to have a separate list of acceptable names for
TypeVars exclusively.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
fbfb6a37a3 python/aqmp: add error classes
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow
a093a65567 python/aqmp: add asynchronous QMP (AQMP) subpackage
For now, it's empty! Soon, it won't be.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:27 -04:00
John Snow
eb8033f658 python: pylint 2.11 support
We're not ready to enforce f-strings everywhere, so just silence this
new warning.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Message-id: 20210916182248.721529-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-16 15:04:04 -04:00
John Snow
5690b4370b python: Update for pylint 2.10
A few new annoyances. Of note is the new warning for an unspecified
encoding when opening a text file, which actually does indicate a
potentially real problem; see
https://www.python.org/dev/peps/pep-0597/#motivation

Use LC_CTYPE to determine an encoding to use for interpreting QEMU's
terminal output. Note that Python states: "language code and encoding
may be None if their values cannot be determined" -- use a platform
default as a backup.

Notes: Passing encoding=None will generate a suppressed warning on
Python 3.10+ that 'None' should not be passed as the encoding
argument. This behavior may be deprecated in the future and the default
switched to be a ubiquitous UTF-8. Opting in to the locale default will
be done by passing the encoding 'locale', but that isn't available in
3.6 through 3.9. Presumably this warning will be unsuppressed some time
prior to the actual switch and we can re-investigate these issues at
that time if necessary.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Message-id: 20210916182248.721529-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-16 15:03:56 -04:00
Vladimir Sementsov-Ogievskiy
15c3b863ee python:QEMUMachine: template typing for self returning methods
mypy thinks that return value of these methods in subclusses is
QEMUMachine, which is wrong. So, make typing smarter.

Suggested-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210824083856.17408-26-vsementsov@virtuozzo.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01 14:03:47 +02:00
Vladimir Sementsov-Ogievskiy
3f3c9b4c9d python/qemu/machine: QEMUMachine: improve qmp() method
We often call qmp() with unpacking dict, like qmp('foo', **{...}).
mypy don't really like it, it thinks that passed unpacked dict is a
positional argument and complains that it type should be bool (because
second argument of qmp() is conv_keys: bool).

Allow passing dict directly, simplifying interface, and giving a way to
satisfy mypy.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <20210824083856.17408-25-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01 14:03:47 +02:00