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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
