On Wed, Feb 23, 2022 at 11:18:26AM -0500, John Snow wrote: > On Wed, Feb 23, 2022 at 10:44 AM Daniel P. Berrangé <berra...@redhat.com> > wrote: > > > > On Wed, Feb 23, 2022 at 10:41:11AM -0500, John Snow wrote: > > > On Wed, Feb 23, 2022 at 10:27 AM Daniel P. Berrangé <berra...@redhat.com> > > > wrote: > > > > > > > > On Wed, Feb 23, 2022 at 10:22:11AM -0500, John Snow wrote: > > > > > On Mon, Feb 21, 2022 at 10:55 AM Damien Hedde > > > > > <damien.he...@greensocs.com> wrote: > > > > > > > > > > > > This option makes qmp_shell exit (with error code 1) > > > > > > as soon as one of the following error occurs: > > > > > > + command parsing error > > > > > > + disconnection > > > > > > + command failure (response is an error) > > > > > > > > > > > > _execute_cmd() method now returns None or the response > > > > > > so that read_exec_command() can do the last check. > > > > > > > > > > > > This is meant to be used in combination with an input file > > > > > > redirection. It allows to store a list of commands > > > > > > into a file and try to run them by qmp_shell and easily > > > > > > see if it failed or not. > > > > > > > > > > > > Signed-off-by: Damien Hedde <damien.he...@greensocs.com> > > > > > > > > > > Based on this patch, it looks like you really want something > > > > > scriptable, so I think the qemu-send idea that Dan has suggested might > > > > > be the best way to go. Are you still hoping to use the interactive > > > > > "short" QMP command format? That might be a bad idea, given how flaky > > > > > the parsing is -- and how we don't actually have a published standard > > > > > for that format. We've *never* liked the bad parsing here, so I have a > > > > > reluctance to use it in more places. > > > > > > > > > > I'm having the naive idea that a script file could be as simple as a > > > > > list of QMP commands to send: > > > > > > > > > > [ > > > > > {"execute": "block-dirty-bitmap-add", "arguments": { ... }}, > > > > > ... > > > > > ] > > > > > > > > I'd really recommend against creating a new format for the script > > > > file, especially one needing opening & closing [] like this, as > > > > that isn't so amenable to dynamic usage/creation. ie you can't > > > > just append an extcra command to an existing file. > > > > > > > > IMHO, the "file" format should be identical to the result of > > > > capturing the socket data off the wire. ie just a concatenation > > > > of QMP commands, with no extra wrapping / change in format. > > > > > > > > > > Eugh. That's just so hard to parse, because there's no off-the-shelf > > > tooling for "load a sequence of JSON documents". Nothing in Python > > > does it. :\ > > > > It isn't that hard if you require each JSON doc to be followed by > > a newline. > > > > Feed one line at a time to the JSON parser, until you get a complete > > JSON doc, process that, then re-init the parser and carry on feeding > > it lines until it emits the next JSON doc, and so on. > > > > There's two interfaces in Python: > > (1) json.load(), which takes a file pointer and either returns a > single, complete JSON document or it raises an Exception. It's not > useful here at all. > (2) json.JSONDecoder().raw_decode(strbuf), which takes a string buffer > and returns a 2-tuple of a JSON Document and the position at which it > stopped decoding.
Yes, the latter would do it, but you can also be lazy and just repeatedly call json.loads() until you get a valid parse $ cat demo.py import json cmds = [] bits = [] with open("qmp.txt", "r") as fh: for line in fh: bits.append(line) try: cmdstr = "".join(bits) cmds.append(json.loads(cmdstr)) bits = [] except json.JSONDecodeError: pass for cmd in cmds: print("Command: %s" % cmd) $ cat qmp.txt { "execute": "qmp_capabilities" } { "execute": "blockdev-add", "arguments": { "node-name": "drive0", "driver": "file", "filename": "$TEST_IMG" } } { "execute": "blockdev-add", "arguments": { "driver": "$IMGFMT", "node-name": "drive0-debug", "file": { "driver": "blkdebug", "image": "drive0", "inject-error": [{ "event": "l2_load" }] } } } { "execute": "human-monitor-command", "arguments": { "command-line": "qemu-io drive0-debug \"read 0 512\"" } } { "execute": "quit" } $ python demo.py Command: {'execute': 'qmp_capabilities'} Command: {'execute': 'blockdev-add', 'arguments': {'node-name': 'drive0', 'driver': 'file', 'filename': '$TEST_IMG'}} Command: {'execute': 'blockdev-add', 'arguments': {'driver': '$IMGFMT', 'node-name': 'drive0-debug', 'file': {'driver': 'blkdebug', 'image': 'drive0', 'inject-error': [{'event': 'l2_load'}]}}} Command: {'execute': 'human-monitor-command', 'arguments': {'command-line': 'qemu-io drive0-debug "read 0 512"'}} Command: {'execute': 'quit'} > Wanting to keep the script easy to append to is legitimate. I'm keen > to hear a bit more about the use case here before I press extremely > hard in any given direction, but those are my impulses here. We can see examples of where this could be used in the I/O tests eg in tests/qemu-iotests/071, a frequent pattern is: run_qemu <<EOF { "execute": "qmp_capabilities" } { "execute": "blockdev-add", "arguments": { "node-name": "drive0", "driver": "file", "filename": "$TEST_IMG" } } { "execute": "blockdev-add", "arguments": { "driver": "$IMGFMT", "node-name": "drive0-debug", "file": { "driver": "blkdebug", "image": "drive0", "inject-error": [{ "event": "l2_load" }] } } } { "execute": "human-monitor-command", "arguments": { "command-line": 'qemu-io drive0-debug "read 0 512"' } } { "execute": "quit" } EOF Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|