8:21 p.m.
On Fri, Nov 14, 2014 at 04:24:17PM -0500, Nir Soffer wrote:
> >>
> >> Hi everyone,
> >>
> >> the recent JSONRPC discussion and my last work around vdsClient reminded
> >> me
> >> that
> >> since a long time there it was vague plans for a vdsClient overhaul
> >>
> >> or at least I haven't ever found a detailed plan :)
> >>
> >> Since we have to add jsonrpc support anyway, it could be a good chance to
> >> bootstrap
> >> a new vdsClient, and incrementally enhance it as needs arises; the old
> >> vdsClient will
> >> not go away very soon, I guess.
> >>
> >> At least, we can to put together a wishlist for a new vdsClient and add it
> >> to
> >> the wiki.
> >>
> >> My one, so far:
> >> * client library package: we should have a program-friendly python package
> >> to
> >> access
> >> VDSM, in order
> >> * JSON for input: I's like to open logs, grab a line including a
command
> >> and
> >> feed
> >> vdsClient with the very same line
> >
> > Currently we don't see commands json input in the logs, but this can be a
> > good
> > idea (in debug mode).
> >
> > +1
> >
> > JSON for output: current vdsClient format replies in a mix of text and
> > json. We
> > need to print the json returned from vdsm as is.
but a pretty-printed output can be useful, too.
> >
>
> I started discussion about it and here is what I was able to gather:
> - we should start new vdsClient like tool which holds current vdsClient
> command line interface.
> - vdsClient should stay as it is and we can extend new client with additional
> functionality as we need (adding debug mode etc)
Current vdsClient horrible - we need to replace it with something better.
and never look back. it's beyond redemtion.
- The interface is not consistent, trying to convert command line options to
xmlrpc call
- Error handling is not helpful, showing an error message and then printing
help for all verbse, so the error message is hidden above your screen
- Help message is not useful, we need only the names of the parameters
- We need extended help for specific verb - like "git help commit"
- Command output is not consistent and unusable for parsing in scripts
We need to print the returned value from vdsm as is, or prety printed.
> - there was a suggestion to reuse ovirt-engine-cli ideas and it should
> use schema
> to determine the API
Using the schema can be nice to generate help for the commands.
I started a simple jsonrpc client that can be used for testing *now*:
http://gerrit.ovirt.org/35181
Example usage:
Calling method without arguements:
# jsonrpc Host.getVMList
{
"jsonrpc": "2.0",
"id": "0e043d83-294a-4d31-b1b6-6dc2f2747494",
"result": [
"b3f6fa00-b315-4ad4-8108-f73da817b5c5"
]
}
Calling method with arguements:
# jsonrpc VM.getStats '{"vmID":
"b3f6fa00-b315-4ad4-8108-f73da817b5c5"}'
{
"jsonrpc": "2.0",
"id": "cefd25a3-6250-4123-8a56-d7047899e19e",
"result": [
{
"status": "Down",
"exitMessage": "Admin shut down from the engine",
"vmId": "b3f6fa00-b315-4ad4-8108-f73da817b5c5",
"exitReason": 6,
"timeOffset": "0",
"exitCode": 0
}
]
}
Thanks, this looks very nice and ready for contrib, imho.
I'd love to see something similar done to make vdscli connect over
jsonrpc. When I need to do something less than trivial from the command
line, I start python and
from vdsm import vdscli
s = vdscli.connect() # does a horribly useful heuristic, to connect
# to local host over xmlrpc
print s.getVMList()
I'd like to see vdscli.connect() extended to jsonrpc. This would
simplify
Bug 1112594 - Use jsonrpc during migration of vms
too.
Dan.