libvirt users - Sep 2013 - Help needed in simulating libvirt

Hi All,
   I'm need to simulate libvirt API's say to mock the libvirt API
responses. (Actually I need to simulate qemu API's response). Because of my
project needs I need to write this simulated libvirt server in Java. I
believe the simulated libvirt can be written as java RPC which should
capable to receive the client RPC request calls and by dispatcher we can
dispatch to the simulated java functions. I searched for .x file to be used
for generating server stubs but unfortunately .x files like
"remote_protocol.x", "virnetprotocol.x",
"qemu_protocol.x" and
"lxc_monitor_protocol.x" are not containing any procedure for libvirt
API's
that exposed. Please let me know which files will have these exposed
procedures and how can I use it in java,

         Also I'm not sure how to implement the ssl layer support for the
libvirt server in java. I need to write a java server in such a way that
python client should capable to create a connection with uri
"qemu+tls://systemip:port?no_tty=1". Also with the created connection
object it should able to call the libvirt API's like getCapabilities, etc.

Any help and ideas on this will be really helpful.

Thanks in Advance,
Arun V

On 09/10/2013 12:03 PM, Arun Viswanath wrote:
> Hi All,
>    I'm need to simulate libvirt API's say to mock the libvirt API
> responses. (Actually I need to simulate qemu API's response). Because
of my
> project needs I need to write this simulated libvirt server in Java. I
> believe the simulated libvirt can be written as java RPC which should
> capable to receive the client RPC request calls and by dispatcher we can
> dispatch to the simulated java functions. I searched for .x file to be used
> for generating server stubs but unfortunately .x files like
> "remote_protocol.x", "virnetprotocol.x",
"qemu_protocol.x" and
> "lxc_monitor_protocol.x" are not containing any procedure for
libvirt API's
> that exposed. Please let me know which files will have these exposed
> procedures and how can I use it in java,
Rather than trying to write your own RPC handler, have you considered
using the existing libvirt-java bindings and just targetting the
test:/// URI connection?  This will give you a fairly reliable exposure
to the libvirt APIs, without actually needing a working qemu.

The .x files implement the driver API; so also does the test driver.
Basically, src/libvirt.c is the public API, which then delegates to the
appropriate driver based on what URI you connected to; if the URI is
remote (as qemu:/// and all other stateful drivers are), then libvirt.so
passes it to src/remote/remote_driver.c to be bundled up into RPC calls
which mirror the semantics of the public API.  If you want to install
your own mock driver, it may be easier to build a new URI and implement
the same C interface as the test driver (see src/test/test_driver.c)
than it is to implement your own RPC parser.
> 
>          Also I'm not sure how to implement the ssl layer support for
the
> libvirt server in java. I need to write a java server in such a way that
> python client should capable to create a connection with uri
> "qemu+tls://systemip:port?no_tty=1". Also with the created
connection
> object it should able to call the libvirt API's like getCapabilities,
etc.
Again, instead of trying to write your own RPC server, I'd instead focus
on utilizing the existing test:/// driver as your point of mocked calls.

As this is mostly development-related, I've set the reply-to to
libvir-list (we can drop libvirt-users from the rest of this thread).

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

Hi Eric,

Thanks for your response.
I like to know how test driver works.

In the libvirt.org for test driver it is mentioned as "It can start with a
pre-configured default config, or be given a path to an alternate config".
Is the config is an xml file where we mentioned some dummy data so that the
test driver will return it as response. If yes then where can I find this
dummy file?

As mentioned earlier my intention is to mock qemu calls. so it test driver
works then I'm planning to remove the qemu driver and register
"test"
driver as "qemu" driver and take the fake data from the config file.
Please
let me know which are the files I need to look into to register "test"
as
"qemu" and make its operations to work.

Thanks In Advance,
Arun V


On Wed, Sep 11, 2013 at 12:14 AM, Eric Blake <eblake@redhat.com> wrote:
> On 09/10/2013 12:03 PM, Arun Viswanath wrote:
> > Hi All,
> >    I'm need to simulate libvirt API's say to mock the libvirt
API
> > responses. (Actually I need to simulate qemu API's response).
Because of
> my
> > project needs I need to write this simulated libvirt server in Java. I
> > believe the simulated libvirt can be written as java RPC which should
> > capable to receive the client RPC request calls and by dispatcher we
can
> > dispatch to the simulated java functions. I searched for .x file to be
> used
> > for generating server stubs but unfortunately .x files like
> > "remote_protocol.x", "virnetprotocol.x",
"qemu_protocol.x" and
> > "lxc_monitor_protocol.x" are not containing any procedure
for libvirt
> API's
> > that exposed. Please let me know which files will have these exposed
> > procedures and how can I use it in java,
>
> Rather than trying to write your own RPC handler, have you considered
> using the existing libvirt-java bindings and just targetting the
> test:/// URI connection?  This will give you a fairly reliable exposure
> to the libvirt APIs, without actually needing a working qemu.
>
> The .x files implement the driver API; so also does the test driver.
> Basically, src/libvirt.c is the public API, which then delegates to the
> appropriate driver based on what URI you connected to; if the URI is
> remote (as qemu:/// and all other stateful drivers are), then libvirt.so
> passes it to src/remote/remote_driver.c to be bundled up into RPC calls
> which mirror the semantics of the public API.  If you want to install
> your own mock driver, it may be easier to build a new URI and implement
> the same C interface as the test driver (see src/test/test_driver.c)
> than it is to implement your own RPC parser.
>
> >
> >          Also I'm not sure how to implement the ssl layer support
for the
> > libvirt server in java. I need to write a java server in such a way
that
> > python client should capable to create a connection with uri
> > "qemu+tls://systemip:port?no_tty=1". Also with the created
connection
> > object it should able to call the libvirt API's like
getCapabilities,
> etc.
>
> Again, instead of trying to write your own RPC server, I'd instead
focus
> on utilizing the existing test:/// driver as your point of mocked calls.
>
> As this is mostly development-related, I've set the reply-to to
> libvir-list (we can drop libvirt-users from the rest of this thread).
>
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>
>