Thanks for the reply Cedric, wrappers is a dir that I made similar to examples which wraps the libvirt c code. The reason why I am doing this is to simplify the usage of virConnectOpenAuth - it's arguments and callbacks from JavaScript. Using ffi, I am unable to create the right callbacks and have it pass the correct arguments. I also followed a different approach of having my wrappers turned into a shared object (.so) and linking libvirt.so as a dependency. My environment is esx requiring authentication. Much appreciated, Vik.

On Feb 21, 2014, at 12:19 AM, Cedric Bosdonnat <cbosdonnat@suse.com> wrote:

Hello Vik,

...

On Thu, 2014-02-20 at 15:14 -0800, vikhyath reddy wrote: Thanks for libvirt. It is a life saver. I am in the process of writing some custom wrappers for libvirt so that it can be easily accessed from nodejs using the nodejs-ffi interfacing (basically describes a way to convert nodejs to c calls). I did write the wrapper on the lines of the examples provided. But I am unable to see my new functions in the libvirt.so file (which nodejs interfacing needs). Which means that my wrappers under <libvirt>/wrappers/ are not getting into libvirt.so like the ones at <libvirt>/examples

I don't quite get what you are doing. Why would you need to modify libvirt to wrap it in a nodejs-based script? What is that libvirt/wrappers folder you are mentioning? there is no such thing in the libvirt repository.

From what I understood from the nodejs-ffi page, you should mostly write javascript code similar to this:

------------ %< ------------

var ref = require('ref'); var ffi = require('ffi');

var virConnect = ref.types.void; var virConnectPtr = ref.refType(virConnect);

var libvirt = ffi.Library('libvirt', { 'virInitialize': [ 'int', [ ] ], 'virConnectOpen': [virConnectPtr, [ string ]], ... });

------------ %< ------------

I'm pretty sure generating this could be automated by a small program or script or even a clang plugin, using include/libvirt/libvirt.h.in as input.

...

Can you please guide me as to where I am going wrong? I was able to do a successful configure + make and I thought this will regenerate the new libvirt.so (which it does, but I cant see my new wrapper methods in it).

I case you really want to modify libvirt, then you should proceed as mentioned on this page:

http://libvirt.org/compiling.html

Regards, -- Cedric

Thanks for the replies guys, libvirt-glib sure sounds interesting. On the other hand I was able to leave libvirt.so alone and write my own wrapper (based on libvirt/examples) for easy calls from NodeJS. I can get to list VMs, their config etc. from node but not able to list the operating system running on the VM (ubuntu, win7, etc.). I can get the os_type though (hvm in my case) but that does not tell me whether it is running a windows or a linux distro. On Mon, Feb 24, 2014 at 5:00 AM, Christophe Fergeau <cfergeau@redhat.com>wrote:

Hey,

On Fri, Feb 21, 2014 at 07:30:08AM -0800, Vikhyath Reddy wrote:

...

Thanks for the reply Cedric,

wrappers is a dir that I made similar to examples which wraps the libvirt c code. The reason why I am doing this is to simplify the usage of virConnectOpenAuth - it's arguments and callbacks from JavaScript. Using ffi, I am unable to create the right callbacks and have it pass the correct arguments.

Depending on what parts of libvirt API you need to use from javascript, libvirt-glib may be an option as it already makes some parts of libvirt API accessible from javascript, see

http://libvirt.org/git/?p=libvirt-glib.git;a=blob;f=examples/conn-test.js;h=... for example. I don't know if this would be usable from nodejs? If this is a good fit for what you need, patches extending the libvirt API wrapped by libvirt-glib are very welcome ;)

Christophe

Libvirt can't tell you what the guest is running. For that, you need higher-level software, such as libguestfs. virt-manager is an example of a program that uses libguestfs to probe which OS is running in the guest.

Awesome! you guys are of so much help. And sorry for top posting. Ran into something else today, why are calls like a) virConnectListAllNetworks(...) b) virConnectListAllStoragePools(...) return "not supported by connection driver". I am running ESX with libvirt-1.2.1. But I can use a) virConnectListStoragePools(...) b) virConnectListNetworks(...) without any problems. Do you guys think I have libvirt configured incorrectly at my end? Thanks, Vik. On Mon, Feb 24, 2014 at 6:03 PM, Eric Blake <eblake@redhat.com> wrote:

On 02/24/2014 05:09 PM, vikhyath reddy wrote:

[Please don't top-post on technical lists]

...

Thanks for the replies guys, libvirt-glib sure sounds interesting. On the other hand I was able to leave libvirt.so alone and write my own wrapper (based on libvirt/examples) for easy calls from NodeJS. I can get to list VMs, their config etc. from node but not able to list the operating system running on the VM (ubuntu, win7, etc.). I can get the os_type though (hvm in my case) but that does not tell me whether it is running a windows or a linux distro.

Libvirt can't tell you what the guest is running. For that, you need higher-level software, such as libguestfs. virt-manager is an example of a program that uses libguestfs to probe which OS is running in the guest.

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