[Libvir] Preliminary patch to support remote driver / libvirtd (updated: 20070213)

[Richard Jones]

Attached is the latest rev of this patch to support remote drivers.   
It is
still not in a state where it can or should be applied.  In  
particular it
still "does nothing" except supporting the version and type calls.

Changes:

  * The URL syntax has changed.  Please see the first attachment for
    complete details of the new syntax.
  * Attempts to verify client IP address using TLS certificate, but
    this code is probably not correct.
  * libvirtd has a comprehensive configuration file.
  * libvirtd forks into the background, and has many other improvements.
  * All previous comments that I received should have been taken into
    account and where possible fixed.  Please let me know if there's
    anything I've missed.

Some things to discuss
----------------------

Should libvirt clients automatically reconnect when the server  
(libvirtd)
restarts?  SunRPC supports this, reasonably seamlessly.  The problem is
that we will be issuing a "cookie" to the client to represent various
structures held on the server (mainly virConnectPtr, but also  
virDomainPtr
and a few others).  The mapping of cookie -> structure is lost when
libvirtd restarts unless we keep it somewhere persistent.  Now if we
keep track of cookie -> URLs in a persistent place, then when a client
represents a cookie that we don't know about because it was created in
a previous libvirtd session, we can look it up and reopen the connection
to the backend (using the URL).  In the current implementation of  
libvirt
this looks safe.

Should libvirtd run as a preforked server?  SunRPC is basically single
threaded.  The server handles one RPC at a time and processes it to
completion before handling the next.  The simple way around this is to
use a preforked server.  This has implications with cookies -- either
they need to be stored in shared memory (similar to Apache's scoreboard
stuff) or else in persistent storage.

		-		-		-

The second attachment is the patch.  You can also download the patch
from http://www.annexia.org/tmp/libvirt-tls-20070213.patch

-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: urls.txt
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20070213/c782e250/attachment-0001.txt>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: libvirt-tls-20070213.patch
Type: application/octet-stream
Size: 144292 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20070213/c782e250/attachment-0001.obj>