Re: [Qemu-devel] [PATCH] This patch adds a new block driver : iSCSI

[Daniel P. Berrange]

On Thu, Oct 13, 2011 at 08:46:54PM +1100, ronnie sahlberg wrote:
> Previous version of the patch received very positive feedback and
> several expressed seeing positive value of a built-in initiator.
> I updated patch from feedback 3 weeks ago and Stefan kindly reviewed it.
> 
> 
> Is there some other problem with the patch I am not aware of that I
> should address?
> 
> I have been trying to push this patch in different versions since
> December last year.
> There is obviously a problem here I am not aware of.
> Please advice what the problem is and I will try to rectify it.
> 
> 
> Please advice on how I can move forward. I feel a bit at roads end
> here. Please help.

I can't comment much on the code, but I'm supportive of QEMU gaining
this feature, because it addresses a number of use cases not satisfied
by using iSCSI via the host OS's block layer.


> >>> You can specify devices using a iscsi url of the form :
> >>> iscsi://[<username>[:<password>@]]<host>[:<port]/<target-iqn-name>/<lun>
> >>> When using authentication, the password can optionally be set with
> >>> LIBISCSI_CHAP_PASSWORD="password" to avoid it showing up in the process 
> >>> list

I'm not a fan of sending passwords via command line args, or
environment variables.  Env variables *can* be exposed via
the process list, albeit not to unprivileged users. More
critically, env variables will end up in logfiles like
/var/log/libvirt/qemu/$GUESTNAME.log, and in data reported
to distro bug trackers, via tools like sosreport which
capture /proc/$PID/environ and aforementioned logfiles.

We have a similar requirement for specifying passwords with
the Ceph/RBD driver, and also for the curl/HTTP block drivers.
We have a monitor command for providing decryption passwords for
QCow2 disks. We could either reuse that for connection passwords,
or perhaps slightly better would be to have a separate command
for connection passwords.


Daniel
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