Libguestfs - Jan 2023 - [PATCH v2v] -o rhv-upload: Give a nicer error if the storage domain does not exist

https://bugzilla.redhat.com/show_bug.cgi?id=1986386

My RHV instance is dead at the moment so I didn't do much more than
check this compiles and passes the one test we have.  Also I want to
spend as little time as possible on RHV outputs for virt-v2v since the
RHV product will be discontinued soon.

I did want to point out some things:

 - The preceeding code is probably wrong.
  
https://github.com/libguestfs/virt-v2v/blob/master/output/rhv-upload-transfer.py#L70

   It attempts to search for the output storage using:

    storage_domains = system_service.storage_domains_service().list(
        search='name=%s' % params['output_storage'],
        case_sensitive=True,
    )

   I couldn't find any documentation about what can go into that
   search string, but it's clearly a lot more complicated than just
   pasting in the literal name after "name=".  At the very least,
   spaces are not permitted, see:
  
https://github.com/libguestfs/virt-v2v/blob/master/output/rhv-upload-transfer.py#L70

 - The bug reporter used "data*" as the name and I suspect that is
   parsed in some way (wildcard? regexp? I've no idea).

 - Probably for the same reason, the preceeding code ought to fail
   with an error if the output storage domain doesn't exist.  The fact
   we reach the code patched here at all also indicates some bug,
   maybe in the search string.

As I say above, I don't especially care about any of this.

Rich.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1986386
Reported-by: Junqin Zhou
---
 output/rhv-upload-precheck.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/output/rhv-upload-precheck.py b/output/rhv-upload-precheck.py
index 1dc1b8498a..35ea021032 100644
--- a/output/rhv-upload-precheck.py
+++ b/output/rhv-upload-precheck.py
@@ -81,7 +81,12 @@ datacenter = data_centers[0]
 
 # Get the storage domain.
 storage_domains = connection.follow_link(datacenter.storage_domains)
-storage_domain = [sd for sd in storage_domains if sd.name ==
params['output_storage']][0]
+try:
+    storage_domain = [sd for sd in storage_domains \
+                      if sd.name == params['output_storage']][0]
+except IndexError:
+    raise RuntimeError("The storage domain ?%s? does not exist" %
+                       params['output_storage'])
 
 # Get the cluster.
 clusters = connection.follow_link(datacenter.clusters)
-- 
2.39.0

On Thu, Jan 26, 2023 at 2:31 PM Richard W.M. Jones <rjones at redhat.com>
wrote:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1986386
>
> My RHV instance is dead at the moment so I didn't do much more than
> check this compiles and passes the one test we have.  Also I want to
> spend as little time as possible on RHV outputs for virt-v2v since the
> RHV product will be discontinued soon.
>
> I did want to point out some things:
>
>  - The preceeding code is probably wrong.
>   
https://github.com/libguestfs/virt-v2v/blob/master/output/rhv-upload-transfer.py#L70
>
>    It attempts to search for the output storage using:
>
>     storage_domains = system_service.storage_domains_service().list(
>         search='name=%s' % params['output_storage'],
>         case_sensitive=True,
>     )
I think the search is correct. This is explained in
https://bugzilla.redhat.com/1986386#c1
>    I couldn't find any documentation about what can go into that
>    search string, but it's clearly a lot more complicated than just
>    pasting in the literal name after "name=".  At the very least,
>    spaces are not permitted, see:
>   
https://github.com/libguestfs/virt-v2v/blob/master/output/rhv-upload-transfer.py#L70
True, search can be an expression.
>  - The bug reporter used "data*" as the name and I suspect that
is
>    parsed in some way (wildcard? regexp? I've no idea).
It is treated as glob pattern, also explained in comment 1.
>  - Probably for the same reason, the preceeding code ought to fail
>    with an error if the output storage domain doesn't exist.  The fact
>    we reach the code patched here at all also indicates some bug,
>    maybe in the search string.
>
> As I say above, I don't especially care about any of this.
I'm not working on RHV since August 2022. Adding Albert who is current
RHV storage maintainer.

Nir