[libvirt] [PATCHv2] xml: print uuids or shell-escaped names in the warning

[Jiri Denemark]

On Thu, Oct 25, 2012 at 16:37:37 +0200, Ján Tomko wrote:
> In the XML warning, this prints uuids for domain names with special
> characters in them and shell-escaped names for other elements (like
> snapshosts and networks) with special names.
> ---
> When saving snapshots, the domain name is appended to the
> "snapshot-edit" command, so using a domain name that needs escaping
> would lead to something that can't be just fed to the shell as it would
> glue them together.
> 
> diff to xml: shell-escape domain name in comment:
> - Domain names don't get escaped, UUIDs are preferred.
> - The command gets escaped too.
> 
> diff to v1: don't try to use CDATA (it doesn't belong there)
> ---
>  src/conf/domain_conf.c   |    6 +++-
>  src/libvirt_private.syms |    2 +
>  src/qemu/qemu_domain.c   |    3 +-
>  src/util/buf.c           |   66 ++++++++++++++++++++++++++++++++++++++++++++++
>  src/util/buf.h           |    1 +
>  src/util/xml.c           |   62 ++++++++++++++++++++++---------------------
>  src/util/xml.h           |    1 +
>  7 files changed, 109 insertions(+), 32 deletions(-)

I think we're making this too complicated for no real benefit. The goal is to
provide a hint to anyone who looks at the autogenerated XML files and IMHO
providing an escaped string (that would only work in environments for which it
was designed). I would just keep it simple:

- emit "virsh command name" in case name is nice
- emit "virsh command uuid" in case name is ugly and uuid is known
- emit "virsh command" in all other cases

This should keep the hints in domain and network XML files in /etc/libvirt
usable for copy&paste (the UUID fallback works there). Snapshot files (located
in /var/lib/libvirt) use "virsh snapshot-edit domain snapshot", where domains
are passed as part of the command and snapshots have no UUIDs. Thus to keep the
code simple, I'd emit just "virsh snapshot-edit", which is still a useful
hint and I don't believe we need to do anything beyond that.

Jirka