[libvirt] [PATCH 1/2] tests: Support for faking emulator in qemuxml2argv

[Eric Blake]

On 12/01/2010 07:56 AM, Jiri Denemark wrote:
> This patch allows for using custom scripts instead of /usr/bin/qemu
> emulator in domain XML. To do so, one would specify relative path to the
> custom script in <emulator/>. The path needs to be relative to
> qemuxml2argvdata directory and it will be transparently made absolute in
> runtime. The expected command line needs to contain the exact relative
> path as was used in domain XML.

Makes sense as a testing mechanism, while still something we do not want
exposed to normal usage.

> 
> The problem is RelaxNG schema for domain XML only allows for absolute
> path within <emulator/>. To workaround it, an extra '/' must be added at
> the beginning of the path. That is, instead of "./qemu.sh" or
> "../emulator/qemu.sh" one would use "/./qemu.sh" or
> "/../emulator/qemu.sh". The extra slash is removed before further
> processing. I don't like this workaround, it's very ugly but it's the
> best option I was able to come up with. Relaxing domain XML schema is
> not an option IMO.

Agreed - relaxing the schema would leak the notion of a relative
emulator path, which we don't want to do.  The hack looks as good as any
to me, as long as it's well documented in the code as well as the commit
message.

> ---
>  tests/qemuxml2argvtest.c |   18 ++++++++++++++++++
>  1 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
> index e6174be..dd07001 100644
> --- a/tests/qemuxml2argvtest.c
> +++ b/tests/qemuxml2argvtest.c
> @@ -41,6 +41,7 @@ static int testCompareXMLToArgvFiles(const char *xml,
>      virDomainChrDef monitor_chr;
>      virConnectPtr conn;
>      char *log = NULL;
> +    char *emulator = NULL;
>  
>      if (!(conn = virGetConnect()))
>          goto fail;
> @@ -52,6 +53,16 @@ static int testCompareXMLToArgvFiles(const char *xml,
>                                          VIR_DOMAIN_XML_INACTIVE)))
>          goto fail;
>  
> +    if (vmdef->emulator && STRPREFIX(vmdef->emulator, "/.")) {
> +        if (!(emulator = strdup(vmdef->emulator + 1)))

In other words, I'd add a comment here explaining that for test purposes
only, we massage particular emulator names.

ACK, with that nit addressed.

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 619 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20101201/96722f15/attachment-0001.sig>