Re: [PATCH] check: force hostname to be unique

[Luis Chamberlain <mcgrof@kernel.org>]

On Wed, Jan 16, 2019 at 04:12:12PM +0800, Eryu Guan wrote:
> On Fri, Jan 11, 2019 at 01:54:20PM -0800, Luis Chamberlain wrote:
> > If you use a hostname which is part of the output of
> > standard tools you end up with failures with fstests
> > due to differences in output against the golden output.
> > 
> > The failures are false positives due to the hostname.
> > For instance if you hostname is 'xfs' _dump_filter_main()
> > will substitute the initiial 'xfs' with HOSTNAME as part
> > of your logs, and will fail the output will fail against
> > the golden output on say all xfsdump / xfsrestores tests.
> > 
> > The hostname must be a unique string, not used as part
> > of the output from any tool used when capturing output.
> > 
> > Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> 
> IMHO, a better fix would be improving the regexp in _dump_filter_main to
> match hostname more precisely. I did the following update and it seemed
> to work fine, I tested with '-g dump' and all tests passed (some tests
> _notrun due to missing tape device).
> 
> --- a/common/dump
> +++ b/common/dump
> @@ -826,7 +826,8 @@ _dump_filter_main()
>        -e "s#$__XFSDUMP_PROG#xfsdump#"                  \
>        -e "s#$XFSRESTORE_PROG#xfsrestore#"              \
>        -e "s#$XFSINVUTIL_PROG#xfsinvutil#"              \
> -      -e "s/`hostname`/HOSTNAME/"                      \
> +      -e "s/`hostname`:/HOSTNAME:/"                    \
> +      -e "s/: `hostname`/: HOSTNAME/"                  \
>        -e "s#$SCRATCH_DEV#SCRATCH_DEV#"                 \
>        -e "s#$SCRATCH_RAWDEV#SCRATCH_DEV#"              \
>        -e "s#$dumptape#TAPE_DEV#"                       \
> 
> It's based on the fact that there're basically two patterns that contain
> 'HOSTNAME':
> 
> xfsrestore: hostname: HOSTNAME
> xfsdump: level 0 dump of HOSTNAME:SCRATCH_MNT

Works for me but this is still pretty fragile, and it does not cover
the what other filesystems use as best-practices for issuign a hostname
either. Even if we consider xfs: are we *certain* that the above regexp
covers all output issued by xfs utils when hostname is used? We're
talking about a generic rule of thumb here.

So I'd say we do both for now. Just my 0.01 CRC.

  Luis