[Ovirt-devel] [PATCH node-image] avoid image-minimizer fall-out

[Daniel P. Berrange]

On Wed, Oct 08, 2008 at 03:08:50PM +0200, Jim Meyering wrote:
> 
> >From 8e45eb82fb7ed450de78e48aeaa8bd34b04313e1 Mon Sep 17 00:00:00 2001
> From: Jim Meyering <meyering at redhat.com>
> Date: Wed, 8 Oct 2008 14:59:31 +0200
> Subject: [PATCH node-image] ovirt-node-image.ks (%post): Include common-post.ks last
> 
> I noticed the following error go by today:
> 
>     Removing blacklisted files and directories
>     Cleanup empty directory structures in /usr/share
>     Running image-minimizer...
> ==> Unknown Command: touch

The image minimiser should immediately exit with non-zero status
upon errors, not merely print a warning which could be missed in
the line noise for months.

>     e2fsck 1.41.0 (10-Jul-2008)
>     Pass 1: Checking inodes, blocks, and sizes
> 
> That's due to the new use of image-minimizer in common-post.ks (cool, btw!).
> It appears at the end of that file:
> 
>     echo "Cleanup empty directory structures in /usr/share"
>     find /usr/share -type d -exec rmdir {} \; > /dev/null 2>&1
> 
>     echo "Running image-minimizer..."
>     %post --nochroot --interpreter image-minimizer
>     drop /usr/lib/libboost*
>     keep /usr/lib/libboost_program_options.so*
>     keep /usr/lib/libboost_filesystem.so*
>     drop /usr/lib64/libboost*
>     keep /usr/lib64/libboost_program_options.so*
>     keep /usr/lib64/libboost_filesystem.so*
> 
> However, common-post.ks is included from ovirt-node-image.ks like this:
> 
>     ...
>     %post
>     %include common-post.ks
> 
>     touch /.autorelabel
> 
>     %end
> 
> Which means the "touch" command is interpreted by image-minimizer.
> Whoops.
> 
> The patch below fixes that by moving the "touch" to precede the
> inclusion of common-post.ks:
> ---
>  ovirt-node-image.ks |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/ovirt-node-image.ks b/ovirt-node-image.ks
> index f5695d8..36b5da9 100644
> --- a/ovirt-node-image.ks
> +++ b/ovirt-node-image.ks
> @@ -8,10 +8,13 @@
>  %end
> 
>  %post
> -%include common-post.ks
> 
>  touch /.autorelabel
> 
> +%include common-post.ks
> +# CAUTION: don't include anything between the inclusion of common-post.ks
> +# and the "%end" directive below.  Since the tail of common-post.ks invokes
> +# image-minimizer, anything here would be interpreted as commands to it.


How about instead, adding another  '%post' at the end of the 'common-post.ks'
script, so that it resets things back to being processed by 'sh', instead
of the image-minimizer. 

If an include file changes semantics for a period, it is good practice to
restore the original semantics to avoid these kind of surprises.

Daniel
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