new script ch-convert

[reidpr]

This PR implements a new script ch-convert that replaces the following scripts, which are now deprecated:

• ch-build2dir
• ch-builder2squash
• ch-builder2tar
• ch-dir2squash
• ch-pull2dir
• ch-pull2tar
• ch-tar2dir

Relevant to #484.

[shanegoff]

I think everything looks good here.

[reidpr]

Need to take care with unsquashfs(1) options to avoid:

Parallel unsquashfs: Using 64 processors
20198 inodes (23645 blocks) to write
 
 
write_xattr: could not write xattr security.selinux for file /var/tmp/ior-openmpi-at/bin because you're not superuser!
 
write_xattr: to avoid this error message, either specify -user-xattrs, -no-xattrs, or run as superuser!
 
Further error messages of this type are suppressed!
[=============================================================================================- ] 23644/23645  99%
 
created 17960 files
created 2059 directories
created 2020 symlinks
created 0 devices
created 0 fifos

Thanks for catching this @atorrez and @Brofessional!

[shanegoff]

I like the new approach. I'm sure I'll mess up the formats every time trying to do implicit so I'm happy about the explicit options, it looks a little more the way I'd be used to exporting images.

I am totally unreasonably opposed to adding other output extensions for squashfs. No strong reason, it just makes output extensions more complicated.

down with .squash and .squashfs long live .sqfs

[j-ogas]

Looks good. Are we still planning to add the conveniece subcommand ch-image convert? If so we should also add the documentation draft for that here as well.

[reidpr]

Are we still planning to add the conveniece subcommand ch-image convert?

Yes, though I think it would be three subcommands: dir, tar, squash. I was thinking that would be a separate PR though. What's your argument it should be included here?

[j-ogas]

Yes, though I think it would be three subcommands: dir, tar, squash. I was thinking that would be a separate PR though. What's your argument it should be included here?

Ah, three explicit subcommands sounds like a better approach. In that case, yes, a separate PR seems appropriate.

[shanegoff]

Overall I think everything is working as intended. Only a few small things here and there that I thought were maybe confusing in the documentations.

[reidpr]

More to-do:

• re-check docs for deprecated scripts post merge of PR ch-run: auto-mount squashfs #1102

[shanegoff]

This looks great. I look forward to the one wrapper to rule them all.

[j-ogas]

LGTM!