Add support for latest compression via min-os-version

[YesThatAllen]

I was creating a large pkg, and my go-to tooling doesn't support Apple's "new" compression options.

I read about "This one weird Monterrey trick" and added it to munki-pkg.

I am not sure that there would be differences in workflows by setting 10.5 & legacy, but this does change default behavior by adding two keys, even if not defined by the user. I set the defaults so as not to interrupt any workflows.

In my project file, I set them to min-os-version 10.10 and compression to latest, the resulting .pkg was 31MB vs 49MB.

[erikng]

Awesome. Can't wait to try this out.

[gregneagle]

So do!

[erikng]

It's always funny knowing what you'll say as I type things. :)

[gregneagle]

Also: do we know when these options were added to pkgbuild? If fairly recently we may want to check we're running under a recent-enough macOS version.

[gregneagle]

@scriptingosx sez the --compression option was added in macOS 12.0 so I think we need to check for that as well. I don't need a bunch of support requests from admins trying to use these options on Big Sur or earlier. The code should guide them, not me :-)

[YesThatAllen]

I'm not gonna say I'm done, but at this point the tooling allows for min-os-version/compression without trying to enforce or auto-add the related keys.

I was looking at what it would take to auto-discover the settings in an existing package during --import when I hit something interesting:

% ./munkipkg --import path/to/compressed.pkg newpkgtest
ditto: cpio read error: bad file format
ERROR: Ditto failed to expand Payload

and the newpkgtest folder looks like

ls -al newpkgtest
total 65768
drwxr-xr-x   7 ahancock  wheel       224 Apr  4 19:56 .
drwxr-xr-x  14 ahancock  wheel       448 Apr  4 19:56 ..
-rw-r--r--   1 ahancock  wheel   1157317 Apr  4 19:56 Bom.txt
-rw-r--r--   1 ahancock  staff      1219 Apr  4 19:56 Distribution
-rw-r--r--   1 ahancock  staff      1076 Apr  4 19:56 PackageInfo
-rw-r--r--   1 ahancock  staff  31997300 Apr  4 19:55 Payload.cpio.gz
drwxr-xr-x   2 ahancock  wheel        64 Apr  4 19:56 payload

Another part of this project might be to add support for decompressing the newer style of Payload.cpio.gz. Maybe in a different issue/PR, but I wanted to at least stop & document where I was at.

[YesThatAllen]

The more I think about this, adding decoding of the newer cpio.gz feels like a separate issue (and of questionable priority)

Improvements to this PR which I can think of include:

• Detecting the OS being used & auto-preventing --min-os-version
• more validation for --min-os-version (regex for 1*.* ?)
• validating that --compression can't be used without --min-os-version

However, it's probably more than needed, and pkgbuild will give appropriate scolding if the commands are used out of turn.

in other words, I think this PR is ready for more tire kicking/feedback.

[YesThatAllen]

I've got a need to reference this branch soon, bumping this PR to see if changes are needed, and if it can be merged. thanks!

[erikng]

Would be awesome to get this merged.

Similar to https://github.com/autopkg/autopkg/pull/905

[loceee]

I haven't invested much time into troubleshooting, but my baseline vms in my pkging pipeline is still on 12.x - this PR now throws:

pkgbuild: Inferring bundle components from contents of /Users/Shared/build/tmp_googlechrome.GaWXx7/googlechrome/payload
pkgbuild: Writing new component property list to /tmp/tmp5qu8ih9u/component.plist
munkipkg: Turning off bundle relocation for Applications/Google Chrome.app
Traceback (most recent call last):
  File "/Users/Shared/resources/munki-pkg/munkipkg", line 1312, in <module>
    main()
  File "/Users/Shared/resources/munki-pkg/munkipkg", line 1308, in main
    result = build(arguments[0], options)
  File "/Users/Shared/resources/munki-pkg/munkipkg", line 917, in build
    build_pkg(build_info, options)
  File "/Users/Shared/resources/munki-pkg/munkipkg", line 620, in build_pkg
    if build_info['compression']:

I assume this change now drops support for for macOS12.x - which is totally reasonable.

[gregneagle]

No, that looks like a bug to me.

[gregneagle]

Addressed here: https://github.com/munki/munki-pkg/commit/73bc0fd7e70aef3a7db27183064641b2dd62059e