Support compressed source images ("http://domain/image.qcow2.gz")

[sergelogvinov]

Description

Currently you can use only raw source images

images:
- location: "http://domain/image.qcow2"
  arch: "x86_64"
  digest: "sha512:123123"

Sometimes OS distributive does not have unarchived images on the website. It will be nice to have such capabilities to use archived source images.

[AkihiroSuda]

What is "archived source images"?

[sergelogvinov]

What is "archived source images"?

Fo example: the source image gzipped or used another archive algorithm.

like this:

- location: "http://domain/image.qcow2.gz"

[afbjorklund]

That is normally called compressed images (like .gz or .xz), where "archive" is normally reserved for something like .tar or .zip

Being able to automatically decompress would be a nice feature

[sergelogvinov]

What do you think about https://github.com/mholt/archiver module.

the workflow will be:

• download file and check checksum
• decompress the file if extension of file is "known compression format"
• pass to next steps

[AkihiroSuda]

What do you think about https://github.com/mholt/archiver module.

Looks overloaded.
Having a built-in support for gzip and maybe zstd is fine, but I'd prefer to use os/exec for other minor formats.

[afbjorklund]

Flatcar still uses the legacy .bz2 format, as well