Fix Rocky container sed formatting

[Alex-Welsh]

Whitespace in the cloud.cfg file could previously cause the sed to fail, preventing the image from booting properly:

[   12.623671] cloud-init[966]: 2024-03-27 09:48:06,919 - util.py[WARNING]: Failed loading yaml blob. Invalid format at line 102 column 5: "while parsing a block mapping
[   12.626039] cloud-init[966]:   in "<unicode string>", line 102, column 5:
[   12.627229] cloud-init[966]:         renderers: ['network-manager']
[   12.628358] cloud-init[966]:         ^
[   12.629054] cloud-init[966]: expected <block end>, but found '<block mapping start>'
[   12.630460] cloud-init[966]:   in "<unicode string>", line 103, column 7:
[   12.631628] cloud-init[966]:           activators: ['network-manager']

[markgoddard]

Can you provide an example of the rendered output with some context?

[Alex-Welsh]

What the line is meant to do is edit /etc/cloud/cloud.cfg from something like this

foo:
   network:
      renderers: ['network-manager', 'some-other-options', 'more-options']

to:

foo:
   network:
      renderers: ['network-manager']
      activators: ['network-manager']   

But for some reason it breaks with the above error. My theory was that the solution wasn't working because it has a precise amount of whitespace in the sed command, so if the formatting of the source file is slightly changed it no longer is valid yaml. For example:

foo:
  network:
    renderers: ['network-manager']
      activators: ['network-manager']   

My solution instead edits it like this:

foo:
   network:
      {renderers: ['network-manager'], activators: ['network-manager'] }   

Which is valid yaml that no longer relies on whitespace.

Now all that being sed, I've since discovered that this element is breaking the Rocky 8 builds, and there has been a change to the upstream version here so rather than making similar changes for rocky 8, I was just going to try switching back to that upstream one and dropping this element entirely.

[markgoddard]

Now all that being sed

Appreciate this hidden pun.