providers: support for vendor-data in proxmoxve

[jdoss]

This PR adds support for reading Ignition data out of the vendor-data file so we can leave the cloud-config in the user-data file. It will always use the user-data file if it has an ignition config over using the vendor-data file.

This works as expected:

# /home/jdoss/ignition --platform proxmoxve --stage fetch -log-to-stdout
INFO     : Ignition v2.10.1-1315-gaf19b7d7-dirty
INFO     : Stage: fetch
INFO     : no config dir at "/usr/lib/ignition/base.d"
INFO     : no config dir at "/usr/lib/ignition/base.platform.d/proxmoxve"
DEBUG    : parsed url from cmdline: ""
INFO     : no config URL provided
INFO     : reading system config file "/usr/lib/ignition/user.ign"
INFO     : no config at "/usr/lib/ignition/user.ign"
DEBUG    : creating temporary mount point
INFO     : op(1): [started]  mounting config drive
DEBUG    : op(1): executing: "mount" "-o" "ro" "-t" "auto" "/dev/disk/by-label/cidata" "/tmp/ignition-configdrive2469853404"
INFO     : op(1): [finished] mounting config drive
DEBUG    : config drive ("/tmp/ignition-configdrive2469853404/user-data") contains a cloud-config configuration, ignoring
DEBUG    : config drive ("/tmp/ignition-configdrive2469853404/vendor-data") contains a ignition configuration
INFO     : op(2): [started]  unmounting "/dev/disk/by-label/cidata" at "/tmp/ignition-configdrive2469853404"
INFO     : op(2): [finished] unmounting "/dev/disk/by-label/cidata" at "/tmp/ignition-configdrive2469853404"
DEBUG    : parsing config with SHA512: d45cc6bd9291debbfbd47365a802208a027b77407d39caf42f873ffd9183cc20dbc01803da2c17cfba09e1c753bff9168a5865bff30f9428088ae7f7b87d7ae0
INFO     : fetch: fetch complete
INFO     : fetch: fetch passed
INFO     : Ignition finished successfully

[jlebon]

One more comment, otherwise LGTM.

Can you squash all your commits into the first?

[jdoss]

Feedback applied and commits squashed.

[prestist]

Small nits; lgtm

For the commit message I think it might sound clearer if we remove the details about the pr.

wdyt about

"Add support for reading Ignition data out of the
vendor-data file. No longer clobber the user-data file."

?

[jdoss]

Feedback applied. Please let's merge this. :)

[prestist]

Thank you, I am trying to work through the failing CI. Locally having some issues with golang so it might take me a few moments.

[prestist]

deviceLabel = "cidata" needs some spaces gofmt is not allowing builds.

You can fix this by running gofmt on the proxmoxve file.