schema: add json for modules K-L

[blackboxsw]

Proposed Commit Message

schema: add JSON defs for modules K-L

Includes:
- cc_keyboard: migrated legacy scheme to cloud-init-schema.json
- cc_keys_to_console:
- cc_landscape: added schema defs for most frequent client keys
- cc_locale
- cc_lxd

Dropping duplicates docs as schema examples now cover them
 - doc/examples/cloud-config-landscape.txt 
 - doc/examples/cloud-config-lxd.txt 

LP: #1858899, #1858900, #1858901, #1858902

Additional Context

Test Steps

tox -e py3 tests/unittests/config
tox -e doc
xdg-open doc/rtd_html/topics/modules.html
for mod in cc_locale cc_lxd cc_landscape cc_keyboard cc_keys_to_console; do
    PYTHONPATH=. python3 -m cloudinit.cmd.main devel schema --docs \$mod;
done

PYTHONPATH=. python3 -m cloudinit.cmd.main devel schema --docs cc_landscape

Checklist:

• My code follows the process laid out in the documentation
• I have updated or added any unit tests accordingly
• I have updated or added any documentation accordingly

[TheRealFalcon]

Overall looks good. I left some comments inline. Additionally,

For landscape, we might want a way to indicate that the schema params are optional. Doesn't necessarily need to be inline in every parameter, but it's probably worth mentioning in the module description.

General comment: When setting distros or frequency in the meta schema, I don't think we need a separate variable definition if that's the only place it's used. E.g., use "distros": ["all"], and "frequency": PER_INSTANCE, instead of using new variables that don't get used anywhere else.

Rebase will be needed too.

[blackboxsw]

General comment: When setting distros or frequency in the meta schema, I don't think we need a separate variable definition if that's the only place it's used. E.g., use "distros": ["all"], and "frequency": PER_INSTANCE, instead of using new variables that don't get used anywhere else.

Turns out we do need them (see CI failures :)) because cloudinit.stages and cloudinit.config.fixup_module looks for module.frequency and module.distros attributes directly, which I think we need to fix to instead look for module.meta[]. I've added a separate jira card #888 for this. We can drop the module.frequency attribute from our schema definitions if the frequency is PER_INSTANCE as fixup_module will properly set the default when "absent" to PER_INSTANCE anyway.

[TheRealFalcon]

Ooph, that's bad. We should add a test (not part of this PR) that we're not getting that warning anywhere. I may have changed that in previous modules such that modules are now running per-instance rather than what they're being declared to run as.