docs: add a tip to add extra settings through configmaps or secrets and improve an example for that

[kurokobo]

SUMMARY

The page "Custom volume and volume mount options" contains an example of mounting custom.py under /etc/tower/conf.d/ that contains extra settings for AWX.

This is very handy way if users' exta_settings is too big, but there is less information about this way. I think the page for exta_settings should contain this alternative handy way.

This PR changes:

• Add a tip to provide alternative way to add extra settings by mounting configmaps or secrets of *.py files.
• Add web_extra_volume_mounts in the example in custom-volume-and-volume-mount-options.md to ensure custom.py is mounted on both task and web pods.
• Fix minor issues
  • Correct indentation for the code blocks in custom-volume-and-volume-mount-options.md.
  • Correct warning block in custom-volume-and-volume-mount-options.md.

ISSUE TYPE

• Bug, Docs Fix or other nominal change

ADDITIONAL INFORMATION

The main setting file /etc/tower/settings.py is also mounted on the migration job pods and the metrics utility job pods, and currently there is no way to add custom volumes to migration job pod and metrics utility job pods.

Mounting custom.py may cause inconsistencies between the setting files in the task/web pods and migration/metrics utility pods, but I do not expect that custom.py will provide any settings that would affect migrations or metrics utilities. Please let me know if I am wrong (in which case I should rather remove the custom.py from this examples).

[kurokobo]

Extra settings:

Custom volume and volume mount options:

[rooftopcellist]

@kurokobo Thank you for contributing these docs!

As an aside, it would be nice to make this easier for users. Maybe we could add a settings_file_configmap parameter that would automatically mount the contents of the configmap specified into the respective containers.

Generally, we try not to add unnecessary new parameters, but this is a common enough use case and would say users the trouble of double quotes issues on values for the existing extra_settings param implementation.

What do you think about that idea?

[kurokobo]

@rooftopcellist
Hi, thanks for reviewing and merging.

As an aside, it would be nice to make this easier for users. Maybe we could add a settings_file_configmap parameter that would automatically mount the contents of the configmap specified into the respective containers.

Yes, this is exactly one of the things I was going to draft as an RFE. I already made quick investigation and it seems to that perhaps we can implement almost same things on Galaxy Operator and EDA Server Operator as well.
On both galaxy_ng and eda-server, there are no predefined configuration directory (like /etc/tower/conf.d for AWX), but both of them already have django-split-settings that can include multiple files into main settings file. So I didn't test at all, but I think,

• For Galaxy Operator. we may be able to add include to load custom settings files into settings.py that generated by Galaxy Operator
• For EDA Server Operator, we may be able to define EDA_SETTINGS_FILE with a python file that generated by EDA Server Operator that contains include

For now, let me make an RFE for AWX Operator.