docs: Add charm architecture documentation

[cbartz]

Applicable spec:

Overview

Add charm architecture documentation

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

[cbartz]

Hi @yanksyoon , can you please do a technical (not stylistic) review? Thanks.

[yanksyoon]

Thanks for the documentation, LGTM!
Im also wondering how detailed the scope of the documentation should be (e.g. should we describe why its a machine charm running docker containers, what type of fingerprints are generated...etc), the current scope looks fine to me though.

[cbartz]

Thanks for the documentation, LGTM! Im also wondering how detailed the scope of the documentation should be (e.g. should we describe why its a machine charm running docker containers, what type of fingerprints are generated...etc), the current scope looks fine to me though.

@yanksyoon I think specific reasons why it is a machine charm could be included. Can you tell us the reasoning behind design decisions in the past? I assume a k8s charm would be more difficult to implement in terms of ingress via ssh ?

[erinecon]

Thanks for adding architecture documentation! It looks great to me 🎉

[erinecon]

A few remaining details and then we should be good to go :)

[erinecon]

Thanks for adding the architecture documentation and diagram!

[yanksyoon]

LGTM, thank you!