Add diagram of installer-based provisioning with PXE boot

[Lennonka]

What changes are you introducing?

Adding a sequence diagram of installer-based provisioning with PXE boot. Using PlantUML to build the diagram.

Why are you introducing these changes? (Explanation, links to references, issues, etc.)

Preparation for improvements of Provisioning hosts. The diagram will be used later to explain the workflow of the provisioning method.

Anything else to add? (Considerations, potential downsides, alternative solutions you have explored, etc.)

• Some files (.iuml, .pstyle) are expected to be reused in mutiple diagrams.
• Continuation of https://github.com/theforeman/foreman-documentation/pull/3069

Checklists

• [x] I am okay with my commits getting squashed when you merge this PR.
• [x] I am familiar with the contributing guidelines.

Please cherry-pick my commits into: N/A

[github-actions[bot]]

The PR preview for 4254ddcd8a97bb58846f9d88a5a241c9088e7be9 is available at theforeman-foreman-documentation-preview-pr-3304.surge.sh

The following output files are affected by this PR:

show diff

show diff as HTML

[Lennonka]

Comments for the "Create host in Foreman" part.

One question: Right now, the happy path workflow is described. Do we want to also show paths when, for example, DHCP reservations fail? IMO, it would make the diagram crazy big, but it's something to think about.

The diagram is already crazy big. I think we should go with the happy path only. We're not writing a design specification, we're trying to familiarize the user with the basic workflow.

[Lennonka]

I have enabled the display of Puppet parts because in upstream that's welcome. Also cleaned up the style of the diagram and rebased the PR.

FYI I have kept 3 notes over Host that mark the status of the host at the given times. I think that it's the appropriate use of the notes.

[Lennonka]

@asteflova Can you please review the diagram for style and give it a final ack if okay? I tried to incorporate Avital's comments from #3309 and I have provided a preview inside the docs just to check that the text in the diagram will be readable once included. The module that provides the preview will not be merged at this time.

[asteflova]

@asteflova Can you please review the diagram for style and give it a final ack if okay?

Hi @Lennonka, to be honest, I wasn't going to review. I can't think of anything that I could review in terms of style in a diagram that is not being used in the docs. I believe feedback from Avital is more than enough.

[Lennonka]

@asteflova Does it mean that I can set the style review done label?

[asteflova]

Ah, now I see that Avital reviewed another PR, not this one.

@asteflova Does it mean that I can set the style review done label?

I was under the impression that your goal was to create the diagrams but not add them to any guides just yet. Has that changed? I can now see it included in the guide builds, including the d/s Satellite build.

[Lennonka]

@asteflova Avital has asked me to provide a temporary preview so that we can check that the text in the diagram is readable. This will not be included in the merge.

[asteflova]

Thanks for explaining! In that case, I'd say there is nothing to review in terms of 'style review'.