[Feature Request]: Allow skipping the 'Agent Install' tasks when self-hosted agents are in use and have limited Internet connectivity

[ahmadabdalla]

Description

Problem space

Currently the CARML CI has a task in the pipeline templates that performs agent's configuration for pre-requisites (i.e. PowerShell Azure Modules), which requires the agent to have access to PS Gallery.

In isolated environments, it can be difficult to allow agents to have access to the PSGallery, and the pre-requisites can be fetched from a different source.

Feature request

Allow skipping the tasks related to the agent setup as a switch in the settings.yml

Example:

• Create a switch called installAgentPreRequisites and set it to true as default.
• Create a condition on the tasks for agent install in all pipeline job templates to skip this stage condition: eq(variables['installAgentPreRequisites'], true)

Another option

We could also use this switch to have a value like validateOnly, installOnly, none to support a scenario where we'd want to validate that the pre-requisites are installed opposed to installing them

[AlexanderSehr]

Hey @ahmadabdalla good idea. I'd suggest to follow your proposal with a switch as opposed to the set of strings as also a 'validate only' would fail in an isolated environment.
However - the ensure users know what they're getting into, we should add some documentation of what is expected on the agents. For example, xzy powershell modules, Bicep, PowerShell Core 7.3.0 or newer, etc.