feat: Add support for reusing existing Log Analytics Workspace

[Abdul-Microsoft]

Purpose

• This pull request introduces support for reusing an existing Azure Log Analytics Workspace during deployment, instead of always provisioning a new one. It adds new documentation to guide users through the process and updates the infrastructure code to accept and use an existing workspace ID when provided. The changes also ensure that all relevant modules and resources use the specified workspace for monitoring and diagnostics.

Support for existing Log Analytics Workspace:

• Added a new parameter existingLogAnalyticsWorkspaceId to infra/main.bicep, infra/main.json, and parameter files, allowing users to specify the resource ID of an existing Log Analytics Workspace. All modules that require a Log Analytics Workspace now use this parameter if provided, falling back to provisioning a new workspace only if not set. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]

Documentation updates:

• Updated docs/CustomizingAzdParameters.md and docs/DeploymentGuide.md to describe the new environment variable AZURE_ENV_LOG_ANALYTICS_WORKSPACE_ID and how to use it. Added a collapsible section in the deployment guide to highlight reusing an existing workspace. [1] [2]
• Added a new guide docs/re-use-log-analytics.md with step-by-step instructions and screenshots to help users find the correct workspace ID and configure their environment.

Infrastructure logic improvements:

• Updated logic in Bicep and ARM templates to conditionally provision a new workspace only if an existing one is not specified, and to consistently pass the correct workspace resource ID to all dependent modules and diagnostic settings. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

Parameter and template consistency:

• Added the new parameter to all relevant parameter files to ensure consistent configuration across different deployment scenarios. [1] [2]

Minor template maintenance:

• Updated template hash and adjusted resource dependencies for ordering consistency in infra/main.json. [1] [2] [3]

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.

What to Check

Verify that the following are valid

• ...

Other Information