Azure Deployment Preflight Validation

This skill validates Bicep deployments before execution, supporting both Azure CLI (az) and Azure Developer CLI (azd) workflows.

When to Use This Skill Before deploying infrastructure to Azure When preparing or reviewing Bicep files To preview what changes a deployment will make To verify permissions are sufficient for deployment Before running azd up, azd provision, or az deployment commands Validation Process

Follow these steps in order. Continue to the next step even if a previous step fails—capture all issues in the final report.

Step 1: Detect Project Type

Determine the deployment workflow by checking for project indicators:

Check for azd project: Look for azure.yaml in the project root

If found → Use azd workflow If not found → Use az CLI workflow

Locate Bicep files: Find all .bicep files to validate

For azd projects: Check infra/ directory first, then project root For standalone: Use the file specified by the user or search common locations (infra/, deploy/, project root)

Auto-detect parameter files: For each Bicep file, look for matching parameter files:

.bicepparam (Bicep parameters - preferred) .parameters.json (JSON parameters) parameters.json or parameters/.json in same directory Step 2: Validate Bicep Syntax

Run Bicep CLI to check template syntax before attempting deployment validation:

bicep build --stdout

What to capture:

Syntax errors with line/column numbers Warning messages Build success/failure status

If Bicep CLI is not installed:

Note the issue in the report Continue to Step 3 (Azure will validate syntax during what-if) Step 3: Run Preflight Validation

Choose the appropriate validation based on project type detected in Step 1.

For azd Projects (azure.yaml exists)

Use azd provision --preview to validate the deployment:

azd provision --preview

If an environment is specified or multiple environments exist:

azd provision --preview --environment

For Standalone Bicep (no azure.yaml)

Determine the deployment scope from the Bicep file's targetScope declaration:

Target Scope Command resourceGroup (default) az deployment group what-if subscription az deployment sub what-if managementGroup az deployment mg what-if tenant az deployment tenant what-if

Run with Provider validation level first:

Resource Group scope (most common)

az deployment group what-if \ --resource-group \ --template-file \ --parameters \ --validation-level Provider

Subscription scope

az deployment sub what-if \ --location \ --template-file \ --parameters \ --validation-level Provider

Management Group scope

az deployment mg what-if \ --location \ --management-group-id \ --template-file \ --parameters \ --validation-level Provider

Tenant scope

az deployment tenant what-if \ --location \ --template-file \ --parameters \ --validation-level Provider

Fallback Strategy:

If --validation-level Provider fails with permission errors (RBAC), retry with ProviderNoRbac:

az deployment group what-if \ --resource-group \ --template-file \ --validation-level ProviderNoRbac

Note the fallback in the report—the user may lack full deployment permissions.

Step 4: Capture What-If Results

Parse the what-if output to categorize resource changes:

Change Type Symbol Meaning Create + New resource will be created Delete - Resource will be deleted Modify ~ Resource properties will change NoChange = Resource unchanged Ignore * Resource not analyzed (limits reached) Deploy ! Resource will be deployed (changes unknown)

For modified resources, capture the specific property changes.

Step 5: Generate Report

Create a Markdown report file in the project root named:

preflight-report.md

Use the template structure from references/REPORT-TEMPLATE.md.

Report sections:

Summary - Overall status, timestamp, files validated, target scope Tools Executed - Commands run, versions, validation levels used Issues - All errors and warnings with severity and remediation What-If Results - Resources to create/modify/delete/unchanged Recommendations - Actionable next steps Required Information

Before running validation, gather:

Information Required For How to Obtain Resource Group az deployment group Ask user or check existing .azure/ config Subscription All deployments az account show or ask user Location Sub/MG/Tenant scope Ask user or use default from config Environment azd projects azd env list or ask user

If required information is missing, prompt the user before proceeding.

Error Handling

See references/ERROR-HANDLING.md for detailed error handling guidance.

Key principle: Continue validation even when errors occur. Capture all issues in the final report.

Error Type Action Not logged in Note in report, suggest az login or azd auth login Permission denied Fall back to ProviderNoRbac, note in report Bicep syntax error Include all errors, continue to other files Tool not installed Note in report, skip that validation step Resource group not found Note in report, suggest creating it Tool Requirements

This skill uses the following tools:

Azure CLI (az) - Version 2.76.0+ recommended for --validation-level Azure Developer CLI (azd) - For projects with azure.yaml Bicep CLI (bicep) - For syntax validation Azure MCP Tools - For documentation lookups and best practices

Check tool availability before starting:

az --version azd version bicep --version

Example Workflow User: "Validate my Bicep deployment before I run it" Agent detects azure.yaml → azd project Agent finds infra/main.bicep and infra/main.bicepparam Agent runs bicep build infra/main.bicep --stdout Agent runs azd provision --preview Agent generates preflight-report.md in project root Agent summarizes findings to user Reference Documentation Validation Commands Reference Report Template Error Handling Guide