azure-deployment-preflight

SKILL.md

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:

<filename>.bicepparam (Bicep parameters - preferred)

<filename>.parameters.json (JSON parameters)

parameters.json or parameters/<env>.json in same directory

Step 2: Validate Bicep Syntax

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

bicep build <bicep-file> --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 <env-name>

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 <rg-name> \
  --template-file <bicep-file> \
  --parameters <param-file> \
  --validation-level Provider

# Subscription scope
az deployment sub what-if \
  --location <location> \
  --template-file <bicep-file> \
  --parameters <param-file> \
  --validation-level Provider

# Management Group scope
az deployment mg what-if \
  --location <location> \
  --management-group-id <mg-id> \
  --template-file <bicep-file> \
  --parameters <param-file> \
  --validation-level Provider

# Tenant scope
az deployment tenant what-if \
  --location <location> \
  --template-file <bicep-file> \
  --parameters <param-file> \
  --validation-level Provider

Fallback Strategy:

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

az deployment group what-if \
  --resource-group <rg-name> \
  --template-file <bicep-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