azure-role-selector

Azure Role Selector

Recommend the most appropriate Azure RBAC roles following the principle of least privilege. Find minimal built-in roles or define custom roles when needed.

Adapted from github/awesome-copilot azure-role-selector skill.

When to Use

• When deploying resources that need RBAC assignments
• When configuring managed identity access between resources
• When setting up service principals for CI/CD pipelines
• During security analysis to verify correct role assignments
• When user asks "what role do I need for X?"

Procedure

1. Understand Required Permissions

Ask the user what actions they need to perform:

What permissions do you need? Examples:
- "Read and write blobs in a storage account"
- "Deploy code to a Function App"
- "Read secrets from Key Vault"
- "Manage SQL databases"
- "Full access to a resource group"

2. Search for Built-In Roles

Use Azure MCP documentation tools to find matching built-in roles:

# List relevant built-in roles
az role definition list \
  --query "[?contains(roleName, '{keyword}')].{Name:roleName, Description:description, Id:name}" \
  --output table

# Get detailed permissions for a role
az role definition list \
  --name "{role-name}" \
  --output json

Cross-reference with Microsoft Docs for the latest role definitions.

3. Recommend Least-Privilege Role

Present the recommended role(s) in order of least privilege:

## Role Recommendation

**Desired:** Read and write blobs in storage account starnwkdhk

### Recommended Role (Least Privilege)
| Property | Value |
|----------|-------|
| **Role** | Storage Blob Data Contributor |
| **ID** | ba92f5b4-2d11-453d-a403-e96b0029c9fe |
| **Scope** | Storage Account level |
| **Permissions** | Read, write, delete blobs and containers |

### Alternatives (More Permissive)
| Role | Extra Permissions | Use When |
|------|-------------------|----------|
| Storage Account Contributor | Full account management | Need to manage account settings too |
| Contributor | Full resource management | Need broad access (not recommended) |

### ⚠️ Avoid These (Over-Privileged)
- **Owner** — Grants RBAC management, not needed for data access
- **Contributor** at subscription level — Too broad for storage-only needs

4. Generate Assignment Commands

Provide ready-to-use commands:

Azure CLI:

# Assign role to managed identity
az role assignment create \
  --assignee {principal-id} \
  --role "Storage Blob Data Contributor" \
  --scope /subscriptions/{sub-id}/resourceGroups/{rg}/providers/Microsoft.Storage/storageAccounts/{name}

# Assign role to service principal
az role assignment create \
  --assignee {app-id} \
  --role "Storage Blob Data Contributor" \
  --scope {resource-id}

ARM Template (for inclusion in deployment):

{
  "type": "Microsoft.Authorization/roleAssignments",
  "apiVersion": "2022-04-01",
  "name": "[guid(resourceId('Microsoft.Storage/storageAccounts', '{name}'), '{principal-id}', 'ba92f5b4-2d11-453d-a403-e96b0029c9fe')]",
  "scope": "[resourceId('Microsoft.Storage/storageAccounts', '{name}')]",
  "properties": {
    "roleDefinitionId": "[subscriptionResourceId('Microsoft.Authorization/roleDefinitions', 'ba92f5b4-2d11-453d-a403-e96b0029c9fe')]",
    "principalId": "{principal-id}",
    "principalType": "ServicePrincipal"
  }
}

5. Custom Role (If No Built-In Matches)

If no built-in role matches the exact permissions needed:

# Create custom role definition
az role definition create --role-definition '{
  "Name": "Custom Storage Reader Writer",
  "Description": "Can read and write blobs but not delete",
  "Actions": [
    "Microsoft.Storage/storageAccounts/blobServices/containers/read",
    "Microsoft.Storage/storageAccounts/blobServices/containers/blobs/read",
    "Microsoft.Storage/storageAccounts/blobServices/containers/blobs/write"
  ],
  "NotActions": [],
  "DataActions": [
    "Microsoft.Storage/storageAccounts/blobServices/containers/blobs/read",
    "Microsoft.Storage/storageAccounts/blobServices/containers/blobs/write"
  ],
  "NotDataActions": [],
  "AssignableScopes": ["/subscriptions/{sub-id}"]
}'

Common Role Mappings

Integration with Git-Ape

When the template generator creates resources with managed identities, invoke this skill to:

1. Identify what roles the managed identity needs
2. Add role assignment resources to the ARM template
3. Follow least-privilege principle automatically