Bicep Coding Standards

Goal: Create consistent, secure Azure infrastructure

Naming Convention

Use resourceToken from uniqueString():

bicep

var token = toLower(uniqueString(subscription().id, environmentName, location))
name: '${abbrs.appContainerApps}web-${token}'  // ca-web-abc123

Exception: ACR requires alphanumeric only: cr${resourceToken}

Parameters

Always add @description() and use @allowed() for constrained values:

bicep

@description('Environment (dev, prod)')
param environmentName string

@description('Azure region')
@allowed(['eastus2', 'westus2'])
param location string = 'eastus2'

Outputs

Expose key identifiers for azd and other modules:

bicep

output containerAppName string = containerApp.name
output webEndpoint string = 'https://${containerApp.properties.configuration.ingress.fqdn}'
output identityPrincipalId string = containerApp.identity.principalId

Managed Identity

Always use system-assigned identity + output principalId:

bicep

identity: { type: 'SystemAssigned' }
output identityPrincipalId string = resource.identity.principalId

RBAC Assignments

Use guid() for names + specify principalType:

bicep

resource roleAssignment 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
  name: guid(resource.id, principalId, roleId)
  properties: {
    roleDefinitionId: subscriptionResourceId('Microsoft.Authorization/roleDefinitions', roleId)
    principalId: principalId
    principalType: 'ServicePrincipal'
  }
}

Container Apps

Key settings: System identity + scale-to-zero + HTTPS only:

bicep

resource containerApp 'Microsoft.App/containerApps@2023-05-01' = {
  identity: { type: 'SystemAssigned' }
  properties: {
    configuration: {
      ingress: {
        external: true
        targetPort: 8080
        allowInsecure: false
      }
    }
    template: {
      scale: { minReplicas: 0, maxReplicas: 3 }
    }
  }
}

Secrets Pattern

Use Container App secrets + listCredentials():

bicep

secrets: [{
  name: 'registry-password'
  value: containerRegistry.listCredentials().passwords[0].value
}]

Validation

powershell

az bicep build --file main.bicep
az deployment group what-if --template-file main.bicep

Project-Specific: Module Hierarchy

code

main.bicep (subscription scope)
├─ Resource group
├─ main-infrastructure.bicep (ACR + Container Apps Env + Log Analytics)
├─ main-app.bicep (Container App)
└─ RBAC (Cognitive Services User role)

Project-Specific: Container App Configuration

bicep

resource containerApp 'Microsoft.App/containerApps@2023-05-01' = {
  identity: { type: 'SystemAssigned' }
  properties: {
    managedEnvironmentId: containerAppsEnvironmentId
    configuration: {
      ingress: {
        external: true
        targetPort: 8080
        allowInsecure: false
      }
      secrets: [{
        name: 'registry-password'
        value: containerRegistry.listCredentials().passwords[0].value
      }]
    }
    template: {
      containers: [{
        name: 'web'
        image: containerImage
        env: [
          { name: 'ENTRA_SPA_CLIENT_ID', value: entraSpaClientId }
          { name: 'AI_AGENT_ENDPOINT', value: aiAgentEndpoint }
          { name: 'AI_AGENT_ID', value: aiAgentId }
        ]
        resources: { cpu: json('0.5'), memory: '1Gi' }
      }]
      scale: { minReplicas: 0, maxReplicas: 3 }
    }
  }
}

output fqdn string = containerApp.properties.configuration.ingress.fqdn
output identityPrincipalId string = containerApp.identity.principalId

Related Skills

•deploying-to-azure - Deployment commands and hook workflow
•writing-csharp-code - Backend configuration for Container Apps
•troubleshooting-authentication - RBAC and managed identity debugging