Bicep：最新の Azure IaC

Bicep とは何か、なぜ使用するのか

Bicep と ARM JSON の構文比較

// Bicep: deploy a storage account
param storageAccountName string
param location string = resourceGroup().location
param sku string = 'Standard_LRS'

resource storageAccount 'Microsoft.Storage/storageAccounts@2023-01-01' = {
  name: storageAccountName
  location: location
  sku: {
    name: sku
  }
  kind: 'StorageV2'
  properties: {
    supportsHttpsTrafficOnly: true
    minimumTlsVersion: 'TLS1_2'
  }
}

Bicep のパラメーターとデコレーター

@description('Globally unique name for the storage account')
@minLength(3)
@maxLength(24)
param storageAccountName string

@allowed(['Standard_LRS', 'Standard_GRS', 'Premium_LRS'])
param sku string = 'Standard_LRS'

@secure()
param adminPassword string

Bicep の変数と式

param environment string = 'dev'
param baseName string = 'myapp'

var uniqueSuffix = uniqueString(resourceGroup().id)
var storageAccountName = '${baseName}${environment}${uniqueSuffix}'
var isProd = environment == 'prod'
var skuName = isProd ? 'Standard_GRS' : 'Standard_LRS'

リソース宣言とシンボリック名

resource vnet 'Microsoft.Network/virtualNetworks@2023-05-01' = {
  name: 'myVNet'
  location: location
  properties: {
    addressSpace: { addressPrefixes: ['10.0.0.0/16'] }
  }
}

// Implicit dependency via symbolic name reference
resource subnet 'Microsoft.Network/virtualNetworks/subnets@2023-05-01' = {
  parent: vnet  // Bicep knows to create vnet first
  name: 'mySubnet'
  properties: {
    addressPrefix: '10.0.1.0/24'
  }
}

Bicep の出力

output storageAccountName string = storageAccount.name
output blobEndpoint string = storageAccount.properties.primaryEndpoints.blob
output storageAccountId string = storageAccount.id

Bicep モジュール

// main.bicep — consuming a storage module
module storage './modules/storage.bicep' = {
  name: 'storageDeploy'
  params: {
    storageAccountName: 'myuniquestorage'
    location: location
    sku: 'Standard_LRS'
  }
}

// Reference module output in parent template
output blobUri string = storage.outputs.blobEndpoint

ARM テンプレートから Bicep への変換

# Install the Bicep CLI (or use it via Azure CLI)
az bicep install
az bicep upgrade

# Decompile existing ARM JSON to Bicep
az bicep decompile --file azuredeploy.json
# Produces azuredeploy.bicep in the same directory

# Compile Bicep to ARM JSON (for inspection)
az bicep build --file main.bicep

Azure CLI を使用した Bicep のデプロイ

# Deploy a Bicep file directly
az deployment group create \
  --resource-group MyRG \
  --template-file main.bicep \
  --parameters storageAccountName=myprodstore environment=prod

# What-if preview with Bicep
az deployment group what-if \
  --resource-group MyRG \
  --template-file main.bicep \
  --parameters storageAccountName=myprodstore environment=prod

Bicep のループと条件

// Loop: create multiple storage accounts
param storageNames array = ['alpha', 'beta', 'gamma']

resource stores 'Microsoft.Storage/storageAccounts@2023-01-01' = [for name in storageNames: {
  name: '${name}${uniqueString(resourceGroup().id)}'
  location: location
  sku: { name: 'Standard_LRS' }
  kind: 'StorageV2'
}]

// Condition: only deploy in prod
param deployKeyVault bool = false

resource kv 'Microsoft.KeyVault/vaults@2023-07-01' = if (deployKeyVault) {
  name: 'myKeyVault'
  location: location
  properties: { sku: { family: 'A', name: 'standard' }, tenantId: subscription().tenantId, accessPolicies: [] }
}

Bicep のツールと lint

# Run the Bicep linter
az bicep lint --file main.bicep

# Format a Bicep file
az bicep format --file main.bicep

# Generate resource type documentation
az bicep generate-params --file main.bicep --output-format json

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