Azure Bicep: Infrastructure as Code Simplified

Azure Bicep is a domain-specific language for deploying Azure resources. Cleaner syntax than ARM templates, same deployment engine underneath.

Why Bicep?

ARM JSON	Bicep
Verbose	Concise
Complex syntax	Natural syntax
Hard to read	Easy to read
Reference functions	Simple references

Basic Syntax

// main.bicep
param location string = resourceGroup().location
param storageAccountName string

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-02-01' = {
  name: storageAccountName
  location: location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
  properties: {
    accessTier: 'Hot'
  }
}

output storageAccountId string = storageAccount.id
output primaryEndpoint string = storageAccount.properties.primaryEndpoints.blob

Deploy Bicep

# Deploy directly
az deployment group create \
    --resource-group myRG \
    --template-file main.bicep \
    --parameters storageAccountName=mystorage123

# Compile to ARM (optional)
az bicep build --file main.bicep

Variables and Expressions

var baseName = 'myapp'
var uniqueSuffix = uniqueString(resourceGroup().id)
var storageAccountName = '${baseName}${uniqueSuffix}'

// String interpolation
var connectionString = 'DefaultEndpointsProtocol=https;AccountName=${storageAccount.name};AccountKey=${storageAccount.listKeys().keys[0].value}'

Parameters with Decorators

@description('The environment name')
@allowed([
  'dev'
  'test'
  'prod'
])
param environment string

@minLength(3)
@maxLength(24)
param storageAccountName string

@secure()
param adminPassword string

@minValue(1)
@maxValue(10)
param instanceCount int = 2

Conditional Deployment

param deployStorage bool = true

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-02-01' = if (deployStorage) {
  name: storageAccountName
  location: location
  // ...
}

Loops

param storageAccounts array = [
  'storage1'
  'storage2'
  'storage3'
]

resource accounts 'Microsoft.Storage/storageAccounts@2021-02-01' = [for name in storageAccounts: {
  name: name
  location: location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}]

// Loop with index
resource indexedAccounts 'Microsoft.Storage/storageAccounts@2021-02-01' = [for (name, i) in storageAccounts: {
  name: '${name}${i}'
  // ...
}]

Modules

// modules/storage.bicep
param name string
param location string

resource storage 'Microsoft.Storage/storageAccounts@2021-02-01' = {
  name: name
  location: location
  sku: { name: 'Standard_LRS' }
  kind: 'StorageV2'
}

output id string = storage.id

// main.bicep
module storageModule 'modules/storage.bicep' = {
  name: 'storageDeployment'
  params: {
    name: 'mystorage'
    location: location
  }
}

output storageId string = storageModule.outputs.id

Existing Resources

// Reference existing resource
resource existingVnet 'Microsoft.Network/virtualNetworks@2021-02-01' existing = {
  name: 'my-existing-vnet'
}

resource subnet 'Microsoft.Network/virtualNetworks/subnets@2021-02-01' = {
  parent: existingVnet
  name: 'new-subnet'
  properties: {
    addressPrefix: '10.0.1.0/24'
  }
}

Complete Example

// Deploy web app with SQL
param appName string
param sqlAdminPassword string

resource sqlServer 'Microsoft.Sql/servers@2021-02-01-preview' = {
  name: '${appName}-sql'
  location: location
  properties: {
    administratorLogin: 'sqladmin'
    administratorLoginPassword: sqlAdminPassword
  }
}

resource sqlDb 'Microsoft.Sql/servers/databases@2021-02-01-preview' = {
  parent: sqlServer
  name: '${appName}-db'
  location: location
  sku: {
    name: 'Basic'
  }
}

resource appServicePlan 'Microsoft.Web/serverfarms@2021-01-01' = {
  name: '${appName}-plan'
  location: location
  sku: {
    name: 'S1'
  }
}

resource webApp 'Microsoft.Web/sites@2021-01-01' = {
  name: appName
  location: location
  properties: {
    serverFarmId: appServicePlan.id
  }
}

Bicep: ARM templates you can actually read.