Nutshell Series

Azure Bicep Cheat Sheet (2025)

Manjunath

What is Azure Bicep?

Bicep is a Domain Specific Language (DSL) for Azure Resource Manager. It simplifies ARM JSON templates into readable and modular code for Infrastructure as Code on Azure.

Basic Structure

@description('Storage account name')
param storageAccountName string
param storageSku string = 'Standard_LRS'

var location = resourceGroup().location

resource storageAccount 'Microsoft.Storage/storageAccounts@2023-01-01' = {
  name: storageAccountName
  location: location
  sku: {
    name: storageSku
  }
  kind: 'StorageV2'
}

output storageEndpoint string = storageAccount.properties.primaryEndpoints.blob

Parameters

@description('Admin username')
param adminUser string = 'azureuser'

@secure()
param adminPassword string

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

Variables

var prefix = 'demo'
var uniqueName = '${prefix}${uniqueString(resourceGroup().id)}'
var subnetNames = ['web', 'app', 'db']

Expressions & Interpolation

var fullName = '${prefix}-${environment}-${location}'
var uniqueName = toLower(uniqueString(resourceGroup().id, 'key'))

Resource Declaration

resource myVnet 'Microsoft.Network/virtualNetworks@2023-01-01' = {
  name: 'vnet-${uniqueString(resourceGroup().id)}'
  location: location
  properties: {
    addressSpace: {
      addressPrefixes: ['10.0.0.0/16']
    }
  }
}

Resource Dependencies

Implicit dependency:

resource nic 'Microsoft.Network/networkInterfaces@2023-01-01' = {
  name: 'vmNic'
  properties: {
    ipConfigurations: [
      {
        name: 'ipconfig'
        properties: {
          subnet: { id: subnet.id }
        }
      }
    ]
  }
}

Explicit dependency:

dependsOn: [ nic, storageAccount ]

Loops

var subnets = [
  { name: 'web', prefix: '10.0.1.0/24' }
  { name: 'app', prefix: '10.0.2.0/24' }
]

resource vnet 'Microsoft.Network/virtualNetworks@2023-01-01' = {
  name: 'myVnet'
  properties: {
    addressSpace: { addressPrefixes: ['10.0.0.0/16'] }
    subnets: [for subnet in subnets: {
      name: subnet.name
      properties: { addressPrefix: subnet.prefix }
    }]
  }
}

Conditional Deployment

param enableDiagnostics bool = true

resource diag 'Microsoft.Insights/diagnosticSettings@2021-05-01-preview' = if (enableDiagnostics) {
  name: 'diagSetting'
  properties: {
    ...
  }
}

Modules

Main file:

module storage './storage.bicep' = {
  name: 'storageModule'
  params: {
    storageAccountName: 'mystorage'
    location: location
  }
}

storage.bicep:

param storageAccountName string
param location string

resource storage 'Microsoft.Storage/storageAccounts@2023-01-01' = {
  name: storageAccountName
  location: location
  sku: { name: 'Standard_LRS' }
  kind: 'StorageV2'
}

output storageId string = storage.id

Outputs

output storageId string = storage.id
output connectionString string = 'DefaultEndpointsProtocol=https;AccountName=${storage.name}'

Common Functions

  • resourceGroup() – Current resource group
  • uniqueString() – Deterministic unique ID
  • concat() – Join strings
  • length() – Array or string length
  • contains() – Checks if array contains value
  • if() – Inline condition
  • json() – Parse JSON

Azure CLI Commands

az deployment group create \
  --resource-group myRG \
  --template-file main.bicep \
  --parameters storageSku=Standard_LRS

az deployment group validate \
  --resource-group myRG \
  --template-file main.bicep

az deployment group what-if \
  --resource-group myRG \
  --template-file main.bicep

Scopes

targetScope = 'subscription'

resource rg 'Microsoft.Resources/resourceGroups@2023-01-01' = {
  name: 'myResourceGroup'
  location: 'eastus'
}

Best Practices

  • Use modules for reusable components
  • Validate parameters using @allowed, @minLength
  • Tag all resources consistently
  • Use loops instead of duplicate code
  • Preview changes using what-if
  • Avoid exposing secrets in outputs
  • Keep Bicep files under version control

Helpful CLI Commands

az bicep install
az bicep upgrade
az bicep build --file main.bicep
az bicep decompile --file template.json

Common Resource Types

  • Storage Account – Microsoft.Storage/storageAccounts@2023-01-01
  • Virtual Network – Microsoft.Network/virtualNetworks@2023-01-01
  • Virtual Machine – Microsoft.Compute/virtualMachines@2023-01-01
  • App Service – Microsoft.Web/sites@2023-01-01
  • Key Vault – Microsoft.KeyVault/vaults@2023-01-01

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