×
Lance Anderson

Setting Azure Web App Slot Auto Swap Using ARM Templates and Terraform

Written by Ken Dale
3
This post is days old.

We’re in the process of scaffolding out our Microsoft Azure environments using Terraform. We’re looking at deploying consistently from master going forward, but our new infrastructure design requires explicit swapping of staging slots to production. We want this to happen automatically though in our development environment, ensuring we’re always using the latest code as we try things out in the cloud.

Many items in Terraform are supported in a first-class manner. However, sometimes you find an item not currently supported. In the case of Azure, we can specify absent Terraform provider functionality we need using ARM templates. It’s a bit more verbose to setup than a simple built-in property, but it works.

Here’s the code:

Terraform

Assuming azurerm_app_service.app_service and azurerm_app_service_slot.app_service_slot are available (update this template as needed):

resource "azurerm_template_deployment" "app_service_auto_swap" {
  name                = "my-app-service-auto-swap" 
  resource_group_name = "YOUR_RESOURCE_GROUP_NAME"
  deployment_mode     = "Incremental"

  template_body = "${file("./path/to/app-service-slot-auto-swap.json")}"

  parameters {
    "existingWebAppLocation" = "eastus"
    "webAppName"             = "${azurerm_app_service.app_service.name}"
    "slotName"               = "staging"
    "autoSwapSlotName"       = "production"
  }

  depends_on = [
    "azurerm_app_service.app_service",
    "azurerm_app_service_slot.app_service_slot"
  ]
}

ARM Template

app-service-slot-auto-swap.json

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "existingWebAppLocation": {
      "type": "string",
      "metadata": {
        "description": "App location"
      }
    },
    "webAppName": {
      "type": "string",
      "metadata": {
        "description": "Example: app-name"
      }
    },
    "slotName": {
      "type": "string",
      "metadata": {
        "description": "Example: staging"
      }
    },
    "autoSwapSlotName": {
      "type": "string",
      "metadata": {
        "description": "Example: production"
      }
    }
  },
  "resources": [
    {
      "type": "Microsoft.Web/sites/slots",
      "name": "[concat(parameters('webAppName'), '/', parameters('slotName'))]",
      "apiVersion": "2015-08-01",
      "location": "[parameters('existingWebAppLocation')]",
      "properties": {
        "siteConfig": {
          "autoSwapSlotName": "[parameters('autoSwapSlotName')]"
        }
      }
    }
  ]
}
Ken Dale
Ken Dale
Senior Application Developer
Azure
Terraform
Suggested reading

Running an AppVeyor Build After Creating an Azure Web App Using Terraform

Terraform
We’re in the process of scaffolding out our Microsoft Azure environments usin...
Read now

Export CSV Table of All Azure Web Apps Configuration in Subscription

Azure
At Ritter Insurance Marketing we utilize Azure Web Apps for hosting many of o...
Read now

Secure Global Stuntman Users With Windows Azure Blob Storage

Azure
Stuntman is an open source library we developed at RIMdev to make testing use...
Read now

Jekyll and IIS Web Configuration in Windows Azure

Azure
In a previous post, “Deploying Jekyll on Windows Azure”, I detailed how to ge...
Read now

Copying App Settings and Connection Strings Between Azure Web Apps

Azure
At Ritter Insurance Marketing we utilize Azure Web Apps for hosting many of o...
Read now

Comments

Stay fresh! The brighter green, the fresher the article!