Creating an Azure WebApp through ARM and Node.js

August 4th, 2017

I recently posted an article on how to create an Azure WebApp on AppService with an associated Application Insights resource using Azure Resource Manager (ARM) templates.

I’ve been playing the past couple of days with the Azure SDK for Node.js, and thought I’d write how to accomplish the same thing through code. Let’s recap what we want to create from our previous article:

  • Create a new resource group
  • Create an Application Insights resource
  • Create a new App Service Plan
  • Create a new WebApp on this ASP
  • Configure the AppInsights InstrumentationKey as an appSettings
  • Deploy the Application Insights site extension

Our first step using the SDK is to import the ms-rest-azure package and login to our Azure account using an interactive login:

const MsRest = require('ms-rest-azure');
// ...
login() {
    return MsRest.interactiveLogin({ domain: this.tenantId });
}

This will give us a credentials object we can use later for the rest of the calls. Once this is successful, we can use the azure-arm-resource package to create the resource group. All we need to specify is the name of the new resource group, and the Azure region we want to use:

const ResourceManagement = require('azure-arm-resource');
// ...
createResourceGroup(resourceInfo) {
    let group =  {
        location: this.location
    };
    let rgmanagement = new ResourceManagement.ResourceManagementClient(resourceInfo.credentials, this.subscriptionId);
    return rgmanagement.resourceGroups.createOrUpdate(this.resourceGroupName, group)
}

The next step is to create a new Application Insights resource in our resource group. Like in our ARM template sample, we want to provision a tag that will later link it to the WebApp once we create it. The azure-arm-insights package, unfortunately, does not support managing components resources, so we need to use the generic azure-arm-resources package to create a new resource of type `microsoft.insights/components’:

createAppInsights(resourceInfo) {
    let envelope = {
        location: this.location,
        properties: {},
        tags: {
        }
    };
    let webAppId = `${resourceInfo.resourceGroup.id}/providers/Microsoft.Web/sites/${this.webAppName}`
    envelope.tags[`hidden-link:${webAppId}`] = 'Resource';

    let management = new ResourceManagement.ResourceManagementClient(resourceInfo.credentials, this.subscriptionId);
    return management.resources.createOrUpdate(
        this.resourceGroupName, // resource group
        'microsoft.insights',   // provider namespace
        '',                     // parent resource
        'components',           // resource type
        this.appInsightsName,   // resource name
        '2014-04-01',           // api version
        envelope);
}

We can now create the App Service Plan and the WebApp using the azure-arm-website package. Creating the ASP is relatively straightforward; we just need the name, location, tier and capacity. Creating the application takes a little bit more work, and for this we will need:

  • The ID of the App Service Plan created
  • The object returned by our previous step to get the InstrumentationKey of the Application Insights resource:
const WebAppManagementClient = require('azure-arm-website');
// ...
createHostingPlan(resourceInfo) {
    var info = {
        location: this.location,
        sku: {
            name: this.webPlanTier,
            capacity: this.webPlanCapacity
        }
    };
    let wam = new WebAppManagementClient(resourceInfo.credentials, this.subscriptionId);
    return wam.appServicePlans.createOrUpdate(this.resourceGroupName, this.webPlanName, info);
}

createWebApp(resourceInfo) {
    var envelope = {
        name: this.webAppname,
        location: this.location,
        kind: 'web',
        serverFarmId: resourceInfo.webHostingPlan.id,
        properties: {
        },
        siteConfig: {
            appSettings: [
                {
                    name: 'APPINSIGHTS_INSTRUMENTATIONKEY', 
                    value: resourceInfo.appInsights.properties.InstrumentationKey
                }
            ]
        }
    };
    let wam = new WebAppManagementClient(resourceInfo.credentials, this.subscriptionId);
    return wam.webApps.createOrUpdate(this.resourceGroupName, this.webAppName, envelope);
}

Our final step is to deploy the Application Insights site extension onto our new WebApp. There doesn’t seem to be support in the azure-arm-website package to create site extensions, so again we will use the azure-arm-resource package to create it as a generic resource. This takes a little bit more work as we need to specify the WebApp as the ‘parent’ resource:

addAppInsightsExtension(resourceInfo) {
    var envelope = {
        location: this.location,
        properties: {}
    };
    let management = new ResourceManagement.ResourceManagementClient(resourceInfo.credentials, this.subscriptionId);
    return management.resources.createOrUpdate(
        this.resourceGroupName,                         // resource group
        'Microsoft.Web/sites',                          // provider namespace
        this.webAppName,                                // parent resource
        'siteextensions',                               // resource type
        'Microsoft.ApplicationInsights.AzureWebSites',  // resource name
        '2015-08-01',                                   // api version
        envelope);
}

Conclusion

Here we saw how we can leverage the Azure SDK for Node to automate the creation of Azure resources. In this case, we covered a common scenario of deploying a Web application on AppService with Application Insights.

This was also a good way to get a little bit more into Node and JavaScript, so it’s probably a bit clunky. Any good feedback or suggestions would sure be welcome!

You can find the complete code here.

Tomas Restrepo

Software developer located in Colombia.