Using Parameter File With Bicep Templates

In the previous post we went through the process of deploying an Bicep template using parameter that where called directly from PowerShell.

This is ok when deploying resources that require only a few values to be set, but this can become difficult to manage when there are a lot of parameter like when deploying virtual machines or web apps.

A parameter file for Bicep is a json file that has the specific parameter names and values set.

I used this Microsoft document as a reference to create the parameter file.

https://docs.microsoft.com/en-us/azure/azure-resource-manager/bicep/parameter-files

Below is the Bicep file we create in the last post.

A parameter file for the storage Bicep template would look like the below.

Once we have the parameter file, we are ready to test the deployment. To test without actually deploying the resource add the whatif parameter.

New-AzResourceGroupDeployment -ResourceGroupName ResourceGroupName -TemplateFile .\BicepTemplate.bicep -TemplateParameterFile .\BicepParamter.json -WhatIf

Next we will create a template to deploy a virtual machine and it network interface. To create base template in visual studio code type

res-nic to populate the network interface:

Use res-vm-windows to populate the virtual machine.

I will be creating parameters for each part that requires customization and anything that doesn’t I will leave with the hardcode values like. The @descirpiton is a Parameter decorators that allow use to add a description of what the parameter is used for.

I create two variables for the vnetId and subnetref that are used for the network interface

Below is what the updated virtual machine resource template looks like.

Once we have the Bicep template file ready the next step is to configure the parameter file. I copied the default template file code from the above Microsoft document and added in each of the required parameters.

To get the virtual network ID that will be used in the parameters file go to the virtual network and click on properties > Resource ID.

Once we have that we can fill out the reset of the parameter values.

After the template file has been configured, we can test the deployment same way as the storage account and use the whatif to confirm there are no errors.

As I have not set the admin password in the template or parameter file the deployment will prompt for the admin password to be set on the VM.

If the test deployment comes back without any issues we can check the results from the whaif deployment to confirm all the are correct.

Since the template and parameter files have returned no error we are ready to run and deploy the new VM resource.

If we check the resource group the new VM, OSDisk and network interface should be created.

Now that we have all the template and parameter file working we can just create a new parameter file for each VM resource. We can now create fully customized VM’s pretty quickly instead of having to deploy using the Azure market place and manually select the options we want to set.

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