The Build Machine Image task makes it easy for users who are new to immutable VHD-based deployments to use Packer without learning concepts such as provisioners and builders. If you are deploying to virtual machines by using deployment scripts, you can use this task for either creating new virtual machine instances or for creating and updating virtual machine scale sets.
The auto-generate mode of the task generates the Packer configuration with:
- Builder for Azure
- Provisioners that depend on the type of base operating system selected. For Linux, this is shell script. For Windows, this is PowerShell script. The deployment script provided is used by the provisioner.
A custom Packer configuration JSON file can also be used.
Get set up
Begin with a CI build
Before you begin, you need a CI build that creates your app. To set up CI, see:
Create the release definition
Open the Releases tab of the Build & Release hub and choose the "+" icon to create a new release definition.
In the Create release definition dialog, select the Empty template and choose Next.
In the next page, select the build definition you created earlier and choose Create. This creates a new release definition with one default environment.
In the new release definition, select + Add tasks and add these task steps:
- Build Machine Image
- Azure PowerShell
The Build Machine Image uses Packer to create a VHD. The entire process is:
- Create a new virtual machine with the selected base operating system
- Install all the prerequisites and the application on the VM by using a deployment script
- Create a VHD and store it in the Azure storage account
- Delete the new virtual machine that was created
Configure the Build Machine Image task as follows:
Task step Parameters
Deploy: Build Machine Image
Build machine image using Packer.
Packer template: You can use your own packer configuration JSON file or use the auto-generate feature where the task generates a packer template for you. This example uses the auto-generated packer configuration.
Azure subscription: Select the Azure service connection you want to use, or create a new service connection.
Storage location: The location of storage account where the VHD will be stored. This should be the same location where the virtual machine scale set is located, or where it will be created.
Base Image Source: You can choose from either a curated gallery of OS images, or provide the URL of your custom image. For example,
Ubuntu 16.04 LTS
Deployment Package: Specify the path of the deployment package directory relative to $(System.DefaultWorkingDirectory). For example,
Deployment Script: Specify the relative path to the PowerShell script (for Windows) or shell script (for Linux) that deploys the package. This script should be within the deployment package path selected above. For example,
Deploy/ubuntu/deployNodejsApp.sh. The script may need to install Curl, Node.js, NGINX, and PM2; copy the application; and then configure NGINX and PM2 to run the application.
Output � Image URL: Provide a name for the output variable that will hold the URL of the generated machine image. For example,
Deploy: Azure PowerShell
Run a PowerShell script to update the Virtual Machine Scale Set with the new VHD.
Azure Connection Type: Select
Azure Resource Manager
Azure RM Subscription: Select the Azure service connection you want to use, or create a new service connection.
Script type: Select
Inline Script: Enter the script shown below to update the virtual machine scale set
Use the following script for the Inline Script parameter of the Azure PowerShell task:
# get the VMSS model $vmss = Get-AzureRmVmss -ResourceGroupName resource_group_name -VMScaleSetName VM_scale_set_name # set the new version in the model data $vmss.virtualMachineProfile.storageProfile.osDisk.image.uri="$(bakedImageUrl)" # update the virtual machine scale set model Update-AzureRmVmss -ResourceGroupName resource_group_name -Name resource_group_name -VirtualMachineScaleSet $vmss
You can use variables to pass values such as the resource group and virtual machine scale set names to the script if you wish.
In the Deployment conditions dialog for the environment, ensure that the Trigger section is set to After release creation.
Enter a name for the release definition and save it.
Create a new release, select the latest build, and ensure that the application has been deployed correctly and has generated the VHD.