VMSS Azure DevOps Agent (Linux)

This contains a Bicep template that will deploy a VMSS suitable for an Azure Devops agent. It is currently configured for use with Terraform but can easily be customised using the cloud-init.yml.

The resulting ARM JSON file is over 700 lines long, this shows how much easier Bicep is to work with!

Features

• Virtual network
  • NSG blocking all inbound connections
• VM Scale Set
  • Managed identity enabled
  • Cloud-init used to install tooling
  • Randomly generated SSH public key used to prevent interactive logins
• Storage account for Terraform backend
  • Azure AD RBAC assigned to VMSS identity
  • Private endpoint and firewall preventing public access
• Key Vault for secrets storage
  • Azure AD RBAC assigned to VMSS identity
  • Private endpoint and firewall preventing public access
• Private DNS zones
  • Zone for blob storage
  • Zone for Key Vault

Usage

# Generate a random SSH public key, discarding the private key
ADMINSSHPUBKEY=$(scripts/generate-random-ssh-pubkey.sh)

# Destination subscription id
# (omit if you want to use the context of az account, remember to remove --subscription from the az command line)
SUBSCRIPTIONID=00000000-0000-0000-0000-000000000000

# Destination region
LOCATION=westeurope

# Resource naming
RESOURCEGROUPNAME=myrg
KEYVAULTNAME=mykv
STORAGEACCOUNTNAME=mystg


az deployment sub create \
    --subscription $SUBSCRIPTIONID \
    --location $LOCATION \
    --template-file bicep/buildagent.bicep \
    --parameters adminSshPubKey="$ADMINSSHPUBKEY" \
                 resourceGroupName=$RESOURCEGROUPNAME \
                 keyVaultName=$KEYVAULTNAME \
                 storageAccountName=$STORAGEACCOUNTNAME

Finally, complete the setup in Azure DevOps to add the VM extension

Azure DevOps Pipeline

See the .azure-pipelines directory for a sample pipeline to deploy this.