How to set the VNET/SubNet using Azure CLI?

You are right. For some reason az apim create does not provide option to input a subnet reference of a VNET.

You have 2 options:

• Use ARM template. Refer Create an API Management service in External Virtual Network for sample template.

az group deployment create --resource-group <my-resource-group> --template-uri https://raw.githubusercontent.com/Azure/azure-quickstart-templates/master/201-api-management-create-with-external-vnet/azuredeploy.json

Or,

• Use az resource command to add subnet reference after you create APIM.

az apim create --name ${APIMNAME} -g ${RESOURCE_GROUP} -l ${LOCATION} --sku-name ${SKU} --publisher-email ${PUBLISHEREMAIL} --publisher-name ${PUBLISHER} --virtual-network ${APITYPE}

$apimResourceId = az apim show -n ${APIMNAME} -g ${RESOURCE_GROUP} --query 'id' -o json

$subnetResourceId = az network vnet subnet show -g ${RESOURCE_GROUP} -n apim --vnet-name ${VNETNAME} --query 'id' -o json

az resource update --ids $apimResourceId --set properties.virtualNetworkConfiguration.subnetResourceId=$subnetResourceId