Virtual Networks and Batch Shipyard
The focus of this article is to explain how to bring your own Virtual Network with Batch Shipyard. This will allow you to deploy Batch compute nodes into a subnet within the Virtual Network that you specify.
Batch Account Modes, Configuration and Settings
The following sections will describe the different account modes along with configuration and settings to enable you to deploy Batch compute nodes to an existing Virtual Network.
Choose Your Batch Account Mode
You can bring your own virtual network with either Batch Service and User Subscription Batch accounts. Outside of management of the resources deployed to the subnets, there is no difference in Batch-level functionality. However, it may be more convenient or compliant to use one mode over the other.
Azure Active Directory Authentication Required
Azure Active Directory authentication is required for the
regardless of the account mode. This means that the
credentials configuration file
must include an
aad section with the appropriate options, including the
authentication method of your choosing.
Your service principal requires at least the
Virtual Machine Contributor
role permission or a
custom role with the action:
virtual_network Pool configuration
To deploy Batch compute nodes into a subnet within a Virtual Network that
you specify, you will need to define the
virtual_network property in the
pool configuration file. The template is:
virtual_network: arm_subnet_id: /subscriptions/<subscription_id>/resourceGroups/<resource_group>/providers/Microsoft.Network/virtualNetworks/<virtual_network_name>/subnets/<subnet_name> name: myvnet resource_group: vnet-in-another-rg create_nonexistant: false address_space: 10.0.0.0/16 subnet: name: subnet-for-batch-vms address_prefix: 10.0.0.0/20
If you specify an
arm_subnet_id, then all other options within
virtual_network property are ignored. Your Batch account
must reside within the same subscription and region as the Virtual Network.
If you do not specify an
arm_subnet_id, then you will need to specify
the individual components of the Virtual Network and Subnet in the other
properties. You can also allow Batch Shipyard to create the Virtual Network
on your behalf.
Note: It is recommended to deploy Batch compute nodes in their own exclusive subnet.
If you provide
management credentials, then Batch Shipyard will
automatically validate that the subnet has enough logical IP address space
to fit the desired number of target dedicated and low priority compute nodes.
Note that this calculation does not consider autoscale where the number of
nodes can exceed the specified targets.
Azure provides a resource called a Network Security Group that allows you to define security rules to restrict inbound and outbound network traffic on to the associated resources. A Network Security Group can be attached to one more resources and more than one Network Security Group can work in concert with another Network Security Group operating on a different set of resources within the deployment.
When specifying your own Virtual Network for Batch compute nodes to deploy into, Azure Batch does not modify or create a Network Security Group at the Virtual Network level (associated with subnets). Instead, Azure Batch creates necessary Network Security Groups and attaches them to the individual Network Interfaces for each VM instance within a VM ScaleSet. The Network Security Group that Batch creates will deny any external IP traffic bound for the two required open ports on Azure Batch Virtual Machine configuration compute nodes (the node types used by Batch Shipyard) except for packets originating from the Azure Batch service. Therefore, any external traffic that is routed by the load balancer to the backend NAT pool of virtual machines will be ultimately filtered by this Network Security Group bound for the two required ports.
Network Security Group on the Virtual Network
If you have specified a Network Security Group on the Virtual Network, then
you will need to create a single
Inbound Security Rule to allow traffic
in at the Virtual Network level for Batch compute nodes to successfully
29877 must allow
TCP traffic from any source to any
destination as shown below:
Note that in the aforementioned Network Security, external traffic not originating from the Azure Batch service will be dropped by the Network Security Group Azure Batch deploys on each compute node network interface.
If you wish to apply additional inbound security rules for the remote access
SSH), then you can create an another
Inbound Security Rule
with the destination port range to be
22 and protocol of
TCP. The source
IP address space can be whatever your situation requires. You can even
create a deny rule for this port if you do not want to expose this port and
do not want to configure a software firewall.
Note: Batch compute nodes must be able to communicate with Azure Storage
servers. If you are restricting outbound network traffic through the Network
Security Group, please ensure that oubound
TCP traffic is allowed on port
443 for HTTPS connections. If you are using
Destination Service Tags to
restrict outbound network traffic, ensure that you have either the generic
Storage service tag or the correct
Storage.<region> service tag.
Additionally, ensure that if you are specifying the destination port that
you provide sufficient rules to cover all outbound requests over port
including potentially accesses to other storage regions or any application
logic that may use port
Additional Configuration Documentation
Please see the pool configuration guide for a full explanation of each pool configuration option. Please see the credentials configuration guide for a full explanation of each credential configuration option.