Connect container endpoints to a tenant virtual network

Applies to: Windows Server (Semi-Annual Channel), Windows Server 2016

In this topic, we show you how to connect container endpoints to an existing tenant virtual network created through SDN. You use the l2bridge (and optionally l2tunnel) network driver available with the Windows libnetwork plugin for Docker to create a container network on the tenant VM.

In the Container network drivers topic, we discussed the multiple network drivers are available through Docker on Windows. For SDN, use the l2bridge and l2tunnel drivers. For both drivers, each container endpoint is in the same virtual subnet as the container host (tenant) virtual machine.

The Host Networking Service (HNS), through the private cloud plugin, dynamically assigns the IP addresses for container endpoints. The container endpoints have unique IP addresses but share the same MAC address of the container host (tenant) virtual machine due to Layer-2 address translation.

Network policy (ACLs, encapsulation, and QoS) for these container endpoints are enforced in the physical Hyper-V host as received by the Network Controller and defined in upper-layer management systems.

The difference between the l2bridge and l2tunnel drivers are:

l2bridge l2tunnel
Container endpoints that reside on:
  • The same container host virtual machine and on the same subnet have all network traffic bridged within the Hyper-V virtual switch.
  • Different container host VMs or on different subnets have their traffic forwarded to the physical Hyper-V host.
Network policy does not get enforced since network traffic between containers on the same host and in the same subnet do not flow to the physical host. Network policy applies only to cross-host or cross-subnet container network traffic.
ALL network traffic between two container endpoints is forwarded to the physical Hyper-V host regardless of host or subnet. Network policy applies to both cross-subnet and cross-host network traffic.

Note

These networking modes do not work for connecting windows container endpoints to a tenant virtual network in Azure public cloud.

Prerequisites

  • A deployed SDN infrastructure with the Network Controller.

  • A tenant virtual network has been created.

  • A deployed tenant virtual machine with the Windows Container feature enabled, Docker installed, and Hyper-V feature enabled. The Hyper-V feature is required to install several binaries for l2bridge and l2tunnel networks.

    # To install HyperV feature without checks for nested virtualization
    dism /Online /Enable-Feature /FeatureName:Microsoft-Hyper-V /All 
    

Note

Nested virtualization and exposing virtualization extensions is not required unless using Hyper-V Containers.

Workflow

1. Add multiple IP configurations to an existing VM NIC resource through Network Controller (Hyper-V Host) 2. Enable the network proxy on the host to allocate CA IP Addresses for container endpoints (Hyper-V Host) 3. Install the private cloud plug-in to assign CA IP addresses to container endpoints (Container Host VM) 4. Create an l2bridge or l2tunnel network using docker (Container Host VM)

Note

Multiple IP configurations is not supported on VM NIC resources created through System Center Virtual Machine Manager. It is recommended for these deployments types that you create the VM NIC resource out of band using Network Controller PowerShell.

1. Add Multiple IP Configurations

In this step, we assume the VM NIC of the tenant virtual machine has one IP configuration with IP address of 192.168.1.9 and is attached to a VNet Resource ID of 'VNet1' and VM Subnet Resource of 'Subnet1' in the 192.168.1.0/24 IP subnet. We add 10 IP addresses for containers from 192.168.1.101 - 192.168.1.110.

Import-Module NetworkController

# Specify Network Controller REST IP or FQDN
$uri = "<NC REST IP or FQDN>"
$vnetResourceId = "VNet1"
$vsubnetResourceId = "Subnet1"

$vmnic= Get-NetworkControllerNetworkInterface -ConnectionUri $uri | where {$_.properties.IpConfigurations.Properties.PrivateIPAddress -eq "192.168.1.9" }
$vmsubnet = Get-NetworkControllerVirtualSubnet -VirtualNetworkId $vnetResourceId -ResourceId $vsubnetResourceId -ConnectionUri $uri

# For this demo, we will assume an ACL has already been defined; any ACL can be applied here
$allowallacl = Get-NetworkControllerAccessControlList -ConnectionUri $uri -ResourceId "AllowAll"


foreach ($i in 1..10)
{
    $newipconfig = new-object Microsoft.Windows.NetworkController.NetworkInterfaceIpConfiguration
    $props = new-object Microsoft.Windows.NetworkController.NetworkInterfaceIpConfigurationProperties

    $resourceid = "IP_192_168_1_1"
    if ($i -eq 10) 
    {
        $resourceid += "10"
        $ipstr = "192.168.1.110"
    }
    else
    {
        $resourceid += "0$i"
        $ipstr = "192.168.1.10$i"
    }

    $newipconfig.ResourceId = $resourceid
    $props.PrivateIPAddress = $ipstr    

    $props.PrivateIPAllocationMethod = "Static"
    $props.Subnet = new-object Microsoft.Windows.NetworkController.Subnet
    $props.Subnet.ResourceRef = $vmsubnet.ResourceRef
    $props.AccessControlList = new-object Microsoft.Windows.NetworkController.AccessControlList
    $props.AccessControlList.ResourceRef = $allowallacl.ResourceRef

    $newipconfig.Properties = $props
    $vmnic.Properties.IpConfigurations += $newipconfig
}

New-NetworkControllerNetworkInterface -ResourceId $vmnic.ResourceId -Properties $vmnic.Properties -ConnectionUri $uri

2. Enable the network proxy

In this step, you enable the network proxy to allocate multiple IP addresses for the container host virtual machine.

To enable the network proxy, run the ConfigureMCNP.ps1 script on the Hyper-V Host hosting the container host (tenant) virtual machine.

PS C:\> ConfigureMCNP.ps1

3. Install the Private Cloud plug-in

In this step, you install a plug-in to allow the HNS to communicate with the network proxy on the Hyper-V Host.

To install the plug-in, run the InstallPrivateCloudPlugin.ps1 script inside the container host (tenant) virtual machine.

PS C:\> InstallPrivateCloudPlugin.ps1

4. Create an l2bridge Container Network

In this step, you use the docker network create command on the container host (tenant) virtual machine to create an l2bridge network.

# Create the container network
C:\> docker network create -d l2bridge --subnet="192.168.1.0/24" --gateway="192.168.1.1" MyContainerOverlayNetwork

# Attach a container to the MyContainerOverlayNetwork 
C:\> docker run -it --network=MyContainerOverlayNetwork <image> <cmd>

Note

Static IP assignment is not supported with l2bridge or l2tunnel container networks when used with the Microsoft SDN Stack.

More information

For more details about deploying an SDN infrastructure, see Deploy a Software Defined Network Infrastructure.