Known issues

MKE 3.5.4 issues for which there are available workaround solutions include:


[MKE-8916] GCP metadata server routes removed on Windows nodes

There is a known issue in Calico wherein Calico removes metadata server routes on Windows nodes, which causes kubelet not to start in Kubernetes. This issue only affects Windows nodes in Kubernetes orchestration mode.

Workaround:

After you install MKE with Windows nodes or join Windows nodes to an existing cluster, manually add the route back to the route table for each Windows instance:

  1. Verify that the route is missing:

    Get-NetRoute
    

    If a route with a DestinationPrefix of 169.254.169.254/32 does not display, you will need to add that route.

  2. Obtain the primary interface where you will add the missing route:

    Get-NetIPInterface -AddressFamily IPv4
    

    Example output:

    ifIndex InterfaceAlias                  AddressFamily NlMtu(Bytes) InterfaceMetric Dhcp     ConnectionState PolicyStore
    ------- --------------                  ------------- ------------ --------------- ----     --------------- -----------
    11      vEthernet (Ethernet) 2          IPv4                  1450               5 Enabled  Connected       ActiveStore
    9       vEthernet (nat)                 IPv4                  1410            5000 Disabled Connected       ActiveStore
    1       Loopback Pseudo-Interface 1     IPv4            4294967295              75 Disabled Connected       ActiveStore
    

    To identify the primary interface:

    1. Ignore the loopback interface.

    2. The primary interface will be connected to the Internet. Use Get-NetRoute to identify the Internet-connected interfaces.

    3. Choose the interface with the lowest InterfaceMetric value.

    In this example, the interface with an ifIndex of 11 is the target interface.

  3. Add the routes, replacing <interface index> with the index or indexes identified in the previous step:

    New-NetRoute -DestinationPrefix "169.254.169.254/32" -InterfaceIndex <interface index> -NextHop 0.0.0.0
    

The kubelet will start and the node will be registered with the API server.


[MKE-8914] Windows Server Core with Containers images incompatible with GCP

As Windows Server Core with Containers images are not compatible with with GCP, their use will prevent kublet from starting up.

Workaround:

Use Windows Server or Windows Server Core images.


[MKE-8814] Mismatched MTU values cause Swarm overlay network issues on GCP

The default MTU value for GCP VPCs is 1460 and the default MTU value for Docker networks is 1500. When left unchanged, components that use Swarm overlay networks fail to communicate with each other.

Workaround:

Do either of the following:

  • Create a new VPC and set the MTU value to 1500.

  • Set the MTU value of the existing VPC to 1500.

For more information, refer to the Google Cloud Platform documentation, Change the MTU setting of a VPC network.