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
[MKE-8914] Windows Server Core with Containers images incompatible with GCP
[MKE-8814] Mismatched MTU values cause Swarm overlay network issues on GCP
[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:
Verify that the route is missing:
Get-NetRoute
If a route with a
DestinationPrefix
of169.254.169.254/32
does not display, you will need to add that route.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:
Ignore the
loopback
interface.The primary interface will be connected to the Internet. Use
Get-NetRoute
to identify the Internet-connected interfaces.Choose the interface with the lowest
InterfaceMetric
value.
In this example, the interface with an
ifIndex
of 11 is the target interface.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.