Tungsten Fabric known issues and limitations¶

This section lists the Tungsten Fabric known issues with workarounds for the Mirantis OpenStack for Kubernetes release 21.1.

Limitations
[7725] Neutron cannot create networks
[10096] tf-control does not refresh IP addresses of Cassandra pods

Limitations¶

Tungsten Fabric does not provide the following functionality:

Automatic generation of network port records in DNSaaS (Designate) as Neutron with Tungsten Fabric as a backend is not integrated with DNSaaS. As a workaround, you can use the Tungsten Fabric built-in DNS service that enables virtual machines to resolve each other names.
Secret management (Barbican). You cannot use the certificates stored in Barbican to terminate HTTPs in a load balancer.
Role Based Access Control (RBAC) for Neutron objects.

Learn more

Reference Architecture: Tungsten Fabric known limitations

[7725] Neutron cannot create networks¶

^{Fixed in MOS 21.2}

The Neturon service fails to create a network through Horizon and OpenStack CLI throwing the An unknown exception occurred error.

The workaround is to restart the tf-config pods:

Obtain the list of the tf-config pods:
```
kubectl -n tf get pod -l app=tf-config
```

Delete the tf-config-* pods. For example:

kubectl -n tf delete pod tf-config-2whbb

Verify that the pods have been recreated:
```
kubectl -n tf get pod -l app=tf-config
```

[10096] tf-control does not refresh IP addresses of Cassandra pods¶

The tf-control service resolves the DNS names of Cassandra pods at startup and does not update them if Cassandra pods got new IP addresses, for example, in case of a restart. As a workaround, to refresh the IP addresses of Cassandra pods, restart the tf-control pods one by one:

Caution

Before restarting the tf-control pods:

Verify that the new pods are successfully spawned.
Verify that no vRouters are connected to only one tf-control pod that will be restarted.

kubectl -n tf delete pod tf-control-<hash>