Workbench Launching to Multiple Kubernetes Clusters

Is it possible to select from multiple Kubernetes clusters when launching a session from Workbench?

Yes, it is possible to have multiple Kubernetes clusters on a single Workbench instance. As long the two clusters can talk to each other, the Workbench instance can launch a session on a choice of multiple Kubernetes clusters. You can use the /etc/rstudio/launcher.kubernetes.conf file to target a Kubernetes in a single node cluster.

See the example below for a workbench instance that uses two separate Kubernetes clusters. First, in the /etc/rstudio/launcher.conf configuration file, you will need to specify two different clusters. It is important to specify a unique config-file for each cluster. See the example below for how this can look:

[server]
address=127.0.0.1
port=5559
server-user=rstudio-server
admin-group=rstudio-server
authorization-enabled=1
thread-pool-size=4
enable-debug-logging=1

[cluster]
name=KubesOne
type=Kubernetes
config-file=/etc/rstudio/launcher.kubes.one.conf

[cluster]
name=KubesTwo
type=Kubernetes
config-file=/etc/rstudio/launcher.kubes.two.conf

 
Then, create two Kubernetes configuration files, with the profile-config configuration added to point to a unique profile file. See the /etc/rstudio/launcher.kubes.one.conf file below as an example:

api-url=<KUBERNETES-API-ENDPOINT>
auth-token=<KUBERNETES-CLUSTER-TOKEN>
certificate-authority=<BASE-64-ENCODED-CA-CERTIFICATE>
profile-config=/etc/rstudio/launcher.kubes.one.profiles.conf

From there, you can edit the/etc/rstudio/launcher.kubes.two.conf file as a small example:

api-url=<KUBERNETES-API-ENDPOINT>
auth-token=<KUBERNETES-CLUSTER-TOKEN>
certificate-authority=<BASE-64-ENCODED-CA-CERTIFICATE>
profile-config=/etc/rstudio/launcher.kubes.two.profiles.conf

Then, configure two profile Kubernetes profiles with the resources allowed for the different environments. Here is an example for the /etc/rstudio/launcher.kubes.one.profiles.conf configuration file which allows for a larger pod size:

[*]
default-cpus=1
default-mem-mb=1024
max-cpus=4
max-mem-mb=4096
container-images=rstudio/r-session-complete:centos7-2021.09.2-382.pro1
default-container-image=rstudio/r-session-complete:centos7-2021.09.2-382.pro1
allow-unknown-images=0

See this example for /etc/rstudio/launcher.kubes.two.profiles.conf configuration file:

[*]
default-cpus=4
default-mem-mb=4096
max-cpus=8
max-mem-mb=8192
container-images=rstudio/r-session-complete:centos7-2021.09.2-382.pro1
default-container-image=rstudio/r-session-complete:centos7-2021.09.2-382.pro1
allow-unknown-images=0

 
One last thing to note, if the different clusters require different types of storage mounts, then you'll need to add unique mount configurations in the /etc/rstudio/launcher-mounts configuration file:

Host: <NFS-IP-ADDRESS>
Path: /home/{USER}
MountPath: /home/{USER}
ReadOnly: false
Cluster: KubesOne

Host: <NFS-IP-ADDRESS>
Path: /home/{USER}
MountPath: /home/{USER}
ReadOnly: false
Cluster: KubesTwo

 
Or if the clusters will use the same mounts, then one mount definition with no cluster configuration will work:

Host: <NFS-IP-ADDRESS>
Path: /home/{USER}
MountPath: /home/{USER}
ReadOnly: false

Support Ticket

If you still have issues after completing the above, you can always lodge a support ticket, where our group of friendly, and incredibly knowledgeable staff can assist with any issues that you may be having. You can submit a ticket here:

https://support.rstudio.com/hc/en-us/requests/new