Install an unmanaged CNI plugin

Estimated reading time: 4 minutes

For Docker Universal Control Plane (UCP), Calico provides the secure networking functionality for container-to-container communication within Kubernetes. UCP handles the lifecycle of Calico and packages it with UCP installation and upgrade. Additionally, the Calico deployment included with UCP is fully supported with Docker providing guidance on the CNI components.

At install time, UCP can be configured to install an alternative CNI plugin to support alternative use cases. The alternative CNI plugin is certified by Docker and its partners, and published on Docker Hub. UCP components are still fully supported by Docker and respective partners. Docker will provide pointers to basic configuration, however for additional guidance on managing third party CNI components, the platform operator will need to refer to the partner documentation or contact that third party.

Install an unmanaged CNI plugin on Docker UCP

Once a platform operator has complied with UCP system requirements and taken into consideration any requirements for the custom CNI plugin, you can run the UCP install command with the --unmanaged-cni flag to bring up the platform.

This command will install UCP, and bring up components like the user interface and the RBAC engine. UCP components that require Kubernetes Networking, such as Metrics, will not start and will stay in a Container Creating state in Kubernetes, until a CNI is installed.

Install UCP without a CNI plugin

Once connected to a manager node with the Docker Enterprise Engine installed, you are ready to install UCP with the --unmanaged-cni flag.

docker container run --rm -it --name ucp \
  -v /var/run/docker.sock:/var/run/docker.sock \
  docker/ucp:3.2.1 install \
  --host-address <node-ip-address> \
  --unmanaged-cni \
  --interactive

Once the installation is complete, you will be able to access UCP in the browser. Note that the manager node will be unhealthy as the kubelet will report NetworkPluginNotReady. Additionally, the metrics in the UCP dashboard will also be unavailable, as this runs in a Kubernetes pod.

Configure CLI access to UCP

Next, a platform operator should log into UCP, download a UCP client bundle, and configure the Kubernetes CLI tool, kubectl. See CLI Based Access for more details.

With kubectl, you can see that the UCP components running on Kubernetes are still pending, waiting for a CNI driver before becoming available.

$ kubectl get nodes
NAME         STATUS     ROLES     AGE       VERSION
manager-01   NotReady   master    10m       v1.11.9-docker-1
  
$ kubectl get pods -n kube-system -o wide
NAME                           READY     STATUS              RESTARTS   AGE       IP        NODE         NOMINATED NODE
compose-565f7cf9ff-gq2gv       0/1       Pending             0          10m       <none>    <none>       <none>
compose-api-574d64f46f-r4c5g   0/1       Pending             0          10m       <none>    <none>       <none>
kube-dns-6d96c4d9c6-8jzv7      0/3       Pending             0          10m       <none>    <none>       <none>
ucp-metrics-nwt2z              0/3       ContainerCreating   0          10m       <none>    manager-01   <none>

Install an unmanaged CNI plugin

You can usekubectl to install a custom CNI plugin on UCP. Alternative CNI plugins are Weave, Flannel, Canal, Romana and many more. Platform operators have complete flexibility on what to install, but Docker will not support the CNI plugin.

The steps for installing a CNI plugin typically include:

  • Downloading the relevant upstream CNI binaries from https://github.com/containernetworking/cni/releases/tag/
  • Placing them in /opt/cni/bin
  • Downloading the relevant CNI plugin’s Kubernetes Manifest YAML, and
  • Running $ kubectl apply -f <your-custom-cni-plugin>.yaml

Follow the CNI plugin documentation for specific installation instructions.

While troubleshooting a custom CNI plugin, you may wish to access logs within the kubelet. Connect to a UCP manager node and run $ docker logs ucp-kubelet.

Verify the UCP installation

Upon successful installation of the CNI plugin, the related UCP components should have a Running status as pods start to become available.

$ kubectl get pods -n kube-system -o wide
NAME                           READY     STATUS    RESTARTS   AGE       IP            NODE         NOMINATED NODE
compose-565f7cf9ff-gq2gv       1/1       Running   0          21m       10.32.0.2     manager-01   <none>
compose-api-574d64f46f-r4c5g   1/1       Running   0          21m       10.32.0.3     manager-01   <none>
kube-dns-6d96c4d9c6-8jzv7      3/3       Running   0          22m       10.32.0.5     manager-01   <none>
ucp-metrics-nwt2z              3/3       Running   0          22m       10.32.0.4     manager-01   <none>
weave-net-wgvcd                2/2       Running   0          8m        172.31.6.95   manager-01   <none>

Note: The above example deployment uses Weave. If you are using an alternative CNI plugin, look for the relevant name and review its status.

Where to go next

ucp, kubernetes, cni, container networking interface, flannel, weave, calico