Enable kubectl to manage Calico APIs (tech-preview)

3 MINUTE READ

Big picture

[ Feature status: Tech-preview in v3.19 ]

Install the Calico API server on an existing cluster to enable management of Calico APIs using kubectl.

Warning! The Calico API server is a tech preview feature and should not be used in production clusters. It has had limited testing and is liable to change in future releases. Please provide feedback and issue reports via GitHub.

Value

Normally, calicoctl is required in order to manage Calico APIs in the projectcalico.org/v3 API group. The API server provides a REST API for Calico, and allows management of these APIs using kubectl instead.

Before you begin

  • A cluster with Calico installed using the Kubernetes API data store.

  • A machine with openssl installed.

Concepts

calicoctl vs kubectl

In previous releases, calicoctl has been required to manage Calico API resources in the projectcalico.org/v3 API group. The calicoctl CLI tool provides important validation and defaulting on these APIs. The Calico API server performs that defaulting and validation server-side, exposing the same API semantics without a dependency on calicoctl.

calicoctl is still required for the following subcommands:

How to

Install the API server

  1. Create the following manifest, which will install the API server as a deployment in the calico-apiserver namespace.

    kubectl create -f https://docs.projectcalico.org/manifests/apiserver.yaml
    

    You will notice that the API server remains in a ContainerCreating state, as it is waiting for credentials to be provided for authenticating the main Kubernetes API server.

  2. Generate a private key and CA bundle using the following openssl command. This certificate will be used by the main API server to authenticate with the Calico API server.

    Note: Please note in the following command -addext argument requires openssl 1.1.1 or above. You can check your version of openssl using openssl version.

    openssl req -x509 -nodes -newkey rsa:4096 -keyout apiserver.key -out apiserver.crt -days 365 -subj "/" -addext "subjectAltName = DNS:calico-api.calico-apiserver.svc"
    
  3. Provide the key and certificate to the Calico API server as a Kubernetes secret.

    kubectl create secret -n calico-apiserver generic calico-apiserver-certs --from-file=apiserver.key --from-file=apiserver.crt
    
  4. Configure the main API server with the CA bundle.

    kubectl patch apiservice v3.projectcalico.org -p \
        "{\"spec\": {\"caBundle\": \"$(kubectl get secret -n calico-apiserver calico-apiserver-certs -o go-template='{{ index .data "apiserver.crt" }}')\"}}"
    

    You should see the API server pod become ready, and Calico API resources become available. You can check whether the APIs are available with the following command:

    kubectl api-resources | grep '\sprojectcalico.org'
    

    You should see the following output:

    bgpconfigurations                 bgpconfig,bgpconfigs                            projectcalico.org              false        BGPConfiguration
    bgppeers                                                                          projectcalico.org              false        BGPPeer
    clusterinformations               clusterinfo                                     projectcalico.org              false        ClusterInformation
    felixconfigurations               felixconfig,felixconfigs                        projectcalico.org              false        FelixConfiguration
    globalnetworkpolicies             gnp,cgnp,calicoglobalnetworkpolicies            projectcalico.org              false        GlobalNetworkPolicy
    globalnetworksets                                                                 projectcalico.org              false        GlobalNetworkSet
    hostendpoints                     hep,heps                                        projectcalico.org              false        HostEndpoint
    ippools                                                                           projectcalico.org              false        IPPool
    kubecontrollersconfigurations                                                     projectcalico.org              false        KubeControllersConfiguration
    networkpolicies                   cnp,caliconetworkpolicy,caliconetworkpolicies   projectcalico.org              true         NetworkPolicy
    networksets                       netsets                                         projectcalico.org              true         NetworkSet
    profiles                                                                          projectcalico.org              false        Profile
    

Note: kubectl may continue to prefer the crd.projectcalico.org API group due to the way it caches APIs locally. You can force kubectl to update by removing its cache directory for your cluster. By default, the cache is located in $(HOME)/.kube/cache.

Use kubectl for projectcalico.org APIs

Once the API server has been installed, you can use kubectl to interact with the Calico APIs. For example, you can view and edit IP pools.

   kubectl get ippools

You should see output that looks like this:

   NAME                  CREATED AT
   default-ipv4-ippool   2021-03-19T16:47:12Z 

Uninstall the Calico API server

To uninstall, delete the API server manifest.

   kubectl delete -f https://docs.projectcalico.org/manifests/apiserver.yaml

Once removed, you will need to use calicoctl to manage projectcalico.org/v3 APIs.

Next steps

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