86 lines
3.9 KiB
Markdown
86 lines
3.9 KiB
Markdown
---
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title: Set up Konnectivity service
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content_type: task
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weight: 70
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---
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<!-- overview -->
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The Konnectivity service provides a TCP level proxy for the control plane to cluster
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communication.
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## {{% heading "prerequisites" %}}
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You need to have a Kubernetes cluster, and the kubectl command-line tool must
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be configured to communicate with your cluster. It is recommended to run this
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tutorial on a cluster with at least two nodes that are not acting as control
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plane hosts. If you do not already have a cluster, you can create one by using
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[minikube](https://minikube.sigs.k8s.io/docs/tutorials/multi_node/).
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<!-- steps -->
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## Configure the Konnectivity service
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The following steps require an egress configuration, for example:
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{{< codenew file="admin/konnectivity/egress-selector-configuration.yaml" >}}
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You need to configure the API Server to use the Konnectivity service
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and direct the network traffic to the cluster nodes:
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1. Make sure that
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[Service Account Token Volume Projection](/docs/tasks/configure-pod-container/configure-service-account/#service-account-token-volume-projection)
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feature enabled in your cluster. It is enabled by default since Kubernetes v1.20.
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1. Create an egress configuration file such as `admin/konnectivity/egress-selector-configuration.yaml`.
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1. Set the `--egress-selector-config-file` flag of the API Server to the path of
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your API Server egress configuration file.
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1. If you use UDS connection, add volumes config to the kube-apiserver:
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```yaml
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spec:
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containers:
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volumeMounts:
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- name: konnectivity-uds
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mountPath: /etc/kubernetes/konnectivity-server
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readOnly: false
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volumes:
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- name: konnectivity-uds
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hostPath:
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path: /etc/kubernetes/konnectivity-server
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type: DirectoryOrCreate
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```
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Generate or obtain a certificate and kubeconfig for konnectivity-server.
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For example, you can use the OpenSSL command line tool to issue a X.509 certificate,
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using the cluster CA certificate `/etc/kubernetes/pki/ca.crt` from a control-plane host.
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```bash
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openssl req -subj "/CN=system:konnectivity-server" -new -newkey rsa:2048 -nodes -out konnectivity.csr -keyout konnectivity.key -out konnectivity.csr
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openssl x509 -req -in konnectivity.csr -CA /etc/kubernetes/pki/ca.crt -CAkey /etc/kubernetes/pki/ca.key -CAcreateserial -out konnectivity.crt -days 375 -sha256
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SERVER=$(kubectl config view -o jsonpath='{.clusters..server}')
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kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config set-credentials system:konnectivity-server --client-certificate konnectivity.crt --client-key konnectivity.key --embed-certs=true
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kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config set-cluster kubernetes --server "$SERVER" --certificate-authority /etc/kubernetes/pki/ca.crt --embed-certs=true
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kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config set-context system:konnectivity-server@kubernetes --cluster kubernetes --user system:konnectivity-server
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kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config use-context system:konnectivity-server@kubernetes
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rm -f konnectivity.crt konnectivity.key konnectivity.csr
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```
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Next, you need to deploy the Konnectivity server and agents.
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[kubernetes-sigs/apiserver-network-proxy](https://github.com/kubernetes-sigs/apiserver-network-proxy)
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is a reference implementation.
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Deploy the Konnectivity server on your control plane node. The provided
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`konnectivity-server.yaml` manifest assumes
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that the Kubernetes components are deployed as a {{< glossary_tooltip text="static Pod"
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term_id="static-pod" >}} in your cluster. If not, you can deploy the Konnectivity
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server as a DaemonSet.
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{{< codenew file="admin/konnectivity/konnectivity-server.yaml" >}}
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Then deploy the Konnectivity agents in your cluster:
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{{< codenew file="admin/konnectivity/konnectivity-agent.yaml" >}}
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Last, if RBAC is enabled in your cluster, create the relevant RBAC rules:
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{{< codenew file="admin/konnectivity/konnectivity-rbac.yaml" >}}
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