297 lines
6.4 KiB
Markdown
297 lines
6.4 KiB
Markdown
# Bootstrapping the Kubernetes Worker Nodes
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In this lab you will bootstrap three Kubernetes worker nodes. The following components will be installed on each node: [runc](https://github.com/opencontainers/runc), [container networking plugins](https://github.com/containernetworking/cni), [cri-o](https://github.com/kubernetes-incubator/cri-o), [kubelet](https://kubernetes.io/docs/admin/kubelet), and [kube-proxy](https://kubernetes.io/docs/concepts/cluster-administration/proxies).
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## Prerequisites
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The commands in this lab must be run on each worker instance: `worker-0`, `worker-1`, and `worker-2`. Login to each worker instance using the `gcloud` command. Example:
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```
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gcloud compute ssh worker-0
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```
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## Provisioning a Kubernetes Worker Node
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### Install the cri-o OS Dependencies
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Add the `alexlarsson/flatpak` [PPA](https://launchpad.net/ubuntu/+ppas) which hosts the `libostree` package:
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`libostree` is provided by the `ostree` RPM on RHEL7.
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```
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sudo add-apt-repository -y ppa:alexlarsson/flatpak
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```
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```
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sudo apt-get update
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```
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Install the OS dependencies required by the cri-o container runtime:
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```
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sudo apt-get install -y socat libgpgme11 libostree-1-1
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```
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For RHEL, run:
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```
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sudo yum install -y socat device-mapper-libs ostree
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```
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Also for RHEL, the specific library version used to build crio has not yet been released. For now, symlink like so:
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```
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sudo ln -s /usr/lib64/libdevmapper.so.1.02 /usr/lib64/libdevmapper.so.1.02.1
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```
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### Download and Install Worker Binaries
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```
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curl \
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-O https://github.com/containernetworking/plugins/releases/download/v0.6.0/cni-plugins-amd64-v0.6.0.tgz \
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-O https://github.com/opencontainers/runc/releases/download/v1.0.0-rc4/runc.amd64 \
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-O https://storage.googleapis.com/kubernetes-the-hard-way/crio-amd64-v1.0.0-beta.0.tar.gz \
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-O https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kubectl \
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-O https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kube-proxy \
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-O https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kubelet
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```
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Create the installation directories:
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```
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sudo mkdir -p \
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/etc/containers \
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/etc/cni/net.d \
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/etc/crio \
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/opt/cni/bin \
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/usr/local/libexec/crio \
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/var/lib/kubelet \
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/var/lib/kube-proxy \
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/var/lib/kubernetes \
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/var/run/kubernetes
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```
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Install the worker binaries:
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```
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sudo tar -xvf cni-plugins-amd64-v0.6.0.tgz -C /opt/cni/bin/
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```
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```
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tar -xvf crio-amd64-v1.0.0-beta.0.tar.gz
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```
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```
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chmod +x kubectl kube-proxy kubelet runc.amd64
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```
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```
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sudo mv runc.amd64 /usr/local/bin/runc
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```
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```
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sudo mv crio crioctl kpod kubectl kube-proxy kubelet /usr/local/bin/
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```
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```
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sudo mv conmon pause /usr/local/libexec/crio/
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```
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### Configure CNI Networking
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Retrieve the Pod CIDR range for the current compute instance:
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```
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POD_CIDR=$(curl -s -H "Metadata-Flavor: Google" \
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http://metadata.google.internal/computeMetadata/v1/instance/attributes/pod-cidr)
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```
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Create the `bridge` network configuration file:
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```
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cat > 10-bridge.conf <<EOF
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{
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"cniVersion": "0.3.1",
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"name": "bridge",
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"type": "bridge",
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"bridge": "cnio0",
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"isGateway": true,
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"ipMasq": true,
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"ipam": {
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"type": "host-local",
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"ranges": [
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[{"subnet": "${POD_CIDR}"}]
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],
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"routes": [{"dst": "0.0.0.0/0"}]
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}
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}
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EOF
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```
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Create the `loopback` network configuration file:
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```
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cat > 99-loopback.conf <<EOF
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{
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"cniVersion": "0.3.1",
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"type": "loopback"
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}
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EOF
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```
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Move the network configuration files to the CNI configuration directory:
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```
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sudo mv 10-bridge.conf 99-loopback.conf /etc/cni/net.d/
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```
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### Configure the CRI-O Container Runtime
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```
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sudo mv crio.conf seccomp.json /etc/crio/
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```
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```
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sudo mv policy.json /etc/containers/
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```
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```
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cat > crio.service <<EOF
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[Unit]
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Description=CRI-O daemon
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Documentation=https://github.com/kubernetes-incubator/cri-o
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[Service]
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ExecStart=/usr/local/bin/crio
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Restart=always
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RestartSec=10s
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[Install]
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WantedBy=multi-user.target
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EOF
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```
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### Configure the Kubelet
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```
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sudo mv ${HOSTNAME}-key.pem ${HOSTNAME}.pem /var/lib/kubelet/
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```
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```
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sudo mv ${HOSTNAME}.kubeconfig /var/lib/kubelet/kubeconfig
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```
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```
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sudo mv ca.pem /var/lib/kubernetes/
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```
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Create the `kubelet.service` systemd unit file:
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```
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cat > kubelet.service <<EOF
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[Unit]
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Description=Kubernetes Kubelet
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Documentation=https://github.com/GoogleCloudPlatform/kubernetes
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After=crio.service
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Requires=crio.service
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[Service]
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ExecStart=/usr/local/bin/kubelet \\
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--allow-privileged=true \\
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--cluster-dns=10.32.0.10 \\
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--cluster-domain=cluster.local \\
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--container-runtime=remote \\
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--container-runtime-endpoint=unix:///var/run/crio.sock \\
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--enable-custom-metrics \\
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--image-pull-progress-deadline=2m \\
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--image-service-endpoint=unix:///var/run/crio.sock \\
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--kubeconfig=/var/lib/kubelet/kubeconfig \\
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--network-plugin=cni \\
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--pod-cidr=${POD_CIDR} \\
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--register-node=true \\
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--require-kubeconfig \\
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--runtime-request-timeout=10m \\
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--tls-cert-file=/var/lib/kubelet/${HOSTNAME}.pem \\
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--tls-private-key-file=/var/lib/kubelet/${HOSTNAME}-key.pem \\
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--v=2
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Restart=on-failure
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RestartSec=5
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[Install]
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WantedBy=multi-user.target
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EOF
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```
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### Configure the Kubernetes Proxy
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```
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sudo mv kube-proxy.kubeconfig /var/lib/kube-proxy/kubeconfig
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```
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Create the `kube-proxy.service` systemd unit file:
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```
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cat > kube-proxy.service <<EOF
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[Unit]
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Description=Kubernetes Kube Proxy
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Documentation=https://github.com/GoogleCloudPlatform/kubernetes
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[Service]
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ExecStart=/usr/local/bin/kube-proxy \\
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--cluster-cidr=10.200.0.0/16 \\
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--kubeconfig=/var/lib/kube-proxy/kubeconfig \\
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--proxy-mode=iptables \\
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--v=2
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Restart=on-failure
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RestartSec=5
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[Install]
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WantedBy=multi-user.target
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EOF
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```
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### Start the Worker Services
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```
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sudo mv crio.service kubelet.service kube-proxy.service /etc/systemd/system/
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```
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```
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sudo systemctl daemon-reload
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```
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```
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sudo systemctl enable crio kubelet kube-proxy
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```
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```
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sudo systemctl start crio kubelet kube-proxy
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```
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> Remember to run the above commands on each worker node: `worker-0`, `worker-1`, and `worker-2`.
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## Verification
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Login to one of the controller nodes:
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```
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gcloud compute ssh controller-0
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```
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List the registered Kubernetes nodes:
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```
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kubectl get nodes
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```
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> output
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```
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NAME STATUS AGE VERSION
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worker-0 Ready 5m v1.7.4
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worker-1 Ready 3m v1.7.4
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worker-2 Ready 7s v1.7.4
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```
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Next: [Configuring kubectl for Remote Access](10-configuring-kubectl.md)
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