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