8.0 KiB
Bootstrapping the Kubernetes Control Plane
In this lab you will bootstrap the Kubernetes control plane across three compute instances and configure it for high availability. You will also create an external load balancer that exposes the Kubernetes API Servers to remote clients. The following components will be installed on each node: Kubernetes API Server, Scheduler, and Controller Manager.
Prerequisites
The commands in this lab must be run on each controller instance: controller-0
, controller-1
, and controller-2
. Login to each controller instance using the gcloud
command. Example:
gcloud compute ssh controller-0
Provision the Kubernetes Control Plane
Download and Install the Kubernetes Controller Binaries
Download the official Kubernetes release binaries:
wget -q --show-progress --https-only --timestamping \
"https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kube-apiserver" \
"https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kube-controller-manager" \
"https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kube-scheduler" \
"https://storage.googleapis.com/kubernetes-release/release/v1.7.4/bin/linux/amd64/kubectl"
Install the Kubernetes binaries:
chmod +x kube-apiserver kube-controller-manager kube-scheduler kubectl
sudo mv kube-apiserver kube-controller-manager kube-scheduler kubectl /usr/local/bin/
Configure the Kubernetes API Server
sudo mkdir -p /var/lib/kubernetes/
sudo mv ca.pem ca-key.pem kubernetes-key.pem kubernetes.pem encryption-config.yaml /var/lib/kubernetes/
The instance internal IP address will be used advertise the API Server to members of the cluster. Retrieve the internal IP address for the current compute instance:
INTERNAL_IP=$(curl -s -H "Metadata-Flavor: Google" \
http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip)
Create the kube-apiserver.service
systemd unit file:
cat > kube-apiserver.service <<EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
ExecStart=/usr/local/bin/kube-apiserver \\
--admission-control=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \\
--advertise-address=${INTERNAL_IP} \\
--allow-privileged=true \\
--apiserver-count=3 \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/var/log/audit.log \\
--authorization-mode=Node,RBAC \\
--bind-address=0.0.0.0 \\
--client-ca-file=/var/lib/kubernetes/ca.pem \\
--enable-swagger-ui=true \\
--etcd-cafile=/var/lib/kubernetes/ca.pem \\
--etcd-certfile=/var/lib/kubernetes/kubernetes.pem \\
--etcd-keyfile=/var/lib/kubernetes/kubernetes-key.pem \\
--etcd-servers=https://10.240.0.10:2379,https://10.240.0.11:2379,https://10.240.0.12:2379 \\
--event-ttl=1h \\
--experimental-encryption-provider-config=/var/lib/kubernetes/encryption-config.yaml \\
--insecure-bind-address=0.0.0.0 \\
--kubelet-certificate-authority=/var/lib/kubernetes/ca.pem \\
--kubelet-client-certificate=/var/lib/kubernetes/kubernetes.pem \\
--kubelet-client-key=/var/lib/kubernetes/kubernetes-key.pem \\
--kubelet-https=true \\
--runtime-config=rbac.authorization.k8s.io/v1alpha1 \\
--service-account-key-file=/var/lib/kubernetes/ca-key.pem \\
--service-cluster-ip-range=10.32.0.0/24 \\
--service-node-port-range=30000-32767 \\
--tls-ca-file=/var/lib/kubernetes/ca.pem \\
--tls-cert-file=/var/lib/kubernetes/kubernetes.pem \\
--tls-private-key-file=/var/lib/kubernetes/kubernetes-key.pem \\
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
Configure the Kubernetes Controller Manager
Create the kube-controller-manager.service
systemd unit file:
cat > kube-controller-manager.service <<EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
ExecStart=/usr/local/bin/kube-controller-manager \\
--address=0.0.0.0 \\
--cluster-cidr=10.200.0.0/16 \\
--cluster-name=kubernetes \\
--cluster-signing-cert-file=/var/lib/kubernetes/ca.pem \\
--cluster-signing-key-file=/var/lib/kubernetes/ca-key.pem \\
--leader-elect=true \\
--master=http://${INTERNAL_IP}:8080 \\
--root-ca-file=/var/lib/kubernetes/ca.pem \\
--service-account-private-key-file=/var/lib/kubernetes/ca-key.pem \\
--service-cluster-ip-range=10.32.0.0/16 \\
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
Configure the Kubernetes Scheduler
Create the kube-scheduler.service
systemd unit file:
cat > kube-scheduler.service <<EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
ExecStart=/usr/local/bin/kube-scheduler \\
--leader-elect=true \\
--master=http://${INTERNAL_IP}:8080 \\
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
Start the Controller Services
sudo mv kube-apiserver.service kube-scheduler.service kube-controller-manager.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable kube-apiserver kube-controller-manager kube-scheduler
sudo systemctl start kube-apiserver kube-controller-manager kube-scheduler
Allow up to 10 seconds for the Kubernetes API Server to fully initialize.
Verification
kubectl get componentstatuses
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-2 Healthy {"health": "true"}
etcd-0 Healthy {"health": "true"}
etcd-1 Healthy {"health": "true"}
Remember to run the above commands on each controller node:
controller-0
,controller-1
, andcontroller-2
.
The Kubernetes Frontend Load Balancer
In this section you will provision an external load balancer to front the Kubernetes API Servers. The kubernetes-the-hard-way
static IP address will be attached to the resulting load balancer.
The compute instances created in this tutorial will not have permission to complete this section. Run the following commands from the same machine used to create the compute instances.
Create the external load balancer network resources:
gcloud compute http-health-checks create kube-apiserver-health-check \
--description "Kubernetes API Server Health Check" \
--port 8080 \
--request-path /healthz
gcloud compute target-pools create kubernetes-target-pool \
--http-health-check=kube-apiserver-health-check
gcloud compute target-pools add-instances kubernetes-target-pool \
--instances controller-0,controller-1,controller-2
KUBERNETES_PUBLIC_ADDRESS=$(gcloud compute addresses describe kubernetes-the-hard-way \
--region $(gcloud config get-value compute/region) \
--format 'value(name)')
gcloud compute forwarding-rules create kubernetes-forwarding-rule \
--address ${KUBERNETES_PUBLIC_ADDRESS} \
--ports 6443 \
--region $(gcloud config get-value compute/region) \
--target-pool kubernetes-target-pool
Verification
Retrieve the kubernetes-the-hard-way
static IP address:
KUBERNETES_PUBLIC_ADDRESS=$(gcloud compute addresses describe kubernetes-the-hard-way \
--region $(gcloud config get-value compute/region) \
--format 'value(address)')
Make a HTTP request for the Kubernetes version info:
curl --cacert ca.pem https://${KUBERNETES_PUBLIC_ADDRESS}:6443/version
output
{
"major": "1",
"minor": "7",
"gitVersion": "v1.7.4",
"gitCommit": "793658f2d7ca7f064d2bdf606519f9fe1229c381",
"gitTreeState": "clean",
"buildDate": "2017-08-17T08:30:51Z",
"goVersion": "go1.8.3",
"compiler": "gc",
"platform": "linux/amd64"
}