284 lines
7.1 KiB
Markdown
284 lines
7.1 KiB
Markdown
# Bootstrapping an H/A Kubernetes Control Plane
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In this lab you will bootstrap a 3 node Kubernetes controller cluster. The following virtual machines will be used:
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```
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NAME ZONE MACHINE_TYPE INTERNAL_IP STATUS
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controller0 us-central1-f n1-standard-1 10.240.0.20 RUNNING
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controller1 us-central1-f n1-standard-1 10.240.0.21 RUNNING
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controller2 us-central1-f n1-standard-1 10.240.0.22 RUNNING
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```
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In this lab you will also create a frontend load balancer with a public IP address for remote access to the API servers and H/A.
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## Why
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The Kubernetes components that make up the control plane include the following components:
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* Kubernetes API Server
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* Kubernetes Scheduler
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* Kubernetes Controller Manager
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Each component is being run on the same machines for the following reasons:
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* The Scheduler and Controller Manager are tightly coupled with the API Server
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* Only one Scheduler and Controller Manager can be active at a given time, but it's ok to run multiple at the same time. Each component will elect a leader via the API Server.
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* Running multiple copies of each component is required for H/A
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* Running each component next to the API Server eases configuration.
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## Provision the Kubernetes Controller Cluster
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Run the following commands on `controller0`, `controller1`, `controller2`:
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> SSH into each machine using the `gcloud compute ssh` command
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Move the TLS certificates in place:
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```
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sudo mkdir -p /var/run/kubernetes
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```
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```
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sudo mv ca.pem kubernetes-key.pem kubernetes.pem /var/run/kubernetes/
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```
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Download and install the Kubernetes controller binaries:
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```
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wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kube-apiserver
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wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kube-controller-manager
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wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kube-scheduler
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wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kubectl
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```
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```
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chmod +x kube-apiserver kube-controller-manager kube-scheduler kubectl
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```
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```
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sudo mv kube-apiserver kube-controller-manager kube-scheduler kubectl /usr/bin/
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```
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#### Kubernetes API Server
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```
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wget https://storage.googleapis.com/hightowerlabs/authorization-policy.jsonl
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```
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```
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cat authorization-policy.jsonl
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```
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```
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sudo mv authorization-policy.jsonl /var/run/kubernetes/
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```
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```
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wget https://storage.googleapis.com/hightowerlabs/token.csv
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```
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```
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cat token.csv
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```
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```
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sudo mv token.csv /var/run/kubernetes/
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```
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Capture the internal IP address:
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```
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export INTERNAL_IP=$(curl -s -H "Metadata-Flavor: Google" \
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http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip)
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```
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Create the systemd unit file:
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```
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cat > kube-apiserver.service <<"EOF"
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[Unit]
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Description=Kubernetes API Server
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Documentation=https://github.com/GoogleCloudPlatform/kubernetes
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[Service]
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ExecStart=/usr/bin/kube-apiserver \
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--admission-control=NamespaceLifecycle,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota \
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--advertise-address=INTERNAL_IP \
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--allow-privileged=true \
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--apiserver-count=3 \
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--authorization-mode=ABAC \
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--authorization-policy-file=/var/run/kubernetes/authorization-policy.jsonl \
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--bind-address=0.0.0.0 \
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--enable-swagger-ui=true \
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--etcd-cafile=/var/run/kubernetes/ca.pem \
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--insecure-bind-address=0.0.0.0 \
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--kubelet-certificate-authority=/var/run/kubernetes/ca.pem \
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--etcd-servers=https://10.240.0.10:2379,https://10.240.0.11:2379,https://10.240.0.12:2379 \
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--service-account-key-file=/var/run/kubernetes/kubernetes-key.pem \
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--service-cluster-ip-range=10.32.0.0/24 \
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--service-node-port-range=30000-32767 \
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--tls-cert-file=/var/run/kubernetes/kubernetes.pem \
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--tls-private-key-file=/var/run/kubernetes/kubernetes-key.pem \
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--token-auth-file=/var/run/kubernetes/token.csv \
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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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```
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sed -i s/INTERNAL_IP/$INTERNAL_IP/g kube-apiserver.service
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```
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```
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sudo mv kube-apiserver.service /etc/systemd/system/
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```
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```
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sudo systemctl daemon-reload
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sudo systemctl enable kube-apiserver
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sudo systemctl start kube-apiserver
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```
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```
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sudo systemctl status kube-apiserver --no-pager
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```
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#### Kubernetes Controller Manager
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```
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cat > kube-controller-manager.service <<"EOF"
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[Unit]
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Description=Kubernetes Controller Manager
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Documentation=https://github.com/GoogleCloudPlatform/kubernetes
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[Service]
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ExecStart=/usr/bin/kube-controller-manager \
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--allocate-node-cidrs=true \
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--cluster-cidr=10.200.0.0/16 \
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--cluster-name=kubernetes \
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--leader-elect=true \
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--master=http://INTERNAL_IP:8080 \
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--root-ca-file=/var/run/kubernetes/ca.pem \
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--service-account-private-key-file=/var/run/kubernetes/kubernetes-key.pem \
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--service-cluster-ip-range=10.32.0.0/24 \
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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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```
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sed -i s/INTERNAL_IP/$INTERNAL_IP/g kube-controller-manager.service
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```
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```
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sudo mv kube-controller-manager.service /etc/systemd/system/
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```
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```
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sudo systemctl daemon-reload
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sudo systemctl enable kube-controller-manager
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sudo systemctl start kube-controller-manager
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```
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```
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sudo systemctl status kube-controller-manager --no-pager
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```
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#### Kubernetes Scheduler
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```
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cat > kube-scheduler.service <<"EOF"
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[Unit]
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Description=Kubernetes Scheduler
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Documentation=https://github.com/GoogleCloudPlatform/kubernetes
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[Service]
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ExecStart=/usr/bin/kube-scheduler \
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--leader-elect=true \
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--master=http://INTERNAL_IP:8080 \
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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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```
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sed -i s/INTERNAL_IP/$INTERNAL_IP/g kube-scheduler.service
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```
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```
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sudo mv kube-scheduler.service /etc/systemd/system/
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```
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```
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sudo systemctl daemon-reload
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sudo systemctl enable kube-scheduler
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sudo systemctl start kube-scheduler
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```
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```
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sudo systemctl status kube-scheduler --no-pager
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```
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#### Verification
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```
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kubectl get componentstatuses
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```
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```
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NAME STATUS MESSAGE ERROR
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controller-manager Healthy ok
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scheduler Healthy ok
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etcd-1 Healthy {"health": "true"}
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etcd-0 Healthy {"health": "true"}
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etcd-2 Healthy {"health": "true"}
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```
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## Setup Kubernetes API Server Frontend Load Balancer
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The virtual machines created in this tutorial will not have permission to complete this section. Run the following commands from the same place used to create the virtual machines for this tutorial.
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```
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gcloud compute http-health-checks create kube-apiserver-check \
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--description "Kubernetes API Server Health Check" \
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--port 8080 \
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--request-path /healthz
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```
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```
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gcloud compute target-pools create kubernetes-pool \
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--region us-central1 \
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--health-check kube-apiserver-check
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```
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```
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gcloud compute target-pools add-instances kubernetes-pool \
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--instances controller0,controller1,controller2
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```
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```
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export KUBERNETES_PUBLIC_IP_ADDRESS=$(gcloud compute addresses describe kubernetes --format 'value(address)')
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```
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```
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gcloud compute forwarding-rules create kubernetes-rule \
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--ports 6443 \
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--address $KUBERNETES_PUBLIC_IP_ADDRESS \
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--target-pool kubernetes-pool
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```
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