k8s thw 08 - bootstrapping controllers
bootstrapping the kubernetes control plane
the following commands have to execute on each master instance
get the kubernetes controller
binaries
# create kubernetes config dir
> sudo mkdir -p /etc/kubernetes/config
# get kubectl, kube-apiserver, kube-controller-manager
> wget -q --show-progress --https-only --timestamping \
"https://storage.googleapis.com/kubernetes-release/release/v1.13.0/bin/linux/amd64/kube-apiserver" \
"https://storage.googleapis.com/kubernetes-release/release/v1.13.0/bin/linux/amd64/kube-controller-manager" \
"https://storage.googleapis.com/kubernetes-release/release/v1.13.0/bin/linux/amd64/kube-scheduler" \
"https://storage.googleapis.com/kubernetes-release/release/v1.13.0/bin/linux/amd64/kubectl"
# make them executable and move to /usr/local/bin/
> {
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
# create /var/lib/kubernetes and copy certs in
{
sudo mkdir -p /var/lib/kubernetes/
sudo cp ca.crt ca.key kube-apiserver.crt kube-apiserver.key \
service-account.key service-account.crt \
etcd-server.key etcd-server.crt \
encryption-config.yaml /var/lib/kubernetes/
}
# set internal ip env
> INTERNAL_IP=$(ip addr show enp0s8 | grep "inet " | awk '{print $2}' | cut -d / -f 1)
# print env
echo $INTERNAL_IP
create the kube-apiserver.service
systemd unit file
cat <<EOF | sudo tee /etc/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
[Service]
ExecStart=/usr/local/bin/kube-apiserver \\
--advertise-address=${INTERNAL_IP} \\
--allow-privileged=true \\
--apiserver-count=2 \\
--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.crt \\
--enable-admission-plugins=NodeRestriction,ServiceAccount \\
--enable-swagger-ui=true \\
--enable-bootstrap-token-auth=true \\
--etcd-cafile=/var/lib/kubernetes/ca.crt \\
--etcd-certfile=/var/lib/kubernetes/etcd-server.crt \\
--etcd-keyfile=/var/lib/kubernetes/etcd-server.key \\
--etcd-servers=https://192.168.5.11:2379,https://192.168.5.12:2379 \\
--event-ttl=1h \\
--encryption-provider-config=/var/lib/kubernetes/encryption-config.yaml \\
--kubelet-certificate-authority=/var/lib/kubernetes/ca.crt \\
--kubelet-client-certificate=/var/lib/kubernetes/kube-apiserver.crt \\
--kubelet-client-key=/var/lib/kubernetes/kube-apiserver.key \\
--kubelet-https=true \\
--runtime-config=api/all=true \\
--service-account-key-file=/var/lib/kubernetes/service-account.crt \\
--service-cluster-ip-range=10.96.0.0/24 \\
--service-node-port-range=30000-32767 \\
--tls-cert-file=/var/lib/kubernetes/kube-apiserver.crt \\
--tls-private-key-file=/var/lib/kubernetes/kube-apiserver.key \\
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
configure the kubernetes controller
manager
copy the kube-controller-manager
kubeconfig into place
> sudo cp kube-controller-manager.kubeconfig /var/lib/kubernetes/
create the kube-controller-manager.service
systemd unit file
cat <<EOF | sudo tee /etc/systemd/system/kube-controller-manager.service
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
[Service]
ExecStart=/usr/local/bin/kube-controller-manager \\
--address=0.0.0.0 \\
--cluster-cidr=192.168.5.0/24 \\
--cluster-name=kubernetes \\
--cluster-signing-cert-file=/var/lib/kubernetes/ca.crt \\
--cluster-signing-key-file=/var/lib/kubernetes/ca.key \\
--kubeconfig=/var/lib/kubernetes/kube-controller-manager.kubeconfig \\
--leader-elect=true \\
--root-ca-file=/var/lib/kubernetes/ca.crt \\
--service-account-private-key-file=/var/lib/kubernetes/service-account.key \\
--service-cluster-ip-range=10.96.0.0/24 \\
--use-service-account-credentials=true \\
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
configure the kubernetes scheduler
copy the kube-scheduler
kubeconfig into place
> sudo cp kube-scheduler.kubeconfig /var/lib/kubernetes/
create the kube-scheduler.service
systemd unit file
cat <<EOF | sudo tee /etc/systemd/system/kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
ExecStart=/usr/local/bin/kube-scheduler \\
--kubeconfig=/var/lib/kubernetes/kube-scheduler.kubeconfig \\
--address=127.0.0.1 \\
--leader-elect=true \\
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
start the controller
services
# reload systemd, reload and enable sheduler and api server
{
sudo systemctl daemon-reload
sudo systemctl enable kube-apiserver kube-controller-manager kube-scheduler
sudo systemctl start kube-apiserver kube-controller-manager kube-scheduler
}
verify components
> kubectl get componentstatuses --kubeconfig admin.kubeconfig
---
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-0 Healthy {"health": "true"}
etcd-1 Healthy {"health": "true"}
the kubernetes frontend load balancer
Login to the loadbalance
instance
# install required software for load balancing
> sudo apt-get update && sudo apt-get install -y haproxy
create haproxy
configuration
cat <<EOF | sudo tee /etc/haproxy/haproxy.cfg
frontend kubernetes
bind 192.168.5.30:6443
option tcplog
mode tcp
default_backend kubernetes-master-nodes
backend kubernetes-master-nodes
mode tcp
balance roundrobin
option tcp-check
server master-1 192.168.5.11:6443 check fall 3 rise 2
server master-2 192.168.5.12:6443 check fall 3 rise 2
EOF
start haproxy
service
> sudo service haproxy restart
verificate - show kubernetes version
> curl https://192.168.5.30:6443/version -k
{
"major": "1",
"minor": "13",
"gitVersion": "v1.13.0",
"gitCommit": "ddf47ac13c1a9483ea035a79cd7c10005ff21a6d",
"gitTreeState": "clean",
"buildDate": "2018-12-03T20:56:12Z",
"goVersion": "go1.11.2",
"compiler": "gc",
"platform": "linux/amd64"
— copyleft —
all commands shown on this page are from
mmumshad’s fork of “kubernetes-the-hard-way” by kelseyhightower
on github
19-09-2021