4.0 KiB
Bootstrapping the etcd Cluster
Kubernetes components are stateless and store cluster state in etcd. In this lab you will bootstrap a three node etcd cluster and configure it for high availability and secure remote access.
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
Running commands in parallel with tmux
tmux can be used to run commands on multiple compute instances at the same time. See the Running commands in parallel with tmux section in the Prerequisites lab.
Bootstrapping an etcd Cluster Member
Download and Install the etcd Binaries
Download the official etcd release binaries from the etcd GitHub project:
wget -q --show-progress --https-only --timestamping \
"https://github.com/etcd-io/etcd/releases/download/v3.4.14/etcd-v3.4.14-linux-amd64.tar.gz"
Extract and install the etcd
server and the etcdctl
command line utility:
{
tar -xvf etcd-v3.4.14-linux-amd64.tar.gz
sudo mv etcd-v3.4.14-linux-amd64/etcd* /usr/local/bin/
}
Configure the etcd Server
{
sudo mkdir -p /etc/etcd /var/lib/etcd
sudo chmod 700 /var/lib/etcd
sudo cp ca.pem kubernetes-key.pem kubernetes.pem /etc/etcd/
}
The instance internal IP address will be used to serve client requests and communicate with etcd cluster peers. Retrieve the internal IP address for the current compute instance:
INTERNAL_IP=$(curl -s -H "Metadata-Flavor: Google" \
http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip)
Each etcd member must have a unique name within an etcd cluster. Set the etcd name to match the hostname of the current compute instance:
ETCD_NAME=$(hostname -s)
Create the etcd.service
systemd unit file:
cat <<EOF | sudo tee /etc/systemd/system/etcd.service
[Unit]
Description=etcd
Documentation=https://github.com/coreos
[Service]
Type=notify
ExecStart=/usr/local/bin/etcd \\
--name ${ETCD_NAME} \\
--cert-file=/etc/etcd/kubernetes.pem \\
--key-file=/etc/etcd/kubernetes-key.pem \\
--peer-cert-file=/etc/etcd/kubernetes.pem \\
--peer-key-file=/etc/etcd/kubernetes-key.pem \\
--trusted-ca-file=/etc/etcd/ca.pem \\
--peer-trusted-ca-file=/etc/etcd/ca.pem \\
--peer-client-cert-auth \\
--client-cert-auth \\
--initial-advertise-peer-urls https://${INTERNAL_IP}:2380 \\
--listen-peer-urls https://${INTERNAL_IP}:2380 \\
--listen-client-urls https://${INTERNAL_IP}:2379,https://127.0.0.1:2379 \\
--advertise-client-urls https://${INTERNAL_IP}:2379 \\
--initial-cluster-token etcd-cluster-0 \\
--initial-cluster controller-0=https://10.240.0.10:2380,controller-1=https://10.240.0.11:2380,controller-2=https://10.240.0.12:2380 \\
--initial-cluster-state new \\
--data-dir=/var/lib/etcd
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
Start the etcd Server
{
sudo systemctl daemon-reload
sudo systemctl enable etcd
sudo systemctl start etcd
}
Remember to run the above commands on each controller node:
controller-0
,controller-1
, andcontroller-2
.
Verification
List the etcd cluster members:
sudo ETCDCTL_API=3 etcdctl member list \
--endpoints=https://127.0.0.1:2379 \
--cacert=/etc/etcd/ca.pem \
--cert=/etc/etcd/kubernetes.pem \
--key=/etc/etcd/kubernetes-key.pem
output
3a57933972cb5131, started, controller-2, https://10.240.0.12:2380, https://10.240.0.12:2379, false
f98dc20bce6225a0, started, controller-0, https://10.240.0.10:2380, https://10.240.0.10:2379, false
ffed16798470cab5, started, controller-1, https://10.240.0.11:2380, https://10.240.0.11:2379, false