Run etcd clusters inside containers

Running etcd with Docker using static bootstrapping

Task

The following guide shows how to run etcd with Docker using the static bootstrap process .

Docker

In order to expose the etcd API to clients outside of Docker host, use the host IP address of the container. Please see docker inspect for more detail on how to get the IP address. Alternatively, specify --net=host flag to docker run command to skip placing the container inside of a separate network stack.

Running a single node etcd

Use the host IP address when configuring etcd:

export NODE1=192.168.1.21

Configure a Docker volume to store etcd data:

docker volume create --name etcd-data
export DATA_DIR="etcd-data"

Run the latest version of etcd (v3.7.0 at the time of writing):

ETCD_VERSION=v3.7.0
REGISTRY=quay.io/coreos/etcd
# available from v3.2.5
REGISTRY=gcr.io/etcd-development/etcd

docker run \
  -p 2379:2379 \
  -p 2380:2380 \
  --volume=${DATA_DIR}:/etcd-data \
  --name etcd ${REGISTRY}:${ETCD_VERSION} \
  /usr/local/bin/etcd \
  --data-dir=/etcd-data --name node1 \
  --initial-advertise-peer-urls http://${NODE1}:2380 --listen-peer-urls http://0.0.0.0:2380 \
  --advertise-client-urls http://${NODE1}:2379 --listen-client-urls http://0.0.0.0:2379 \
  --initial-cluster node1=http://${NODE1}:2380

List the cluster member:

etcdctl --endpoints=http://${NODE1}:2379 member list

Running a 3 node etcd cluster

REGISTRY=quay.io/coreos/etcd
# available from v3.2.5
REGISTRY=gcr.io/etcd-development/etcd

# For each machine
ETCD_VERSION=v3.7.0
TOKEN=my-etcd-token
CLUSTER_STATE=new
NAME_1=etcd-node-0
NAME_2=etcd-node-1
NAME_3=etcd-node-2
HOST_1=10.20.30.1
HOST_2=10.20.30.2
HOST_3=10.20.30.3
CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_3}=http://${HOST_3}:2380
DATA_DIR=/var/lib/etcd

# For node 1
THIS_NAME=${NAME_1}
THIS_IP=${HOST_1}
docker run \
  -p 2379:2379 \
  -p 2380:2380 \
  --volume=${DATA_DIR}:/etcd-data \
  --name etcd ${REGISTRY}:${ETCD_VERSION} \
  /usr/local/bin/etcd \
  --data-dir=/etcd-data --name ${THIS_NAME} \
  --initial-advertise-peer-urls http://${THIS_IP}:2380 --listen-peer-urls http://0.0.0.0:2380 \
  --advertise-client-urls http://${THIS_IP}:2379 --listen-client-urls http://0.0.0.0:2379 \
  --initial-cluster ${CLUSTER} \
  --initial-cluster-state ${CLUSTER_STATE} --initial-cluster-token ${TOKEN}

# For node 2
THIS_NAME=${NAME_2}
THIS_IP=${HOST_2}
docker run \
  -p 2379:2379 \
  -p 2380:2380 \
  --volume=${DATA_DIR}:/etcd-data \
  --name etcd ${REGISTRY}:${ETCD_VERSION} \
  /usr/local/bin/etcd \
  --data-dir=/etcd-data --name ${THIS_NAME} \
  --initial-advertise-peer-urls http://${THIS_IP}:2380 --listen-peer-urls http://0.0.0.0:2380 \
  --advertise-client-urls http://${THIS_IP}:2379 --listen-client-urls http://0.0.0.0:2379 \
  --initial-cluster ${CLUSTER} \
  --initial-cluster-state ${CLUSTER_STATE} --initial-cluster-token ${TOKEN}

# For node 3
THIS_NAME=${NAME_3}
THIS_IP=${HOST_3}
docker run \
  -p 2379:2379 \
  -p 2380:2380 \
  --volume=${DATA_DIR}:/etcd-data \
  --name etcd ${REGISTRY}:${ETCD_VERSION} \
  /usr/local/bin/etcd \
  --data-dir=/etcd-data --name ${THIS_NAME} \
  --initial-advertise-peer-urls http://${THIS_IP}:2380 --listen-peer-urls http://0.0.0.0:2380 \
  --advertise-client-urls http://${THIS_IP}:2379 --listen-client-urls http://0.0.0.0:2379 \
  --initial-cluster ${CLUSTER} \
  --initial-cluster-state ${CLUSTER_STATE} --initial-cluster-token ${TOKEN}

To run etcdctl using API version 3:

docker exec etcd /usr/local/bin/etcdctl put foo bar

Bare Metal

To provision a 3 node etcd cluster on bare-metal, the examples in the baremetal repo may be useful.

Mounting a certificate volume

The etcd release container does not include default root certificates. To use HTTPS with certificates trusted by a root authority (e.g., for discovery), mount a certificate directory into the etcd container:

ETCD_VERSION=v3.7.0
REGISTRY=quay.io/coreos/etcd
# available from v3.2.5
REGISTRY=docker://gcr.io/etcd-development/etcd

rkt run \
  --insecure-options=image \
  --volume etcd-ssl-certs-bundle,kind=host,source=/etc/ssl/certs/ca-certificates.crt \
  --mount volume=etcd-ssl-certs-bundle,target=/etc/ssl/certs/ca-certificates.crt \
  ${REGISTRY}:${ETCD_VERSION} -- --name my-name \
  --initial-advertise-peer-urls http://localhost:2380 --listen-peer-urls http://localhost:2380 \
  --advertise-client-urls http://localhost:2379 --listen-client-urls http://localhost:2379 \
  --discovery https://discovery.etcd.io/c11fbcdc16972e45253491a24fcf45e1

ETCD_VERSION=v3.7.0
REGISTRY=quay.io/coreos/etcd
# available from v3.2.5
REGISTRY=gcr.io/etcd-development/etcd

docker run \
  -p 2379:2379 \
  -p 2380:2380 \
  --volume=/etc/ssl/certs/ca-certificates.crt:/etc/ssl/certs/ca-certificates.crt \
  ${REGISTRY}:${ETCD_VERSION} \
  /usr/local/bin/etcd --name my-name \
  --initial-advertise-peer-urls http://localhost:2380 --listen-peer-urls http://localhost:2380 \
  --advertise-client-urls http://localhost:2379 --listen-client-urls http://localhost:2379 \
  --discovery https://discovery.etcd.io/86a9ff6c8cb8b4c4544c1a2f88f8b801