gistfile1.txt

#!/bin/bash

read -p "Number of etcd to remain: " ETCD_MEMBERS_KEEP

# scale down CVO and CEO


NODES=($(oc get node -l 'node-role.kubernetes.io/master=' -o 'jsonpath={.items[*].metadata.name}'))

REMAINING_ETCD_NODE=${NODES[-1]}

for (( i=0; i<$ETCD_MEMBERS_KEEP; i++ )); do
  unset NODES[-1]
done

# populate 1mb data file to pipe into etcdctl
oc debug "node/$REMAINING_ETCD_NODE" -- chroot /host /bin/bash -c "dd if=/dev/urandom bs=1000000 count=1 | base64 -w0| sed 's/ //g'| tr -d '\n' > /var/lib/etcd/1mb-data-file"

oc rsh -n openshift-etcd etcd-$REMAINING_ETCD_NODE bash -c 'for key in {1..3000};do etcdctl put /fat/$key < /var/lib/etcd/1mb-data-file;done'

for node in ${NODES[@]}; do

        # get the member id for this node and scale it down.
        id=$(oc rsh -c etcdctl -n openshift-etcd etcd-$node etcdctl member list | grep $node | awk '{print $1}' | tr -d ',')
        echo "scaling down etcd $id on $node"
        oc rsh -c etcdctl -n openshift-etcd etcd-$node etcdctl member remove $id


        # stop etcd static pod.
        echo "stopping etcd on $node";
        oc debug "node/$node" -- chroot /host /bin/bash -c 'sudo -i; mv /etc/kubernetes/manifests/etcd-pod.yaml /tmp'
        sleep 5

        echo "removing etcd data-dir on $node";
        oc debug "node/$node" -- chroot /host /bin/bash -c 'sudo -i;rm -rf /var/lib/etcd'
done

oc rsh -n openshift-etcd etcd-${REMAINING_ETCD_NODE} etcdctl member list -w table

# let cluster settle
sleep 120

# scale back up
oc scale --replicas 1 -n openshift-cluster-version deployments/cluster-version-operator || true
oc scale --replicas 1 -n openshift-etcd-operator deployments/etcd-operator || true

# roll out new etcd
oc patch etcd cluster -p='{"spec": {"forceRedeploymentReason": "rollout-new-'"$( date --rfc-3339=ns )"'"}}' --type=merge