Upgrade an entire Docker Swarm cluster's `docker.service` settings

update_cluster.sh

#!/bin/sh

pem=${1}
shift
nodes="${@}"

if [ -z ${pem} ] || [ -z "${nodes}" ]; then
    echo "Usage `basename ${0}` <pem-file> <ip1> <ip2> .."
    exit 1
fi

set -e

function _ssh() {
    ip=${1}
    shift
    cmd="${@}"
    echo ""
    echo "Running: ${cmd}"
    ssh -t -o "StrictHostKeyChecking no" -i ${pem} core@${ip} "sudo ${cmd}"
}

for ip in ${nodes}; do

    echo "------ node ${ip} ----------------------------------------"
    # read -p "continue? y/N: " YN
    YN=y    
    if [[ ${YN} =~ [Yy] ]]; then
        confDir=/etc/systemd/system/docker.service.d
        _ssh ${ip} sed -i.bak "'s/--log-driver=journald/--log-driver=json-file --log-opt=max-size=10m --log-opt=max-file=2/'" ${confDir}/20-clct-docker.conf
        # _ssh ${ip} sed -i.bak "'s/--log-driver=json-file --log-opt=max-size=10m --log-opt=max-file=2/--log-driver=journald/'" ${confDir}/20-clct-docker.conf
        _ssh ${ip} systemctl daemon-reload
        _ssh ${ip} systemctl restart docker.service
        _ssh ${ip} systemctl --no-pager status docker.service
        sleep 30
    fi
done

Given that:

• all of a cluster node's public ip addresses are listed in a file called ips.txt
• the pem for the AWS EC2 secret the cluster node's are linked to exists at /creds/services-cluster-nodes.live.pem

Run:

./update_cluster.sh /creds/services-cluster-nodes.live.pem $(cat ips.txt)