this stack contains: Mariadb galera cluster deployed on ETC cluster with docker swarm Memcached server web service (remember to push your own bookface image here and replace it in the docker-compose file) the dockerfile for both memcached(no need to rebuild and push) and web (edit config.php and push) is in a separate folder in this repo. to scale this service use sudo docker service "name of service"=5 (use odd numbers here)

#install centos on wanted number of docker swarm nodes, use centos as password when prompted "open ports 2380, 2399, 2378 and 4001

#install ETCD sudo yum install etcd

#install some needed utilities sudo yum install -y yum-utils
device-mapper-persistent-data
lvm2

#add docker-ce repo

sudo yum-config-manager
--add-repo
https://download.docker.com/linux/centos/docker-ce.repo

#install docker-ce sudo yum install docker-ce sudo systemctl start docker #remember to start docker sudo docker swarm join .... #and to join the swarm

#edit etcd.conf sudo vi /etc/etcd/etcd.conf #its important to comment out EVERY line, or remve them all together before adding the config

ETCD_NAME=etcd1 #name of the given instance, change for second node ETCD_DATA_DIR="/var/lib/etcd/default.etcd" #datadir,default, no need to change ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380" #same for all configs ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379" #same for all configs ETCD_INITIAL_ADVERTISE_PEER_URLS="http://10.10.0.98:2380" #change to the ip of the host (the ip of the machine the config is deployed to)!!! ETCD_INITIAL_CLUSTER="etcd1=http://10.10.0.98:2380,etcd2=http://10.10.0.159:2380,etcd3=http://10.10.1.57:2380,etcd4=http://10.10.1.10:2380" #add all the nodes part of the swarm ETCD_INITIAL_CLUSTER_STATE="new" #no need to change
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster-1" #no need to change ETCD_ADVERTISE_CLIENT_URLS="http://0.0.0.0:2379" #no need to change

#enable etcd

sudo systemctl enable etcd

#check etcd health sudo etcdctl cluster-health sudo etcdctl members curl -L http://127.0.0.1:2379/health

#debugging

systemctl status etcd.service journalctl -u etcd

if encountering and error where the service failes do the following sudo systemctl stop etcd sudo rm -r /var/lib/etcd/default.etcd/member #also if getting mismatched IDs sudo systemctl daemon-reload sudo systemctl start etcd

#docker-compose remember to add your own IP addresses at the discovery address list

if the service of mariadb is not starting, run sudo docker service logs "name of mariadb service" if this is something to do with nt being able to lock on the voulme, run ps aux |grep mysql and kill all mysql processes and deploy the stack again

deploy the stack using

sudo docker stack deploy -c docker-compose.yml

#documentation or further help: https://github.com/severalnines/galera-docker-mariadb https://severalnines.com/blog/mysql-docker-deploy-homogeneous-galera-cluster-etcd https://severalnines.com/blog/mysql-docker-swarm-mode-limitations-galera-cluster-production-setups

The docker compose file uses my own web image with a custom php config image, build your own image and push it to docker hub

docker tag "nameofimage" "dockerhub_user/nameofrepo" docker push dockerhub_user/nameofrepo