MariaDB Galera Cluster in Docker Containers

This repository maintains the Dockerfile and scripts to build MariaDB Galera Cluster in Docker Containers.

What does it do

Dockerfile :

1. Build from official docker container
2. Install mariadb-server mariadb-client mariadb-backup and dependencies
3. Copy files (conf/, my.cnf, init.sh)
4. Set /init.sh as entrypoint

init.sh :

1. Modify mysql config file based on environment variables.
2. Check service in the cluster to see if this is a new cluster
3. Install mysql from scratch, if mysql data is not found
4. Updated safe_to_bootstrap to 1 in /var/lib/mysql/grastate.dat, if mysql data is found and this is a new cluster
5. Start mysqld with different arguments.

Docker image

The docker image can be found at https://hub.docker.com/repository/docker/ustcweizhou/mariadb-cluster

Example (DBs use private IP and accessible via nginx)

You can test with command:

docker-compose -f mariadb-cluster-setup.yaml up -d

If it does not work, please download latest docker-compose and try again.

sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose

When all containsers are running, there is a nginx container running with nginx-galera.conf to expose the mariadb cluster.

# docker-compose -f mariadb-cluster-setup.yaml ps
         Name                   Command             State                       Ports
------------------------------------------------------------------------------------------------------
mariadb-cluster_db01_1    /init.sh               Up (healthy)   3306/tcp, 4444/tcp, 4567/tcp, 4568/tcp
mariadb-cluster_db02_1    /init.sh               Up             3306/tcp, 4444/tcp, 4567/tcp, 4568/tcp
mariadb-cluster_db03_1    /init.sh               Up             3306/tcp, 4444/tcp, 4567/tcp, 4568/tcp
mariadb-cluster_dbvip_1   nginx -g daemon off;   Up             0.0.0.0:13306->3306/tcp, 80/tcp

# mysql -h 127.0.0.1 -P13306 -uroot -pcloudstack -e "show status where variable_name in ('wsrep_cluster_status', 'wsrep_incoming_addresses','wsrep_local_state_comment');"
+---------------------------+----------------------------------------+
| Variable_name             | Value                                  |
+---------------------------+----------------------------------------+
| wsrep_local_state_comment | Synced                                 |
| wsrep_incoming_addresses  | 172.16.10.11,172.16.10.12,172.16.10.13 |
| wsrep_cluster_status      | Primary                                |
+---------------------------+----------------------------------------+

Example (DBs use public IPs which are directly accessible)

You can test with command:

docker-compose -f mariadb-cluster-setup-macvlan.yaml up -d

When all containsers are running,

# docker-compose -f mariadb-cluster-setup-macvlan.yaml ps
            Name                Command       State       Ports
---------------------------------------------------------------
docker-mariadb-cluster_db01_1   /init.sh   Up (healthy)        
docker-mariadb-cluster_db02_1   /init.sh   Up (healthy)        
docker-mariadb-cluster_db03_1   /init.sh   Up    

The IPs are accessible, except the container host

# mysql -h 10.0.33.53 -P3306 -uroot -pcloudstack -e "show status where variable_name in ('wsrep_cluster_status', 'wsrep_incoming_addresses','wsrep_local_state_comment');"
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------------------+---------------------------------------------------+
| Variable_name             | Value                                             |
+---------------------------+---------------------------------------------------+
| wsrep_local_state_comment | Synced                                            |
| wsrep_incoming_addresses  | 10.0.33.53:3306,10.0.35.200:3306,10.0.33.212:3306 |
| wsrep_cluster_status      | Primary                                           |
+---------------------------+---------------------------------------------------+

To access the service from the container host,

ip link add host-nic link eth0 type macvlan mode bridge
ip addr add 10.0.33.6/20 dev host-nic (only if the host IP is in different range as container IP)
ip link set host-nic up
ip route add 10.0.33.53/32 dev host-nic

Releases

v1.0        Ubuntu 18.04 and Mariadb 10.4
v1.1        Ubuntu 20.04 and Mariadb 10.5.8
v1.2        Ubuntu 20.04 and Mariadb 10.5.12
v1.3        Ubuntu 22.04 and Mariadb 11.3.2