warpcomdev/iotp-xtradb repository overview

⁠iotp-xtradb

This image deploys an instance of percona-xtradb-cluster, version 5.7.

⁠Configuration

⁠Volumes

• Database files are stored in volume /var/lib/mysql
• Additional configuration files can be stored in /etc/my.cnf.d

⁠Ports

TCP Ports used by this image:

• 3306: Mysql.
• 4567: Percona group communication.
• 4444: SST (State Snapshot Transfer).
• 4568: Incremental SST.

⁠Environment:

• MYSQL_NODE_ID: 1, 2, 3... (default 1).
• MYSQL_DATADIR: Path to the data folder (default /var/lib/mysql).
• MYSQL_CLUSTER_ADDRESS: Cluster addresses list for percona xtradb (e.g.: server1,server2,server3).
• MYSQL_CLUSTER_NAME: Cluster name (default pxc-cluster).
• MYSQL_STRICT_MODE: Percona strict mode (default ENFORCING).
• MYSQL_PASSWORD: Initial mysql root password (default changeme).
• MYSQL_SST_PASSWORD: Initial password for SST (default changeme).
• MYSQL_EXPORTER_PASSWORD: Initial password for prometheus exporter (default changeme).

⁠Logging

Error logging is performed to stdout. Query log is not enabled.

⁠Additional mysql config

mysqld will read any configuration file with a .cnf extension mounted to the /etc/my.cnf.d folder.

Optionally, you can name the file with a .cnf.template extension. In that case, the entrypoint will replace in the file any reference to an environment variable, with the actual value of the variable, before loading the configuration.

For instance, if you want to create a "slow query log" file named after the mysql node id, you can mount the following file as /etc/my.cnf.d/slow_query_log.cnf.template:

[mysqld]
slow_query_log = /var/log/slow_queries_node_${MYSQL_NODE_ID}

⁠Initialization

If MYSQL_NODE_ID is 1 and $MYSQL_DATADIR (default /var/lib/mysql) is empty (i.e. missing the mysqlsubfolder, on first deployment of the first container in the statefulset), the entrypoint will create an empty database and set the proper root and sstuser passwords.

In any other case, the entrypoint will not attempt to init the database, in order to avoid possible information loss.

⁠Backup

This image includes the most recent version of minio client⁠ at the time of build. mc is installed in /usr/bin and can be used to stream mysql dumps straight into minio backend storage.