how to start multi instances in one mysql docker container - mysql

Question

I want to deploy data slot to the distributed mysql databases via middleware，need one mysql docker container running two instances with different port, eg. 3306 and 3316.
tried many ways, such as:
Add mysql_3316.sh:
#!/bin/bash
/entrypoint.sh --defaults-file=/etc/mysql/my_3316.cnf
in the rc.local:
#!/bin/sh -e
/usr/local/bin/mysql_3316.sh || exit 1
exit 0
and modified the Dockerfile like below,
RUN touch /etc/mysql/my_3316.cnf
COPY mysql_3316.sh /usr/local/bin/mysql_3316.sh
RUN chmod +x /usr/local/bin/mysql_3316.sh
COPY rc.local /etc/rc.local
RUN chmod +x /etc/rc.local
RUN chown root:root /etc/rc.local
ENTRYPOINT ["docker-entrypoint.sh"]
EXPOSE 3306 3316
CMD ["mysqld"]
it doesn't work while the mysql container comes up, but the 3316 mysql
port instance works by run the /entrypoint.sh --defaults-file=/etc/mysql/my_3316.cnf shell line manually.
tried the init.d ,
RUN touch /etc/mysql/my_3316.cnf
COPY mysql_3316.sh /etc/init.d/mysql_3316
RUN chmod +x /etc/init.d/mysql_3316
RUN update-rc.d mysql_3316 defaults 99
ENTRYPOINT ["docker-entrypoint.sh"]
EXPOSE 3306 3316
CMD ["mysqld"]
doesn't work too.
tried the crontab,
#reboot /usr/local/bin/mysql_3316.sh
#Don't remove the empty line at the end of this file. It is required to run the cron job
and the Dockerfile as that,
COPY mysql_3316.sh /usr/local/bin/mysql_3316.sh
RUN chmod +x /usr/local/bin/mysql_3316.sh
ADD crontab /etc/cron.d/docker-cron
RUN chmod +x /etc/cron.d/docker-cron
RUN crontab /etc/cron.d/docker-cron
ENTRYPOINT ["docker-entrypoint.sh"]
EXPOSE 3306 3316
CMD ["mysqld"]
doesn't work third.
It's been spent much on this key, almost give up...
Any kindly suggestion are welcomed please.
The docker-compose.yml for mysql right here:
services:
mysql:
image: mysql:latest
container_name: mysql
hostname: mysql
restart: unless-stopped
networks:
dockernet:
ipv4_address: 172.18.0.5
ports:
- 3306:3306
- 3316:3316
volumes:
- /Docker/mysql/:/var/lib/mysql/
- ./docker/mysql/mysql/my.cnf:/etc/mysql/my.cnf
- ./docker/mysql/mysql/my_3316.cnf:/etc/mysql/my_3316.cnf
- ./docker/mysql/mysql/logs/:/var/log/mysql/
- ./docker/mysql/mysql/init/:/docker-entrypoint-initdb.d/
entrypoint: ['/entrypoint.sh', '--default-authentication-plugin=mysql_native_password']

Answer 1

Normally you do NOT want to run more than one process in the same container. Despite your title I really think that what you are looking for is to start two containers, both from a MySQL image.
You should not need to change any startup scripts, Dockerfile or anything else to start up similar containers bound to different ports.
Remember that the EXPOSE command only exposes the ports to different containers, not to the outside world.
To access the port you need to use the -p flag with your docker run: https://docs.docker.com/engine/reference/run/#expose-incoming-ports
You can use the same docker image from the same Dockerfile. Just give different -p parameter when you run.
Edit:
You added your docker-compose.yml after my initial response. Using docker-compose will make my advice about -p obsolete, and you should use the ports: section of the docker-compose.yml to vary the port numbers instead.
This answer, however, might not be what you are looking for because based on your comment I think I do not fully understand your use case here.

Answer 2

Use the stock mysql container and just run:
docker run -p3306:3306 --name mysql1 mysql
docker run -p3316:3306 --name mysql2 mysql
# plus appropriate -d -e ... -v ... as needed on both commands
Don't try to build your own image and definitely don't try to run two servers with expected different lifetimes in a single container.