logging mysql queries from docker container - mysql

Question

i am new to docker and I am still figuring out how it works. I have setup through docker-compose a wordpress site and the yaml file i am using is the following.
version: '3.3'
services:
db:
image: mysql:5.7
volumes:
- ./db_data/db/backup.sql:/docker-entrypoint-initdb.d/backup.sql #it loads an already existing database
#- ./db_data/all.log:/var/log/mysql/all.log # i want here to have the logs of mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: somewordpress
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
ports:
- "8000:80"
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
volumes:
- ./db_data/wp-content:/var/www/html/wp-content # loads the files from an existing installation of wordpress
volumes:
db_data:
as you can see by this line
- ./db_data/all.log:/var/log/mysql/all.log
i am trying to somehow make it so i can log all the queries made. I have managed to do that by doing the following:
1) docker-compose up, while having commented out the line with all.log from yaml file.
2) logging to the container of the mysql with bash and running the following
mysql -u root -psomewordpress -e "SET global log_output = 'FILE'; SET global general_log_file='/var/log/mysql/all.log'; SET global general_log = 1;"
3) Going to the /var/lib/docker/volumes and getting the file created.
What i am trying to achieve is to make somehow this command part of the yaml file so I can also have the all.log file mounted at the location where the yaml file is.

Answer 1

What I did to solve my problem was using the following:
version: '3.3'
services:
db:
image: mysql:5.7
volumes:
- ./db_data/db/backup.sql:/docker-entrypoint-initdb.d/backup.sql #it loads an already existing database
-./logs/mysql:/var/log/mysql # to get the folder of mysql in my logs/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: somewordpress
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
ports:
- "8000:80"
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
volumes:
- ./db_data/wp-content:/var/www/html/wp-content
This code would sync what is inside the docker container of mysql with my folder logs/mysql. So I put a little shell script in there.
#!/bin/bash
if [ ! -f /var/log/mysql/all.log ]; then
touch /var/log/mysql/all.log
fi
chmod 777 /var/log/mysql/all.log
mysql -u root -psomewordpress -e "SET global log_output = 'FILE'; SET global general_log_file='/var/log/mysql/all.log'; SET global general_log = 1;"
It checks if the all.log file is there, if not it creates it and then starts mysql logging. Thats it, after that all queries are logged directly to all.log in which i have direct access.
One more thing, to execute that shell script you might want to use
docker exec 5.7-mysql "./var/log/mysql/initlogs.sh"
where initlogs.sh is the name of the shell script.
I really hope it would help someone!