Docker mysql ERROR 1396 (HY000): Operation CREATE USER failed for 'root'@'%'

Question

I am trying to set up two containers one running Python, and the other mysql. This is my docker-compose.yml file:

version: '3' services:     python:         restart: always         build: ./budget/dockerfiles/python/         ports:             - "5000:5000"         links:             - db         depends_on:             - db         volumes:             - ./budget/:/app:z         entrypoint:             - python             - -u             - /app/run.py      db:         build: ./budget/dockerfiles/mysql/         environment:             MYSQL_ROOT_PASSWORD: password             MYSQL_DATABASE: database-name             MYSQL_USER: root             MYSQL_PASSWORD: password         volumes:             - ./Dump.sql:/db/Dump.sql:z             - ./Dump_Test.sql:/db/Dump_Test.sql:z             - ./big_fc.sql:/db/big_fc.sql:z         ports:             - "3306:3306" 

However, when I run docker-compose up -d --build, the containers are built, but the mysql container crashes. In the log, it says:

ERROR 1396 (HY000): Operation CREATE USER failed for 'root'@'%'  

I wanted to try what this post suggests, but I cannot even enter the container since it is crashed. Can somebody tell me what I can do?

Answer 1

According to this github issue, the problem is setting MYSQL_USER to root. It will fail to create the second user 'root'@'%' since it will already exist in the users table.

Therefore, this can be solved by only setting MYSQL_ROOT_PASSWORD, MYSQL_DATABASE, and MYSQL_PASSWORD in the docker-compose.yml file.