分析Macosx下使用docker/mysql的问题

问题描述

在macosx下如果指定本地目录替换/var/lib/mysql，运行时会出现文件权限的错误，导致mysqld无法正常运行

Creating mysql_test-mysql_1
Attaching to mysql_test-mysql_1
test-mysql_1 | Initializing database
test-mysql_1 | 2016-03-23T04:32:37.437789Z 0 [Warning] Setting lower_case_table_names=2 because file system for /var/lib/mysql/ is case insensitive
test-mysql_1 | 2016-03-23T04:32:37.466955Z 0 [ERROR] InnoDB: Operating system error number 13 in a file operation.
test-mysql_1 | 2016-03-23T04:32:37.467828Z 0 [ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.
test-mysql_1 | 2016-03-23T04:32:37.468824Z 0 [ERROR] InnoDB: Operating system error number 13 in a file operation.
test-mysql_1 | 2016-03-23T04:32:37.468912Z 0 [ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.
test-mysql_1 | 2016-03-23T04:32:37.470280Z 0 [ERROR] InnoDB: Cannot open datafile './ibdata1'
test-mysql_1 | 2016-03-23T04:32:37.470309Z 0 [ERROR] InnoDB: Could not open or create the system tablespace. If you tried to add new data files to the system tablespace, and it failed here, you should now edit innodb_data_file_path in my.cnf back to what it was, and remove the new ibdata files InnoDB created in this failed attempt. InnoDB only wrote those files full of zeros, but did not yet use them in any way. But be careful: do not remove old data files which contain your precious data!
test-mysql_1 | 2016-03-23T04:32:37.470317Z 0 [ERROR] InnoDB: InnoDB Database creation was aborted with error Cannot open a file. You may need to delete the ibdata1 file before trying to start up again.
test-mysql_1 | 2016-03-23T04:32:38.073222Z 0 [ERROR] Plugin 'InnoDB' init function returned error.
test-mysql_1 | 2016-03-23T04:32:38.073268Z 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
test-mysql_1 | 2016-03-23T04:32:38.073283Z 0 [ERROR] Failed to initialize plugins.
test-mysql_1 | 2016-03-23T04:32:38.073289Z 0 [ERROR] Aborting
test-mysql_1 | 
mysql_test-mysql_1 exited with code 1

解决方案

• 创建在scripts目录下mysqld启动脚本

#!/bin/bash
# From https://github.com/docker-library/mysql/issues/99
set -e # fail on any error

echo '* Working around permission errors in Docker on Mac locally by making sure that "mysql" uses the same uid and gid as the host volume'
TARGET_UID=$(stat -c "%u" /var/lib/mysql)
echo '-- Setting mysql user to use uid '$TARGET_UID
usermod -o -u $TARGET_UID mysql || true
TARGET_GID=$(stat -c "%g" /var/lib/mysql)
echo '-- Setting mysql group to use gid '$TARGET_GID
groupmod -o -g $TARGET_GID mysql || true
echo
echo '* Starting MySQL'
chown -R mysql:root /var/run/mysqld/
/entrypoint.sh mysqld --user=mysql --console

• 创建docker-compose.py，指定run-mysqld.sh脚本为容器入口

test-mysql:
    image: mysql 
    ports:
        - "3306:3306"
    volumes:   
        - /localhost/mysql/data:/var/lib/mysql 
        - ./scripts/run-mysqld.sh:/run-mysqld.sh
    environment:
        - MYSQL_DATABASE=play
        - MYSQL_USER=play
        - MYSQL_PASSWORD=play
        - MYSQL_ROOT_PASSWORD=123456
    entrypoint: /run-mysqld.sh

• 运行docker-compose up命令，启动容器