Mysql 在将 /var/lib/mysql 挂载到本地主机卷时不会在 docker 容器中启动

Question

我有以下Dockerfile来创建运行NGINX和MYSQL的容器。我正在尝试将/var/lib/mysql 挂载到本地 Docker 主机，以便在容器被销毁后保留 MySQL 数据库。

FROM ubuntu:16.04
MAINTAINER - ******

## Install php nginx mysql supervisor ###
########################################
RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y 
php-fpm 
php-cli 
php-gd  
php-mcrypt 
php-mysql 
php-curl 
php-xml 
php-json 
nginx 
curl 
unzip 
mysql-server 
supervisor

### Nginx  & PHP-FPM ###
########################

# Remove the default Nginx configuration file
RUN rm -v /etc/nginx/nginx.conf
# Copy configuration files from the current directory
ADD files/nginx.conf /etc/nginx/nginx.conf
ADD files/php-fpm.conf /etc/php/7.0/fpm/

### MYSQL ###
############
ENV ROOT_PWD test
### Supervisor.conf ###
######################
ADD files/supervisord.conf /etc/supervisor/supervisord.conf

### Container configuration ###
###############################
EXPOSE 80
VOLUME /DATA
VOLUME /var/lib/mysql
# Set the default command to execute
# when creating a new container
ADD start.sh /
RUN chmod u+x /start.sh
CMD /start.sh

以下是我的入口点脚本 start.sh：

#!/bin/sh

# 1.MYSQL SETUP 
#
# ###########
MYSQL_CHARSET=${MYSQL_CHARSET:-"utf8"}
MYSQL_COLLATION=${MYSQL_COLLATION:-"utf8_unicode_ci"}
create_data_dir() {
mkdir -p /var/lib/mysql
chmod -R 0700 /var/lib/mysql
chown -R mysql:mysql /var/lib/mysql
}
create_run_dir() {
mkdir -p /run/mysqld
chmod -R 0755 /run/mysqld
chown -R mysql:root /run/mysqld
}
create_log_dir() {
mkdir -p /var/log/mysql
chmod -R 0755 /var/log/mysql
chown -R mysql:mysql /var/log/mysql
}
mysql_default_install() {
/usr/bin/mysql_install_db --datadir=/var/lib/mysql
}
create_modx_database() {
# start mysql server.
/usr/bin/mysqld_safe >/dev/null 2>&1 &
# wait for mysql server to start (max 30 seconds).
timeout=30
echo -n "Waiting for database server to accept connections"
while ! /usr/bin/mysqladmin -u root status >/dev/null 2>&1
do
timeout=$(($timeout - 1))
if [ $timeout -eq 0 ]; then
echo -e "nCould not connect to database server. Aborting..."
exit 1
fi
echo -n "."
sleep 1
done
echo
# create database and assign user permissions.
if [ -n "${DB_NAME}" -a -n "${DB_USER}" -a -n "${DB_PASS}" ]; then
echo "Creating database "${DB_NAME}" and granting access to "${DB_USER}" database."
mysql -uroot  -e  "CREATE DATABASE ${DB_NAME};"
mysql -uroot  -e  "GRANT USAGE ON *.* TO ${DB_USER}@localhost IDENTIFIED BY '${DB_PASS}';"
mysql -uroot  -e  "GRANT ALL PRIVILEGES ON ${DB_NAME}.* TO ${DB_USER}@localhost;"
fi 
}
set_mysql_root_pw() {
# set root password for mysql.
echo "Setting root password"
/usr/bin/mysqladmin -u root password "${ROOT_PWD}"
# shutdown mysql reeady for supervisor to start mysql.
/usr/bin/mysqladmin -u root --password=${ROOT_PWD} shutdown
}

# 2.NGINX & PHP-FPM 
#
# ################
create_www_dir() {
# Create LOG directoties for NGINX & PHP-FPM
echo "Creating www directories"
mkdir -p /DATA/logs/php-fpm
mkdir -p /DATA/logs/nginx
mkdir -p /DATA/www
}
apply_www_permissions(){
echo "Applying www permissions"
chown -R www-data:www-data /DATA/www /DATA/logs
}

# Running all script functions
create_data_dir
create_run_dir
create_log_dir
mysql_default_install
create_modx_database
set_mysql_root_pw
create_www_dir
apply_www_permissions
# Start Supervisor 
echo "Starting Supervisor"
/usr/bin/supervisord -n -c /etc/supervisor/supervisord.conf

我可以使用以下方法成功运行容器，而无需将/var/lib/mysql 文件夹挂载到本地 docker 主机：

docker run  --name modx.test --expose 80  -d -e 'VIRTUAL_HOST=modx.test' -e 'DB_NAME=modx' -e 'DB_USER=modx' -e 'DB_PASS=test' -v /data/sites/test:/DATA  modx

如果我尝试使用以下方法挂载/var/lib/mysql：

docker run  --name modx.test --expose 80  -d -e 'VIRTUAL_HOST=modx.test' -e 'DB_NAME=modx' -e 'DB_USER=modx' -e 'DB_PASS=test' -v /data/sites/test:/DATA  -v /data/sites/test/mysql:/var/lib/mysql modx

发生以下错误：2017-08-24 07:47:22 [ERROR] The data directory '/var/lib/mysql' already exist and is not empty. Waiting for database server to accept connections.............................-e Could not connect to database server. Aborting...

Answer 1

设法解决了问题。通过使用/usr/sbin/mysqld --initialize-insecure --datadir=/var/lib/mysql，还添加一个 IF 子句来检查是否已创建初始数据库。

mysql_default_install() {
if [ ! -d "/var/lib/mysql/mysql" ]; then
echo "Creating the default database"
/usr/sbin/mysqld --initialize-insecure --datadir=/var/lib/mysql
else
echo "MySQL database already initialiazed"
fi
}