我如何知道我的 docker mysql 容器何时启动并且 mysql 已准备好接受查询? [英] How do I know when my docker mysql container is up and mysql is ready for taking queries?

问题描述

我正在部署几个不同的 docker 容器，mysql 是第一个.我想在数据库启动后立即运行脚本并继续构建其他容器.该脚本一直失败，因为它试图在设置 mysql 的入口点脚本时运行(来自 这个官方的 mysql 容器)，仍在运行.

I am deploying a few different docker containers, mysql being the first one. I want to run scripts as soon as database is up and proceed to building other containers. The script has been failing because it was trying to run when the entrypoint script, which sets up mysql (from this official mysql container), was still running.

sudo docker run --name mysql -e MYSQL_ROOT_PASSWORD=MY_ROOT_PASS -p 3306:3306 -d mysql
[..] wait for mysql to be ready [..]
mysql -h 127.0.0.1 -P 3306 -u root --password=MY_ROOT_PASS < MY_SQL_SCRIPT.sql

有没有办法等待一个入口点 mysql 安装脚本在 docker 容器内完成的信号?Bash sleep 似乎不是最佳解决方案.

Is there a way to wait for a signal of an entrypoiny mysql setup script finishing inside the docker container? Bash sleep seems like a suboptimal solution.

去寻找这样的 bash 脚本.不是最优雅和最蛮力的，但就像魅力一样.也许有人会觉得这很有用.

Went for a bash script like this. Not the most elegant and kinda brute force but works like a charm. Maybe someone will find that useful.

OUTPUT="Can't connect"
while [[ $OUTPUT == *"Can't connect"* ]]
do
    OUTPUT=$(mysql -h $APP_IP -P :$APP_PORT -u yyy --password=xxx <       ./my_script.sql 2>&1)
done

推荐答案

您可以安装 mysql-client 包并使用 mysqladmin 来 ping 目标服务器.在使用多个 docker 容器时很有用.结合 sleep 并创建一个简单的等待循环:

You can install mysql-client package and use mysqladmin to ping target server. Useful when working with multiple docker container. Combine with sleep and create a simple wait-loop:

while ! mysqladmin ping -h"$DB_HOST" --silent; do
    sleep 1
done

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