Connect to mysql in a docker container from the host

Question

(It's probably a dumb question due to my limited knowledge with Docker or mysql administration, but since I spent a whole evening on this issue, I dare to ask it.)

In a nutshell

I want to run mysql in a docker container and connect to it from my host. So far, the best I have achieved is:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

More details

I'm using the following Dockerfile:

FROM ubuntu:14.04.3
RUN apt-get update && apt-get install -y mysql-server

# Ensure we won't bind to localhost only
RUN grep -v bind-address /etc/mysql/my.cnf > temp.txt \
  && mv temp.txt /etc/mysql/my.cnf

# It doesn't seem needed since I'll use -p, but it can't hurt
EXPOSE 3306

CMD /etc/init.d/mysql start && tail -F /var/log/mysql.log

In the directory where there is this file, I can succesfully build the image and run it with:

> docker build -t my-image .
> docker run -d -p 12345:3306 my-image

When I attach to the image, it seems to work just fine:

# from the host
> docker exec -it <my_image_name> bash

#inside of the container now
$ mysql -u root
Welcome to the MySQL monitor.  Commands end with ; or \g.
[...]

However I don't have that much success from the host:

> mysql -P 12345 -uroot
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Even more details

• I've seen that there's a question which looks like mine. However, it isn't the same (and it doesn't have any answers anyway)
  • I've seen that there are images dedicated to mysql, but I didn't have more success with them
  • My grep -v may feel weird. Admittedly, there may be cleaner way to do it. But when I attach my image, I can observe it actually worked as expected (ie: removed the bind-address). And I can see in the container /var/log/mysql/error.log:

Server hostname (bind-address): '0.0.0.0'; port: 3306 - '0.0.0.0' resolves to '0.0.0.0'; Server socket created on IP: '0.0.0.0'.

Answer 1

If your Docker MySQL host is running correctly you can connect to it from local machine, but you should specify host, port and protocol like this:

mysql -h localhost -P 3306 --protocol=tcp -u root

Change 3306 to port number you have forwarded from Docker container (in your case it will be 12345).

Because you are running MySQL inside Docker container, socket is not available and you need to connect through TCP. Setting "--protocol" in the mysql command will change that.

Answer 2

If you use "127.0.0.1" instead of localhost mysql will use tcp method and you should be able to connect container with:

mysql -h 127.0.0.1 -P 3306 -u root

Answer 3

I recommend checking out docker-compose. Here's how that would work:

Create a file named, docker-compose.yml that looks like this:

version: '2'

services:

  mysql:
    image: mariadb:10.1.19
    ports:
      - 8083:3306
    volumes:
      - ./mysql:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: wp

Next, run:

$ docker-compose up

Notes:

• For latest mariadb image tag see https://hub.docker.com/_/mariadb/

Now, you can access the mysql console thusly:

$ mysql -P 8083 --protocol=tcp -u root -p

Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.5.5-10.1.19-MariaDB-1~jessie mariadb.org binary distribution

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

Notes:

• You can pass the -d flag to run the mysql/mariadb container in detached/background mode.

• The password is "wp" which is defined in the docker-compose.yml file.

• Same advice as maniekq but full example with docker-compose.

Answer 4

The simple method is to share the mysql unix socket to host machine. Then connect through the socket

Steps:

• Create shared folder for host machine eg: mkdir /host
• Run docker container with volume mount option docker run -it -v /host:/shared <mysql image>.
• Then change mysql configuration file /etc/my.cnf and change socket entry in the file to socket=/shared/mysql.sock
• Restart MySQL service service mysql restart in docker
• Finally Connect to MySQL servver from host through the socket mysql -u root --socket=/host/mysql.sock. If password use -p option

Answer 5

if you running docker under docker-machine?

execute to get ip:

docker-machine ip <machine>

returns the ip for the machine and try connect mysql:

mysql -h<docker-machine-ip>

Answer 6

OK. I finally solved this problem. Here follows my solution used in https://sqlflow.org/sqlflow.

The Complete Solution

To make the demo self-contained, I moved all necessary code to https://github.com/wangkuiyi/mysql-server-in-docker.

The Key to the Solution

I don't use the official image on DockerHub.com https://hub.docker.com/r/mysql/mysql-server. Instead, I made my own by installing MySQL on Ubuntu 18.04. This approach gives me the chance to start mysqld and bind it to 0.0.0.0 (all IPs).

For details, please refer to these lines in my GitHub repo.

SQLFLOW_MYSQL_HOST=${SQLFLOW_MYSQL_HOST:-0.0.0.0}

echo "Start mysqld ..."
sed -i "s/.*bind-address.*/bind-address = ${SQLFLOW_MYSQL_HOST}/" \
    /etc/mysql/mysql.conf.d/mysqld.cnf
service mysql start

To Verify My Solution

1. Git clone the aforementioned repo.

   git clone https://github.com/wangkuiyi/mysql-server-in-docker
   cd mysql-server-in-docker
   

2. Build the MySQL server Docker image

   docker build -t mysql:yi .
   

3. Start MySQL server in a container

   docker run --rm -d -p 23306:3306 mysql:yi
   

4. Install the MySQL client on the host, if not yet. I am running Ubuntu 18.04 on the host (my workstation), so I use apt-get.

   sudo apt-get install -y mysql-client
   

5. Connect from the host to the MySQL server running in the container.

   mysql --host 127.0.0.1 --port 23306 --user root -proot
   

Connect from Another Container on the Same Host

We can run MySQL client from even another container (on the same host).

docker run --rm -it --net=host mysql/mysql-server mysql \
   -h 127.0.0.1 -P 13306 -u root -proot

Connect from Another Host

On my iMac, I install the MySQL client using Homebrew.

brew install mysql-client
export PATH="/usr/local/opt/mysql-client/bin:$PATH"

Then, I can access the above Ubuntu host (192.168.1.22).

mysql -h 192.168.1.22 -P 13306 -u root -proot

Connect from a Container Running on Another Host

I can even run MySQL client in a container running on the iMac to connect to the MySQL server in a container on my Ubuntu workstation.

docker run --rm -it --net=host mysql/mysql-server mysql \
    -h 192.168.1.22 -P 13306 -u root -proot

A Special Case

In the case that we run MySQL client and server in separate containers running on the same host -- this could happen when we are setting up a CI, we don't need to build our own MySQL server Docker image. Instead, we can use the --net=container:mysql_server_container_name when we run the client container.

To start the server

docker run --rm -d --name mysql mysql/mysql-server

To start the client

docker run --rm -it --net=container:mysql mysql/mysql-server mysql \
 -h 127.0.0.1 -P 3306 -u root -proot

Answer 7

I do this by running a temporary docker container against my server so I don't have to worry about what is installed on my host. First, I define what I need (which you should modify for your purposes):

export MYSQL_SERVER_CONTAINER=mysql-db
export MYSQL_ROOT_PASSWORD=pswd 
export DB_DOCKER_NETWORK=db-net
export MYSQL_PORT=6604

I always create a new docker network which any other containers will need:

docker network create --driver bridge $DB_DOCKER_NETWORK

Start a mySQL database server:

docker run --detach --name=$MYSQL_SERVER_CONTAINER --net=$DB_DOCKER_NETWORK --env="MYSQL_ROOT_PASSWORD=$MYSQL_ROOT_PASSWORD" -p ${MYSQL_PORT}:3306 mysql

Capture IP address of the new server container

export DBIP="$(docker inspect ${MYSQL_SERVER_CONTAINER} | grep -i 'ipaddress' | grep -oE '((1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.){3}(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])')"

Open a command line interface to the server:

docker run -it -v ${HOST_DATA}:/data --net=$DB_DOCKER_NETWORK --link ${MYSQL_SERVER_CONTAINER}:mysql --rm mysql sh -c "exec mysql -h${DBIP} -uroot -p"

This last container will remove itself when you exit the mySQL interface, while the server will continue running. You can also share a volume between the server and host to make it easier to import data or scripts. Hope this helps!

Answer 8

mysql -u root -P 4406 -h localhost --protocol=tcp -p

Remember to change the user, port and host so that it matches your configurations. The -p flag is required if your database user is configured with a password

Answer 9

In your terminal run: docker exec -it container_name /bin/bash Then: mysql

Answer 10

For conversion，you can create ~/.my.cnf file in host:

[Mysql]
user=root
password=yourpass
host=127.0.0.1
port=3306

Then next time just run mysql for mysql client to open connection.

Answer 11

• docker run -e MYSQL_ROOT_PASSWORD=pass --name sql-db -p 3306:3306 mysql

• docker exec -it sql-db bash

• mysql -u root -p

Answer 12

I was able to connect my sql server5.7 running on my host using the below command : mysql -h 10.10.1.7 -P 3307 --protocol=tcp -u root -p where the ip given is my host ip and 3307 is the port forwaded in mysql docker .After entering the command type the password for myql.that is it.Now you are connected the mysql docker container from the you hostmachine

Answer 13

run following command to run container

docker run --name db_name -e MYSQL_ROOT_PASSWORD=PASS--publish 8306:3306 db_name

run this command to get mysql db in host machine

mysql -h 127.0.0.1 -P 8306 -uroot  -pPASS

in your case it is

mysql -h 127.0.0.1 -P 12345 -uroot  -pPASS

Answer 14

change "localhost" to your real con ip addr
because it's to mysql_connect()