# Install MySQL with Docker container

### Start a `mysql` server instance

Starting a MySQL instance is simple:

```console
$ docker run --name some-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag
```

Where `some-mysql` is the name you want to assign to your container, `my-secret-pw` is the password to be set for the MySQL root user and `tag` is the tag specifying the MySQL version you want. 

### Connect to MySQL from the MySQL command line client

The following command starts another `mysql` container instance and runs the `mysql` command line client against your original `mysql` container, allowing you to execute SQL statements against your database instance:

```console
$ docker run -it --network some-network --rm mysql mysql -hsome-mysql -uexample-user -p
```

Where `some-mysql` is the name of your original `mysql` container (connected to the `some-network` Docker network).

This image can also be used as a client for non-Docker or remote instances:

```console
$ docker run -it --rm mysql mysql -hsome.mysql.host -usome-mysql-user -p
```

### Via [`docker-compose`](https://github.com/docker/compose) or [`docker stack deploy`](https://docs.docker.com/engine/reference/commandline/stack_deploy/)

Example `docker-compose.yml` for `mysql`:

```yaml
# Use root/example as user/password credentials
version: '3.1'

services:

  db:
    image: mysql
    # NOTE: use of "mysql_native_password" is not recommended: https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-caching-sha2-password
    # (this is just an example, not intended to be a production configuration)
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: example

  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:808
```

{% hint style="info" %}
[Try in Play With Docker](https://labs.play-with-docker.com/?stack=https://raw.githubusercontent.com/docker-library/docs/06990e05c934d425c74addcc5ea462f53de6c8cd/mysql/stack.yml&_gl=1*1i19ur1*_ga*MTg2OTkyNzQzMi4xNjc2Njk3MjYz*_ga_XJWPQMJYHQ*MTY5MjQyNDQzMC41LjEuMTY5MjQyNTkzMi41OS4wLjA.)
{% endhint %}

Run `docker stack deploy -c stack.yml mysql` (or `docker-compose -f stack.yml up`), wait for it to initialize completely, and visit `http://swarm-ip:8080`, `http://localhost:8080`, or `http://host-ip:8080` (as appropriate).

### Container shell access and viewing MySQL logs

The `docker exec` command allows you to run commands inside a Docker container. The following command line will give you a bash shell inside your `mysql` container:

```console
$ docker exec -it some-mysql bash
```

The log is available through Docker's container log:

```console
$ docker logs some-mysql
```

### Using a custom MySQL configuration file

The default configuration for MySQL can be found in `/etc/mysql/my.cnf`, which may `!includedir` additional directories such as `/etc/mysql/conf.d` or `/etc/mysql/mysql.conf.d`. Please inspect the relevant files and directories within the `mysql` image itself for more details.

If `/my/custom/config-file.cnf` is the path and name of your custom configuration file, you can start your `mysql` container like this (note that only the directory path of the custom config file is used in this command):

```console
$ docker run --name some-mysql -v /my/custom:/etc/mysql/conf.d -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag
```

This will start a new container `some-mysql` where the MySQL instance uses the combined startup settings from `/etc/mysql/my.cnf` and `/etc/mysql/conf.d/config-file.cnf`, with settings from the latter taking precedence.

#### Configuration without a `cnf` file

Many configuration options can be passed as flags to `mysqld`. This will give you the flexibility to customize the container without needing a `cnf` file. For example, if you want to change the default encoding and collation for all tables to use UTF-8 (`utf8mb4`) just run the following:

```console
$ docker run --name some-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
```

If you would like to see a complete list of available options, just run:

```console
$ docker run -it --rm mysql:tag --verbose --help
```

## Reference Links

* <https://hub.docker.com/_/mysql>
* <https://labs.play-with-docker.com/?stack=https://raw.githubusercontent.com/docker-library/docs/06990e05c934d425c74addcc5ea462f53de6c8cd/mysql/stack.yml&_gl=1*1hpfiiv*_ga*MTg2OTkyNzQzMi4xNjc2Njk3MjYz*_ga_XJWPQMJYHQ*MTY5MjQyNDQzMC41LjEuMTY5MjQyNjY2Ny40MC4wLjA.>