We start with this section with a very important tool, Docker Compose, which is used frequently.

Let's start with a case study of why we use Docker Compose.

Case study: How do I deploy a WordPress via a container?

Now pull WordPress locally:

docker pull wordpress

docker image ls
REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
vincent/my-nginx      latest              e3e9c5946773        23 hours ago        109MB
wordpress             latest              a541a1a59631        41 hours ago        447MB
vincent/flask-redis   latest              31b9d9c546b0        3 days ago          919MB
vincent/ubuntu-base   latest              68941b82b183        4 days ago          557MB
ubuntu                16.04               13c9f1285025        2 weeks ago         119MB
redis                 latest              3c41ce05add9        3 weeks ago         95MB
python                2.7                 37093962fbf5        3 weeks ago         914MB
nginx                 latest              719cd2e3ed04        3 weeks ago         109MB
mysql                 latest              c7109f74d339        3 weeks ago         443MB
hello-world           latest              fce289e99eb9        6 months ago        1.84kB

You already have mysql locally, so you don't have to pull it.

Create a mysql container:

We want to set a root password for mysql, how?You can see the mysql Introduction.Use -e MYSQL_ROOT_PASSWORD=123456, and create a database WordPress while starting the container, -e MYSQL_DATABASE=wordpress

Why is the -p parameter not applicable?Because our databases are not accessed by people outside, but by wordpress.So the command is as follows:

docker run -d --name mysql -v mysql-data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 -e MYSQL_DATABASE=wordpress mysql

docker container ls
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                 NAMES
fc99f5a686a1        mysql               "docker-entrypoint.s..."   21 seconds ago      Up 20 seconds       3306/tcp, 33060/tcp   mysql

Version mysql8.0 will encounter the following issues:

 The server requested authentication method unknown to the client
mysqli_real_connect(): The server requested authentication method unknown to the client [caching_sha2_password]
mysqli_real_connect(): (HY000/2054): The server requested authentication method unknown to the client

The solution is:

mysql> ALTER USER root IDENTIFIED WITH mysql_native_password BY 'PASSWORD';
Query OK, 0 rows affected (0.08 sec)

Restart wordpress.

Create a wordpress container:

Configuration parameters for wordpress can also be found in docker hub See above.The commands are as follows:

docker run -d -e WORDPRESS_DB_HOST=mysql:3306 -e WORDPRESS_DB_USER=root -e WORDPRESS_DB_PASSWORD=123456 --link mysql -p 8080:80 wordpress

View containers:

ocker container ls
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
aa6ae7b0795b        wordpress           "docker-entrypoint.s..."   4 seconds ago       Up 3 seconds        0.0.0.0:8080->80/tcp   jolly_zhukovsky
fc99f5a686a1        mysql               "docker-entrypoint.s..."   4 minutes ago       Up 4 minutes        3306/tcp, 33060/tcp    mysql

Then visit 127.0.0.1:8080 and the following page appears:

Indicates that the installation was successful.