Docker container connection implementation steps analysis

Generally speaking, after the container is started, we use the services provided by the container through port mapping. In fact, port mapping is only one way to use container services. In addition to this method, you can also use container connection to use container services.

For example, there are two containers, one container runs a SpringBoot project, and the other container runs a MySQL database. SpringBoot can directly access the MySQL database through the container connection without having to access the MySQL service through port mapping.

To keep the case simple, let me give you another example:

There are two containers, one nginx container and the other ubuntu. I start the nginx container, but do not assign port mappings, then start ubuntu, connect through the container, and access nginx in ubuntu.

The specific steps are as follows:

First, start an nginx container, but do not assign a port. The command is as follows:

docker run -d --name nginx1 nginx

The command execution results are as follows:

After the container is started successfully, it is inaccessible in the host machine.

Start Ubuntu

Next, start an ubuntu and establish a connection with nginx as follows:

docker run -dit --name ubuntu --link nginx1:mylink ubuntu bash

Here, --link is used to establish a connection. nginx1 is the container to which the connection is to be established, and the following mylink is the alias of the connection.

After successful operation, enter the ubuntu command line:

docker exec -it ubuntu bash

Then, there are two ways to view nginx information:

The first

Enter env directly in the Ubuntu console to view the environment variable information:

You can see that Docker creates a series of environment variables for nginx. Each variable is prefixed with MYLINK, which is the alias we just gave to the connection. Developers can use these environment variables to configure their applications to connect to nginx. The connection is secure and private. The access results are as follows:

The second

Another way is to view the hosts file of Ubuntu, as follows:

As you can see, several aliases have been given to nginx1 in the hosts file of Ubuntu. You can directly use these aliases to access nginx1.

Tips:

By default, the curl command is not installed in the Ubuntu container. You need to install it manually. The installation command is as follows:

apt-get update
apt-get install curl

The above is the full content of this article. I hope it will be helpful for everyone’s study. I also hope that everyone will support 123WORDPRESS.COM.