Understanding Docker Container Wait Command

The docker container wait command is designed to halt execution until one or more specified containers have stopped, and it then prints their exit codes. This can be particularly useful when you need to synchronize processes or scripts that depend on the completion of certain containerized tasks.

Syntax

docker container wait CONTAINER [CONTAINER...]

Example: Waiting for a Single Container to Exit

Let's consider a scenario where you have a container named web_server running a web application. You want to wait until this container exits and retrieve its exit code. Here's how you can achieve that:

docker wait web_server

In this example, the docker wait command will block until the web_server container stops, and then it will print the exit code of that container.

Example: Waiting for Multiple Containers

The docker container wait command is not limited to a single container; you can wait for the exit of multiple containers simultaneously. For instance:

docker wait container1 container2

This command will block until both container1 and container2 have exited, and it will display their respective exit codes.

Interacting with the Wait Command in Real Time

In a separate terminal, you can simulate the stopping of a container to observe the behavior of the docker wait command. Suppose you want to stop the web_server container:

docker stop web_server

Upon executing the docker stop command, the original terminal where docker wait web_server was running will display the exit code of the stopped container.

In summary, the docker container wait command provides a simple yet effective means of synchronizing your Docker workflows, allowing you to wait for the completion of specific containers and gather information about their exit status. Incorporating this command into your Docker scripts can enhance the overall control and coordination of containerized processes.