Start Multiple Docker Containers¶
In this lecture we're running two containers side-by-side.
Running multiple docker containers from the command line step by step¶
This shows the difference between containers and images. We will create two containers (linux1, linux2) based on the same image (ubuntu)
docker run -it -d --rm --name linux1 ubuntu /bin/bash
- creates container named "linux1"
- additional flags:
-dstarts the container as "detached". Use "docker attach" to attach to it later on.
--rmcleans up the container after stopping. The container will be removed, basically the same as "docker rm container_identifier" after stopping the container. So everything is kept tidy.
--namewill give the container a dedicated name, which makes it easier to address the container later on.
Next we'll start the second container:
docker run -it -d --rm --name linux2 ubuntu /bin/bash
👆🏻 This creates container "linux2"
docker attach linux1
This 👆🏻 attaches to container linux1
This lists the file system on linux1
Creates a new directory on container linux1
Shows that "mylinux1" was created
docker attach linux2
Attaches to container linux2
This one does a few things: - Shows that the directory of linux2 is different than linux1, although they are both from the same image "ubuntu" - They are separated, they don't share their file-system - The bash process is isolated in the container
This will exit the bash and also remove the container because of the --rm command
docker ps -a
Shows only one container which is running, the other one got removed
Exits the only running container linux1 and deletes the container
On any CLI enter
docker ps -a
That should show you nothing anymore. Perfect, cleanup is done, let's continue!