Where is the Dockerfile when enter docker pull ubuntu in ubuntu docker website

General
1

In https://hub.docker.com/_/ubuntu upper right, it has command

docker pull ubuntu

if paste in terminal, it will pull and create image

docker pull ubuntu
Using default tag: latest
latest: Pulling from library/ubuntu
Digest: sha256:72297848456d5d37d1262630108ab308d3e9ec7ed1c3286a32fe09856619a782
Status: Downloaded newer image for ubuntu:latest
docker.io/library/ubuntu:latest

but where is the Dockerfile as we always see in docker workshop

docker build -t {image_name} .

for the command

docker pull ubuntu
1 Like
2

When using Docker on Linux, you will usually find the files in /var/lib/docker.

3

Or I ask in this way, is image creation must involved Dockerfile?

After I copy the command docker pull ubuntu from webiste
https://hub.docker.com/_/ubuntu
and run the command
docker pull ubuntu

an image is seen in docker desktop. but what happens behind the command
docker pull ubuntu?

Involve download a Dockerfile and docker build?
Then where is the Dockerfile in
https://hub.docker.com/_/ubuntu
?

4

Docker pull won’t build the image but download his layers from the hub.

5

This is for the noble distro which as you can see is built from ‘scratch’ and then from the manifests that correspond to each architecture:

6

As you know, the Dockerfile is the source code from which the image is built. That is not stored on Docker Hub so you don’t get access to that. That is stored in a source code management system somewhere. Docker Hub is an artifact repository. It stores the artifacts from the build which, in the case of Docker, is a container image. The already built image is all you get when you use docker pull <image-name>. No need to build anything because it is the already built layers that get pulled down.