As of now, I am learning Docker. This reference has mentioned two ways of pulling an image from the Docker registry. Can anyone explain this in simple terms?
Does this mean that we cannot get updates on a pulled image if we use docker image pull command?
They are the same command. From the documentation you linked:
To download a particular image, or set of images (i.e., a repository), use docker image pull (or the docker pull shorthand).
There are many "shortand commands" like:
docker push for docker image push
docker run for docker container run
...
What is the difference between docker pull and docker image pull commands?
None.
Can anyone explain this in simple terms?
They are the same.
Does this mean that we cannot get updates on a pulled image if we use docker image pull command?
No.
Also https://forums.docker.com/t/docker-pull-imagename-vs-docker-image-pull-imagename/59283
Related
I'm learning about Docker Containers, so, I found this repo with a lot of images and references, can anyone help me in order to understand how can I use those images?
I know the docker run --rm command
With docker you first need a docker image. A docker image is a representation of an application that docker can understand and run.
The most common ways to get one is to use docker pull or to generate yours with docker build.
You can check the images you got with docker images
Once you got your image you can run it with docker run MyImage, this will create a container, a container is a running application.
I have a docker image. I want to analyze the docker image history, for this I can use docker image history command in the docker installed environment.
But when am working in a Openshift cluster, I may not have the access to the docker command here. So here I want get the docker history command result for the given image.
So basically I have a docker image and I don't have docker installed there. In this case how can we get the history of that docker image?
Can anyone please help me on this?
You can get the registry info either via curl or skopeo inspect. But the rest of the metadata is stored inside the image itself so you do have to download at least the final layer.
The current process I have for tagging an image in the same registry is below:
docker pull image:1
docker tag image:1 image:2
docker push image:2
Is there a way for this to be done without having to pull down the image before tagging. Would be "seamless" if I was able to refer to an image, tag and push to the reg in less steps.
According a Docker guy in this post from Docker forums, it's not possible. Also:
If the layers already exist and you docker push with a different tag
Docker will figure out there is nothing to push and report Layer
already exists for those layers.
I read the tutorial in this,and it show me can use these commands to pull image to docker registry,like that:
docker pull ubuntu && docker tag ubuntu localhost:5000/batman/ubuntu
docker push localhost:5000/batman/ubuntu
I want to know whether I need to tag already image when I pull image to registry. Is it just only way to pull image to docker registry?
You always need to tag your images first with a tag containing repository information. Then you can push them to your private registry. Please refer also to this blogpost.
The docker repositories contains multiple images. Is it possible to just pull the specific image from Repository.
When I use:
docker pull ubuntu
It pulls down around 8-10 different versions of ubuntu.
If there's a specific image that's tagged, you could use the --tag= (or -t) operator to pull the specific image you're looking for. There's a shorthand form for the command as well, which uses just a colon between the image name and the tag.
So if you want the version of ubuntu that's tagged as quantal, you could use:
docker pull ubuntu:quantal
The longer forms would be:
docker pull --tag="quantal" ubuntu
docker pull --t quantal ubuntu
This will still pull the historical layers used to build the final image, but will be a smaller subset than all of the layers for ubuntu.
[Updated to include Ben's note on shorthand from below. Thanks!]
You can also use
docker pull reponame:tagname
docker pull ubantu:quantal