Find Repo/Image In Docker - docker

I am trying to pull an image from a Docker registry. I have gone to
http://1.1.1.1/v2/_catalog
And I get a list of all the repos. Then I go to
http://1.1.1.1/v2/repo1/tags/list
And I get a list of all the tags
But what I dont know is when Im trying to pull the image, how do I reference this repo/tag?
I've tried:
docker pull http://1.1.1.1/v2/repo1
docker pull http://1.1.1.1/v2/repo1/tags/latest
I've tried googling it and I just cant find an answer. Im really not sure why. Can anyone assist?

Try this:
docker pull 1.1.1.1/repo1:latest
The command format is:
docker pull <host>:<port>/<repoName>:<repoTag>
If you are pulling image from docker hub, docker client will add the default IP and port of docker hub for you, so you don't need to specific the IP address. But for a private registry, you need to tell docker client where is your image located.

Related

What is the difference between docker pull and docker image pull commands?

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

Docker registry mirror

I'm trying to set a docker mirror to be the default mirror to pull/push images.
As per documentation I already set the file /etc/docker/daemon.json with the following:
{
"registry-mirrors": ["https://localregistry"]
}
Then I try the following:
docker login localregistry
docker pull localregistry/image:tag > it works
docker pull image:tag > doesn't work
I'm always getting "no basic auth credentials error" from the docker daemon, but from the registry log I get err.code="manifest unknown" err.detail="unknown tag"
Any idea?
I'm using docker version 19.03.08
docker login localregistry
First, I hope this is changing the name for the question, because the registry name localregistry will not work...
docker pull localregistry/image:tag > it works
The fact that this works indicates that you likely have a registry name with a . or : in the hostname. Otherwise docker would try to pull localregistry/image:tag from the localregistry user on Docker Hub.
docker pull image:tag > doesn't work
This should always work, failures should be transparent to the user if it's really a mirror of Docker Hub. What happens is it resolves that name to docker.io/library/image:tag, first tries to pull from localregistry/library/image:tag, and any error falls back to a pull from Docker Hub, and any error there finally shows to the user.
Most likely the issue is that you didn't include library as the repo name for your image in the local registry.
If you are using this to include images that don't exist on Docker Hub, then I would skip the mirror and simply refer to the mirror explicitly. Doing otherwise creates many opportunities for nonintuitive failures that aren't easy to see. E.g. a stale image can be pushed to your mirror in place of an upstream image, and Docker will stop pulling updates from upstream. And because any mirror errors fall back to Hub, if you use an image name that you have no control over upstream, someone else could take that name on Hub and begin injecting unknown or even malicious images into your server.
If this doesn't answer your question, then I'd recommend using your question with actual image names and error messages from the logs showing what specifically failed (you can mask out part of the registry name of necessary).

Docker: Push data container onto Docker Hub

I am really new at this Docker stuff, and even newer at Docker Hub, so please bear with me …
I have created a data container to use with my docker image (specifically, a data container to store data for a running mssql-server-lnux image). I know where it is on my local system.
I have a newly created account on Docker Hub and I think I want to push the data container on the hub. I say I think because I’m not sure that it’s the right way to go about it: I want to be able to use the data container from different machines.
If what I have said so far is in the right direction, then how do I push the docker image to the Hub, and how do I then access it later?
You can't push containers, only images, the distinction is important.
Image is akin to a class of your container, and container is essentially an instance of your image.
So if you want to push to share your database then it's not a good idea - you would have to docker commit first and this would get ugly really fast.
But if you just want to start new instances of your mysql on different machines with fresh data containers (there will be no data initially) then go ahead and push the data container image.
Hope this helps.
Okay, here are few steps. Please check if this helps.
Tag your image first. Let's say your image name is 'myapplication' and your docker hub user name is 'dockerhubusername'.
$ docker tag myapplication dockerhubusername/myapplication
Login to docker hub using. Enter user name like 'dockerhubusername' and then password of docker hub account.
$ docker login
Now push command.
$ docker push dockerhubusername/myapplication
Now, login to your docker hub and check if you have image there. Remember, images are pushed to registry/repository like dockerhub not containers.
Assuming you have tagged your image,
Use docker login to configure your docker hub credentials and use docker push to push your image to dockerhub.
$ docker login
$ docker push dockerhub_username/mssql-server-lnux
If you have not yet tagged the image,
$ docker tag mssql-server-lnux dockerhub_username/mssql-server-lnux
To access your image later,
$ docker pull dockerhub_username/mssql-server-lnux
References
Docker Pull
Docker Login

Docker show current registry

In docker, how can one display the current registry info you are currently logged in? I installed docker, if I now do docker push, where does it send my images?
I spend over 30min searching this info from Google and docker docs, and couldn't find it, so I think it deserves its own question.
There's no concept of a "current" registry - full image tags always contain the registry address, but if no registry is specified then the Docker Hub is used as the default.
So docker push user/app pushes to Docker Hub. If you want to push it to a local registry you need to explicitly tag it with the registry address:
docker tag user/app localhost:5000/user/app
docker push localhost:5000/user/app
If your local registry is secured, you need to run docker login localhost:5000 but that does not change the default registry. If you push or pull images without a registry address in the tag, Docker will always use the Hub.
This issue explains the rationale.
The way docker images work is not the most obvious but it is easy to explain.
The location where your images will be sent to must be define in the image name.
When you commit an image you must name it [registry-IP]:[registry-port]/[imagepath]/[image-name]
If you already have the image created and you want to send it to the local registry you must tagged it including the registry path before you push it:
docker tag [image-name] [registry-IP]:[registry-port]/[image-name]
docker push [registry-IP]:[registry-port]/[image-name]

How to pull images to docker registry?

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.

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