I want to use the docker image of one host in another host (raspi) which is in the same network.
Docker image is there is local repository.
Tried with command like:
docker pull host2IP:PORT/<<Image>>:<<Tag>>
Port I tried : 5000, 3632, 2377, 11000 (referred google to get docker port)
Any leads?
Your command above will not work. You need to push your image to a remote docker registry so it will be available on other hosts to pull from.
You can find instructions on how to setup one in the Official documentation or just create an account in DockerHub to push images in there.
If you don't want to setup a private registry or use DockerHub you can always save a tarball of the image with docker save myimage:mytag > myimage.tar, move the file to the other host, then load it with docker load < myimage.tar
Related
Can docker be connected to more than one registry at a time and how to figure out which registries it is currently connected too?
$ docker help | fgrep registr
login Log in to a Docker registry
logout Log out from a Docker registry
pull Pull an image or a repository from a registry
push Push an image or a repository to a registry
As you can see, there is no option to list the registries. I did find
a way by running:
$ docker system info | fgrep -i registr
Registry: https://index.docker.io/v1/
So... one regsitry at a time only? It is not like apt where one can point to more than one source? Anybody can point me to some good documentation about docker and registries?
Oddly, I search the web to no vail.
Aside from docker login, Docker isn't "connected to a registry" per se. Registry names are part of the image name, and Docker will connect to a registry server if it needs to pull an image.
As a specific example, the official Docker image for Elasticsearch is on a non-default registry run by Elastic. The example in that documentation is
docker pull docker.elastic.co/elasticsearch/elasticsearch:7.17.0
# ^^^^^^^^^^^^^^^^^
# registry host name
You don't need to otherwise configure your system to connect to that registry, download an index, or anything else. In fact, you don't even need this docker pull command; if you directly docker run the image, Docker will download it if it doesn't have a copy locally.
The default registry is Docker Hub, docker.io, and this cannot be changed.
There are several alternate registries out there. The various public-cloud providers each have their own, and there are also several free-standing image registries. Each has its own instructions on how to set it up. You always need to include the registry name as part of the image name. The Google Container Registry has a simple name syntax, for example, so if you use GCR then you can
# build an image locally, labeled to be stored in GCR
# (this step does not contact or use GCR at all)
docker build gcr.io/my-name/my-image:tag
# authenticate to the registry
# (normally GCR has a Google-specific login sequence)
docker login https://gcr.io
# push the image
docker push gcr.io/my-name/my-image:tag
# run the image, pulling it if not present
docker run ... gcr.io/my-name/my-image:tag
I have 2 hosts running the same docker customized image. I have modified the image on host 1 and saved the image to a custom.tar. If I take that image and load it onto host 2 will it just update or should I remove the old docker image first?
There are 2 ways to do that with repository and without repository using load and save.
With repository below are the steps.
Log in on Docker Hub
Click on Create Repository.
Choose a name and a description for your repository and click
Create.
Log into the Docker Hub from the command line
docker login --username=yourhubusername --email=youremail#company.com
tag your image
docker tag <existing-image> <hub-user>/<repo-name>[:<tag>]
Push your image to the repository you created
docker push <hub-user>/<repo-name>:<tag>
Pull the image to host 2
docker pull <hub-user>/<repo-name>:<tag>
This will add the image to docker hub and available on internet and now you can pull this image to any system.
With this approach you can keep the same images with different tags on system. But if you don't need old images better to delete that to avoid junk.
Without docker hub.
This command will create tar bundle.
docker save [OPTIONS] IMAGE [IMAGE...]
example: docker save busybox > busybox.tar
Load an image from a tar archive or STDIN
docker load [OPTIONS]
example:docker load < busybox.tar.gz
Recommended: Docker hub or DTR approach easy to manage unless you have bandwidth issue in case your file is large.
Refer:
Docker Hub Repositories
While trying to build a service on docker-machine i got an error of "image doesn't exist" on that docker-machine manager node. As I checked the docker images command on the manager node, no image was there as expected. But on the root docker side I have those images. I want to access these images on the manager node. I've read few articles where it was mentioned that, maybe I've to upload that image on the docker hub then pull it from that hub. But I want to access it locally. Is there any way to do this as I'm newbie to docker.
This is the command what I tried on my manager machine:
docker#manager:~$ docker service create --name "api-client" -p 4200:4200 api_client
This is my docker images output:
REPOSITORY TAG IMAGE ID CREATED SIZE
api_client latest 097b19c4deb8 27 hours ago 1.15GB
But on my docker#manager terminal, my docker image folder is empty.
The problem is that there is no repository to hold the image. The repository needs to be pulled from to a repository to each node in the Swarm before it can execute. In general you need to do the following:
Setup a repository, if you want a local repository there is a guide here, but it will be some hassle to get it up and running i and "insecure http" version. An easier way is to get yourself a free docker hub account and put your image there.
Tag your local image with the repository name. Howto is shown in the guide above.
docker tag <local image> <repository>/<image:tag>
Login to the repository (if in cloud) and push your image to the repository
docker login
docker push <repository>/<image>:<tag>
To run the image (your command)
docker service create --name "api-client" -p 4200:4200 <repository>/<image>:<tag>
Your can also try to pull an image into the local cache of a node using
docker pull <repository>/<image>:<tag>
Expand RED HAT CONTAINER REGISTRY with a local Docker image repository.
As a Docker user, I can work with the registry (pull, push) everything is OK!
But also, as a user, I can upload an image with the docker hub with the pull command.
For example:
$ docker pull debian
Question:
How to prevent the user to "pull" the image with docker hub and allow using only the openshift internal registry?
Those. Is it possible to configure any config so that the user accesses the internal repository of images?
I have something on my mind that is bugging me. When running docker images I see a list of my local images I have in my docker environment. When pulling Images I pull it from a registry and more specific pull the specified tag managed by the repository.
so there is the registry as the big hub to store all image
repositories
and the repository is storing commits/tagged versions of a specific image
But what is docker images then? It's a registry as well isn't it? It holds all images that I've built locally or pulled.
If my claim is valid:
How does it comply with running a private registry (mentioned here https://docs.docker.com/registry/deploying/)
Running this docker run -d -p 5000:5000 --restart=always --name registry registry:2
Would deploy this new registry into my docker images...
So now I have a registry within my registry... registception?
What is the difference besides the custom registry is deployable?
Its not a local image registry as other questions have pointed. It is an image cache. The purpose of the image cache is to avoid having every time to download the same image whenever you do a docker run.
docker images simply lists all the cached images on the machine. Whenever there is newer image on the registry, the image(some layers) are downloaded and cached when doing docker pull .... Also, when a layer exists in the local cache, docker tells you that, example:
Step 2/2 : CMD /bin/bash
---> Using cache
On the other hand, a docker registry is a central repository to store images. It provide a remote api to pull and push images. The local image cache does not have this feature. Images in the local cache are read and stored used local docker commands that simply read files under /var/lib/docker/...
To make things clear, think of Docker remote registries (such as Docker Hub) as the remote Git repositories. You pull Docker images (like git repositories) that you need and you play with it.
Like remote Git repositories such as GitHub\BitBucket, Docker registries are also public and private. Public registries are for public usage and open-source projects. Examples include in like Docker Hub. Where as private registries are for organizational use or for your own. Examples for private registries include Azure Container Registry, EC2 Container Registry etc.
The official Docker Registry image is just a Docker registry image for your own system, you can't share them with others unless you have a server or a public Internet IP address. Think of it as Bonobo Private Git Server for Windows.
Your local image registry as you mentioned are all those images that you have build locally or pulled from a registry public or private you can see it like a local cache of images that you can re use without download or rebuild each time.
Running the registry what actually does is to spin up a server that implements the Docker Registry API which allows users to push, pull, delete and handles the storage of this images and their layers. See it like a central repository like npm, nexus
For example if you run the registry in your.registry.com:5000
You can do things like
docker build -t your.registry.com:5000/my-image:tag .
docker push your.registry.com:5000/my-image:tag
So others that have access to your server can pull it
docker pull your.registry.com:5000/my-image:tag