5.9 KiB

Raw Blame History

+++ title = "User guide" description = "Documentation describing basic use of Docker Trusted Registry" keywords = ["docker, documentation, about, technology, hub, enterprise"] [menu.main] parent="smn_dhe" weight=3 +++

Docker Trusted Registry User's Guide

This guide covers tasks and functions a user of Docker Trusted Registry will need to know about, such as pushing or pulling images, etc. For tasks Docker Trusted Registry administrators need to accomplish, such as configuring or monitoring Docker Trusted Registry, please visit the Administrator's Guide.

Overview

The primary use case for Docker Trusted Registry users is to push and pull images to and from the Docker Trusted Registry image storage service. For example, you might pull an Official Image for Ubuntu from the Docker Hub, customize it with configuration settings for your infrastructure and then push it to your Docker Trusted Registry image storage for other developers to pull and use for their development environments.

Pushing and pulling images with Docker Trusted Registry works very much like any other Docker registry: you use the docker pull command to retrieve images and the docker push command to add an image to a Docker Trusted Registry repository. To learn more about Docker images, see User Guide: Working with Docker Images. For a step-by-step example of the entire process, see the Quick Start: Basic Workflow Guide.

Note: If your Docker Trusted Registry instance has authentication enabled, you will need to use your command line to docker login <dtr-hostname> (e.g., docker login dtr.yourdomain.com).

Failures due to unauthenticated docker push and docker pull commands will look like :
$ docker pull dtr.yourdomain.com/hello-world
Pulling repository dtr.yourdomain.com/hello-world
FATA[0001] Error: image hello-world:latest not found

$ docker push dtr.yourdomain.com/hello-world
The push refers to a repository [dtr.yourdomain.com/hello-world] (len: 1)
e45a5af57b00: Image push failed
FATA[0001] Error pushing to registry: token auth attempt for registry
https://dtr.yourdomain.com/v2/:
https://dtr.yourdomain.com/auth/v2/token/?scope=
repository%3Ahello-world%3Apull%2Cpush&service=dtr.yourdomain.com
request failed with status: 401 Unauthorized

Pushing Images

You push an image up to a Docker Trusted Registry repository by using the docker push command.

You can add a tag to your image so that you can more easily identify it amongst other variants and so that it refers to your Docker Trusted Registry server.

$ docker tag hello-world:latest dtr.yourdomain.com/yourusername/hello-mine:latest

The command labels a hello-world:latest image using a new tag in the [REGISTRYHOST/][USERNAME/]NAME[:TAG] format. The REGISTRYHOST in this case is your Docker Trusted Registry server, dtr.yourdomain.com, and the USERNAME is yourusername. Lastly, the image tag is set to hello-mine:latest.

Once an image is tagged, you can push it to Docker Trusted Registry with:

$ docker push dtr.yourdomain.com/yourusername/hello-mine:latest

Note: If the Docker daemon on which you are running docker push doesn't have the right certificates set up, you will get an error similar to:

$ docker push dtr.yourdomain.com/demouser/hello-world
FATA[0000] Error response from daemon: v1 ping attempt failed with error:
Get https://dtr.yourdomain.com/v1/_ping: x509: certificate signed by
unknown authority. If this private registry supports only HTTP or HTTPS
with an unknown CA certificate, please add `--insecure-registry
dtr.yourdomain.com` to the daemon's arguments. In the case of HTTPS, if
you have access to the registry's CA certificate, no need for the flag;
simply place the CA certificate at
/etc/docker/certs.d/dtr.yourdomain.com/ca.crt

Pulling images

You can retrieve an image with the docker pull command, or you can retrieve an image and run Docker to build the container with the docker runcommand.

To retrieve an image from Docker Trusted Registry and then run Docker to build the container, add the needed info to docker run:

    $ docker run dtr.yourdomain.com/yourusername/hello-mine
    latest: Pulling from dtr.yourdomain.com/yourusername/hello-mine
    511136ea3c5a: Pull complete
    31cbccb51277: Pull complete
    e45a5af57b00: Already exists
    Digest: sha256:45f0de377f861694517a1440c74aa32eecc3295ea803261d62f950b1b757bed1
    Status: Downloaded newer image for dtr.yourdomain.com/demouser/hello-mine:latest

Note that if you don't specify a version, by default the latest version of an image will be pulled.

If you run docker images after this you'll see a hello-mine image.

    $ docker images
    REPOSITORY                           TAG     IMAGE ID      CREATED       VIRTUAL SIZE
    dtr.yourdomain.com/yourusername/hello-mine  latest  e45a5af57b00  3 months ago  910 B

To pull an image without building the container, use docker pull and specify your Docker Trusted Registry by adding it to the command:

 $ docker pull dtr.yourdomain.com/yourusername/hello-mine

Next Steps

For information on administering Docker Trusted Registry, take a look at the Administrator's Guide.