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page_title: Docker Hub Enterprise: Quick-start: Basic Workflow page_description: Brief tutorial on the basics of Docker Hub Enterprise user workflow page_keywords: docker, documentation, about, technology, understanding, enterprise, hub, registry, image, repository

Docker Hub Enterprise Quick Start: Basic User Workflow

Overview

This Quick Start Guide will give you a hands-on look at the basics of using Docker Hub Enterprise (DHE), Docker’s on-premise image storage application. This guide will walk you through using DHE to complete a typical, and critical, part of building a development pipeline: setting up a Jenkins instance. Once you complete the task, you should have a good idea of how DHE works and how it might be useful to you.

Specifically, this guide demonstrates the process of retrieving the official Docker image for Jenkins, customizing it to suit your needs, and then hosting it on your private instance of DHE located inside your enterprise’s firewalled environment. Your developers will then be able to retrieve the custom Jenkins image in order to use it to build CI/CD infrastructure for their projects, no matter the platform they’re working from, be it a laptop, a VM, or a cloud provider.

The guide will walk you through the following steps:

  1. Pulling the official Jenkins image from the public Docker Hub
  2. Customizing the Jenkins image to suit your needs
  3. Pushing the customized image to DHE
  4. Pulling the customized image from DHE
  5. Launching a container from the custom image
  6. Using the new Jenkins container

You should be able to complete this guide in about thirty minutes.

Note: This guide assumes you have installed a working instance of DHE reachable at dhe.yourdomain.com. If you need help installing and configuring DHE, please consult the installation instructions.

Pulling the official Jenkins image

Note: This guide assumes you are familiar with basic Docker concepts such as images, containers, and registries. If you need to learn more about Docker fundamentals, please consult the Docker user guide.

First, you will retrieve a copy of the official Jenkins image from the Docker Hub. By default, if Docker can't find an image locally, it will attempt to pull the image from the Docker Hub. From the CLI of a machine running the Docker Engine on your network, use the docker pull command to pull the public Jenkins image.

$ docker pull jenkins

Note: This guide assumes you can run Docker commands from a machine where you are a member of the docker group, or have root privileges. Otherwise, you may need to add sudo to the example commands below.

Docker will start the process of pulling the image from the Hub. Once it has completed, the Jenkins image should be visible in the output of a docker images command, which lists your available images:

$ docker images
REPOSITORY  TAG     IMAGE ID      CREATED      VIRTUAL SIZE
jenkins     latest  1a7cc22b0ee9  6 days ago   662 MB

Note: Because the pull command did not specify any tags, it will pull the latest version of the public Jenkins image. If your enterprise environment requires you to use a specific version, add the tag for the version you need (e.g., jenkins:1.565).

Customizing the Jenkins image

Now that you have a local copy of the Jenkins image, you’ll customize it so that the containers it builds will integrate with your infrastructure. To do this, you’ll create a custom Docker image that adds a Jenkins plugin that provides fine grained user management. You’ll also configure Jenkins to be more secure by disabling HTTP access and forcing it to use HTTPS. You’ll do this by using a Dockerfile and the docker build command.

Note: These are obviously just a couple of examples of the many ways you can modify and configure Jenkins. Feel free to add or substitute whatever customization is necessary to run Jenkins in your environment.

Creating a build context

In order to add the new plugin and configure HTTPS access to the custom Jenkins image, you need to:

  1. Create text file that defines the new plugin
  2. Create copies of the private key and certificate

All of the above files need to be in the same directory as the Dockerfile you will create in the next step.

  1. Create a build directory called build, and change to that new directory:

    $ mkdir build && cd build

In this directory, create a new file called plugins and add the following line:

role-strategy:2.2.0

(The plugin version used above was the latest version at the time of writing.)

  1. You will also need to make copies of the server’s private key and certificate. Give the copies the following names — https.key and https.pem.

Note: Because creating new keys varies widely by platform and implementation, this guide won’t cover key generation. We assume you have access to existing keys. If you don’t have access, or can’t generate keys yourself, feel free to skip the steps involving them and HTTPS config. The guide will still walk you through building a custom Jenkins image and pushing and pulling that image using DHE.

Creating a Dockerfile

In the same directory as the plugins file and the private key and certificate, create a new Dockerfile with the following contents:

 FROM jenkins

 #New plugins must be placed in the plugins file
 COPY plugins /usr/share/jenkins/plugins

 #The plugins.sh script will install new plugins
 RUN /usr/local/bin/plugins.sh /usr/share/jenkins/plugins

 #Copy private key and cert to image
 COPY https.pem /var/lib/jenkins/cert
 COPY https.key /var/lib/jenkins/pk

 #Configure HTTP off and HTTPS on, using port 1973
ENV JENKINS_OPTS --httpPort=-1 --httpsPort=1973 --httpsCertificate=/var/lib/jenkins/cert --httpsPrivateKey=/var/lib/jenkins/pk

The first COPY instruction in the above will copy the plugin file created earlier into the /usr/share/jenkins directory within the custom image you are defining with the Dockerfile.

The RUN instruction will execute the /usr/local/bin/plugins.sh script with the newly copied plugins file, which will install the listed plugin.

The next two COPY instructions copy the server’s private key and certificate into the required directories within the new image.

The ENV instruction creates an environment variable called JENKINS_OPT in the image you are about to create. This environment variable will be present in any containers launched form the image and contains the required settings to tell Jenkins to disable HTTP and operate over HTTPS.

Note: You can specify any valid port number as part of the JENKINS_OPT environment variable declared above. The value 1973 used in the example is arbitrary.

The Dockerfile, the plugins file, as well as the private key and certificate, must all be in the same directory because the docker build command uses the directory that contains the Dockerfile as its “build context”. Only files contained within that “build context” will be included in the image being built.

Building your custom image

Now that the Dockerfile, the plugins file, and the files required for HTTPS operation are created in your current working directory, you can build your custom image using the docker build command:

docker build -t dhe.yourdomain.com/ci-infrastructure/jnkns-img .

Note: Don’t miss the period (.) at the end of the command above. This tells the docker build command to use the current working directory as the "build context".

This command will build a new Docker image called jnkns-img which is based on the public Jenkins image you pulled earlier, but contains all of your customization.

Please note the use of the -t flag in the docker build command above. The -t flag lets you tag an image so it can be pushed to a custom repository. In the example above, the new image is tagged so it can be pushed to the ci-infrastructure Repository within the dhe.yourdomain.com registry (your local DHE instance). This will be important when you need to push the customized image to DHE later.

A docker images command will now show the custom image alongside the Jenkins image pulled earlier:

$ sudo docker images
REPOSITORY   TAG    IMAGE ID    CREATED    VIRTUAL SIZE
dhe.yourdomain.com/ci-infrastructure/jnkns-img    latest    fc0ab3008d40    2 minutes ago    674.5 MB
jenkins    latest    1a7cc22b0ee9    6 days ago    662 MB

Pushing to Docker Hub Enterprise

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

Failures due to unauthenticated docker push and docker pull commands will look like :

$ docker pull dhe.yourdomain.com/hello-world
Pulling repository dhe.yourdomain.com/hello-world
FATA[0001] Error: image hello-world:latest not found

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

Now that you’ve created the custom image, it can be pushed to DHE using the docker pushcommand:

$ docker push dhe.yourdomain.com/ci-infrastructure/jnkns-img
511136ea3c5a: Image successfully pushed
848d84b4b2ab: Image successfully pushed
71d9d77ae89e: Image already exists
<truncated ouput...>
492ed3875e3e: Image successfully pushed
fc0ab3008d40: Image successfully pushed

You can view the traffic throughput while the custom image is being pushed from the System Health tab in DHE:

DHE console push throughput

Once the image is successfully pushed, it can be downloaded, or pulled, by any Docker host that has access to DHE.

Pulling from Docker Hub Enterprise

To pull the jnkns-img image from DHE, run the docker pull command from any Docker Host that has access to your DHE instance:

$ docker pull dhe.yourdomain.com/ci-infrastructure/jnkns-img
latest: Pulling from dhe.yourdomain.com/ci-infrastructure/jnkns-img
511136ea3c5a: Pull complete
848d84b4b2ab: Pull complete
71d9d77ae89e: Pull complete
<truncated ouput...>
492ed3875e3e: Pull complete
fc0ab3008d40: Pull complete
dhe.yourdomain.com/ci-infrastructure/jnkns-img:latest: The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security.
Status: Downloaded newer image for dhe.yourdomain.com/ci-infrastructure/jnkns-img:latest

You can view the traffic throughput while the custom image is being pulled from the System Health tab in DHE:

DHE console pull throughput

Now that the jnkns-img image has been pulled locally from DHE, you can view it in the output of the docker images command:

 $ docker images
REPOSITORY     TAG    IMAGE ID    CREATED    VIRTUAL SIZE
dhe.yourdomain.com/ci-infrastructure/jnkns-img    latest  fc0ab3008d40    8 minutes ago    674.5 MB

Launching a custom Jenkins container

Now that you’ve successfully pulled the customized Jenkins image from DHE, you can create a container from it with the docker run command:

$ docker run -p 1973:1973 --name jenkins01 dhe.yourdomain.com/ci-infrastructure/jnkns-img
/usr/share/jenkins/ref/init.groovy.d/tcp-slave-angent-port.groovy
 /usr/share/jenkins/ref/init.groovy.d/tcp-slave-angent-port.groovy -> init.groovy.d/tcp-slave-angent-port.groovy
copy init.groovy.d/tcp-slave-angent-port.groovy to JENKINS_HOME
/usr/share/jenkins/ref/plugins/role-strategy.hpi
 /usr/share/jenkins/ref/plugins/role-strategy.hpi -> plugins/role-strategy.hpi
copy plugins/role-strategy.hpi to JENKINS_HOME
/usr/share/jenkins/ref/plugins/dockerhub.hpi
 /usr/share/jenkins/ref/plugins/dockerhub.hpi -> plugins/dockerhub.hpi
copy plugins/dockerhub.hpi to JENKINS_HOME
<truncated output...>
INFO: Jenkins is fully up and running

Note: The docker run command above maps port 1973 in the container through to port 1973 on the host. This is the HTTPS port you specified in the Dockerfile earlier. If you specified a different HTTPS port in your Dockerfile, you will need to substitute this with the correct port numbers for your environment.

You can view the newly launched a container, called jenkins01, using the docker ps command:

$ docker ps
CONTAINER ID     IMAGE     COMMAND     CREATED      STATUS  ...PORTS     NAMES
2e5d2f068504    dhe.yourdomain.com/ci-infrastructure/jnkns-img:latest    "/usr/local/bin/jenk     About a minute ago     Up About a minute     50000/tcp, 0.0.0.0:1973->1973/tcp     jenkins01

Accessing the new Jenkins container

The previous docker run command mapped port 1973 on the container to port 1973 on the Docker host, so the Jenkins Web UI can be accessed at https://<docker-host>:1973 (Don’t forget the s at the end of https.)

Note: If you are using a self-signed certificate, you may get a security warning from your browser telling you that the certificate is self-signed and not trusted. You may wish to add the certificate to the trusted store in order to prevent further warnings in the future.

Jenkins landing page

From within the Jenkins Web UI, navigate to Manage Jenkins (on the left-hand pane) > Manage Plugins > Installed. The Role-based Authorization Strategy plugin should be present with the Uninstall button available to the right.

Jenkins plugin manager

In another browser session, try to access Jenkins via the default HTTP port 8080 — http://<docker-host>:8080. This should result in a “connection timeout,” showing that Jenkins is not available on its default port 8080 over HTTP.

This demonstration shows your Jenkins image has been configured correctly for HTTPS access, your new plugin was added and is ready for use, and HTTP access has been disabled. At this point, any member of your team can use docker pull to access the image from your DHE instance, allowing them to access a configured, secured Jenkins instance that can run on any infrastructure.

Next Steps

For more information on using DHE, take a look at the User's Guide.