DO188 - ch03s02

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Guided Exercise: Container Image Registries

Interact with container images in multiple container registries.

Outcomes

You should be able to:

Log in to container image registries.
Move container images between registries.
Test Quay images.

As the student user on the workstation machine, use the lab command to prepare your system for this exercise.

[student@workstation ~]$ lab start images-basics

Instructions

In this exercise, your team must ensure that the internal Dev and Test pipelines use the same Python container image as the one that is in Red Hat OpenShift Container Platform (RHOCP).

To do so, copy the Python image from the RHOCP registry to the internal registry:

Source: default-route-openshift-image-registry.apps.ocp4.example.com/default/python:3.9-ubi8
Destination: registry.ocp4.example.com:8443/developer/python:3.9-ubi8

[student@workstation ~]$ oc login -u admin -p redhatocp \
    https://api.ocp4.example.com:6443
Login successful.
...output omitted...

Note

RHOCP and the oc command are explored later in the course.

[student@workstation ~]$ podman login -u $(oc whoami) -p $(oc whoami -t) \
  default-route-openshift-image-registry.apps.ocp4.example.com
Login Succeeded!

[student@workstation ~]$ podman login -u developer -p developer \
  registry.ocp4.example.com:8443
Login Succeeded!

Use skopeo to copy the default-route-openshift-image-registry.apps.ocp4.example.com/default/python:3.9-ubi8 image to the registry.ocp4.example.com:8443 registry.

[student@workstation ~]$ \
  RHOCP_REGISTRY="default-route-openshift-image-registry.apps.ocp4.example.com"
[student@workstation ~]$ skopeo copy --dest-tls-verify=false \
  docker://${RHOCP_REGISTRY}/default/python:3.9-ubi8 \
  docker://registry.ocp4.example.com:8443/developer/python:3.9-ubi8
Getting image source signatures
...output omitted...

Make the image public in the internal registry.
1. In a web browser, navigate to https://registry.ocp4.example.com:8443 and log in with the user developer and password developer.
2. Type developer in the Filter Repositories field, then click the developer/python repository.
3. Click the Settings icon at the bottom of the page. Scroll to the Repository Visibility settings and click Make Public. Then, click OK.

Test the image as an unauthenticated user.

In a terminal, log out from all container image registeries.

[student@workstation ~]$ podman logout --all
Removed login credentials for all registries

Pull the registry.ocp4.example.com:8443/developer/python:3.9-ubi8 image.

[student@workstation ~]$ podman pull \
  registry.ocp4.example.com:8443/developer/python:3.9-ubi8
Trying to pull registry.ocp4.example.com:8443/developer/python:3.9-ubi8...
...output omitted...
e972...ac821

Start a container that uses the image.

[student@workstation ~]$ podman run --rm \
  registry.ocp4.example.com:8443/developer/python:3.9-ubi8 python3 --version
Python 3.9.13

Finish

On the workstation machine, use the lab command to complete this exercise. This is important to ensure that resources from previous exercises do not impact upcoming exercises.

[student@workstation ~]$ lab finish images-basics

Discuss Red Hat OpenShift Development I: Introduction to Containers with Podman

Go to community

Red Hat OpenShift Development I: Introduction to Containers with Podman (DO188)

Haley_Ruccio

26 lip 2023

A developer introduction to building and managing containers with Podman for deploying applications on Red Hat OpenShift Container Platform.Red Hat OpenShift Development I: Introduction to Containers with Podman (DO188) introduces students to building, running, and managing containers with Podman and Red Hat OpenShift. This course helps students build the core skills for developing containerized applications through hands-on experience. These skills can be applied using all versions of OpenShift, including Red Hat OpenShift on AWS (ROSA), Azure Red Hat OpenShift, and OpenShift Container Platform.This course is based on Red Hat® Enterprise Linux® 8, Podman 4.2 and Red Hat OpenShift® 4.12.Course content summaryIntroduction to containersRun containers with Podman CLI and Podman DesktopBuild custom container imagesManage container imagesRemote debugging with containersBasic container networkingPersist data with containersRun multi-container applicationsTroubleshoot Container DeploymentsOrchestrate containers with OpenShift and KubernetesAudience for this courseDevelopers and Site Reliability Engineers that are new to container technology.System administrators and platform operators who are interested in managing OpenShift clusters and containerized applications should enroll in Red Hat OpenShift Administration I: Containers & Kubernetes (DO180).Prerequisites for this courseTake our free assessment to gauge whether this offering is the best fit for your skills.Some experience with web application architectures and their corresponding technologies.Experience in the use of a Linux terminal session, issuing operating system commands, and familiarity with shell scripting is recommended.Technology considerationsRequires internet connection.

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Welcome to the Red Hat OpenShift Development: Intro to containers with Podman (DO188) group!

cschunke

18 lip 2023

We are excited to launch a space dedicated to the Red Hat Training courseRed Hat OpenShift Development I: Introduction to Containers with Podman! To gain the most value from this group - click the "Join Group" button in the upper right hand corner.We encourage group members to collaborate in this group to discuss topics, ask questions, share best practices and tips, provide course feedback, and share their accomplishments as it relates to DO188.Read more about Red Hat OpenShift Development: Intro to containers with Podman here.

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Revision: do188-4.14-8c43a16