In this episode, hosts Lois Houston and Nikita Abraham, along with senior OCI instructor Mahendra Mehra, discuss how Oracle Cloud Infrastructure Registry simplifies the development-to-production workflow for developers.
Listen to Mahendra explain important container registry concepts, such as images, repositories, image tags, and image paths, as well as how they relate to each other.
OCI Container Engine for Kubernetes Specialist: https://mylearn.oracle.com/ou/course/oci-container-engine-for-kubernetes-specialist/134971/210836
Oracle University Learning Community: https://education.oracle.com/ou-community
X (formerly Twitter): https://twitter.com/Oracle_Edu
Special thanks to Arijit Ghosh, David Wright, Radhika Banka, and the OU Studio Team for helping us create this episode.
--------------------------------------------------------
Episode Transcript:
00:00
Welcome to the Oracle University Podcast, the first stop on your cloud journey. During this series of informative podcasts, we’ll bring you foundational training on the most popular Oracle technologies. Let’s get started!
00:26
Nikita: Hello and welcome to the Oracle University Podcast. I’m Nikita Abraham, Principal Technical Editor with Oracle University, and I’m joined by Lois Houston, Director of Innovation Programs.
Lois: Hi there! This is our second episode on OCI Container Engine for Kubernetes, and today we’re going to spend time discussing container registries with our colleague and senior OCI instructor, Mahendra Mehra.
Nikita: We’ll talk about how you can become proficient in managing Oracle Cloud Infrastructure Registry, a vital component in your container workflow.
00:58
Lois: Hi Mahendra, can you explain what Oracle Cloud Infrastructure Registry, or OCIR, is and how it simplifies the container image management process?
Mahendra: OCIR is an Oracle-managed registry designed to simplify the development-to-production workflow for developers. It offers a range of functionalities, serving as a private docker registry for internal use where developers can easily store, share, and manage container images.
The strength of OCIR lies in its high available and scalable architecture. Leveraging OCI to ensure reliable deployment of applications, developers can use OCIR not only as a private registry but also as a public registry, facilitating the pulling of images from public repositories for users with internet access.
01:55
Lois: But what sets OCIR apart?
Mahendra: What sets OCIR apart is its compliance with the Open Container Initiative standards, allowing the storage of container images conforming to the OCI specifications.
It goes a step further by supporting manifest lists, sometimes known as multi-architecture images, accommodating diverse architectures like ARM and AMD64. Additionally, OCIR extends its support to Helm charts. Security is a priority with OCIR, offering private access through a service gateway. This means that OCI resources within a VCN in the same region can securely access OCIR without exposing them to the public internet.
02:46
Nikita: OK. What are some other key advantages of OCIR?
Mahendra: Firstly, OCIR seamlessly integrates with the Container Engine for Kubernetes, ensuring a cohesive container management experience. In terms of security, OCIR provides flexibility by allowing registries to be either private or public, giving administrators control over accessibility.
It is intricately integrated with IAM, offering straightforward authentication through OCI Identity. Another notable benefit is regional availability. You can efficiently pull container images from the same region as your deployments. For high-performance, availability, and low-latency image operations, OCIR leverages the robust infrastructure of OCI, enhancing the overall reliability of image push and pull operations.
OCIR ensures anywhere access, allowing you to utilize container CLI for image operations from various locations, be it on the cloud, on-premises, or even from personal laptops.
03:57
Lois: I believe OCIR has repository quotas? Is there a cap on them?
Mahendra: In each enabled region for your tenancy, you can establish up to 500 repositories with a cumulative storage limit of 500 GB. Each repository is capable of holding up to 100,000 images. Importantly, charges apply only for stored images.
04:21
Nikita: That’s good to know, Mahendra. I want to move on to basic container registry concepts. Maybe we can start with what an image is.
Mahendra: Image is basically a read-only template with instructions for creating a container. It holds the application that you want to run as a container, along with any dependencies that are required. Container registry is an Open Container Initiative-compliant registry. As a result, you can store any artifacts that conform to Open Container Initiative specifications, such as Docker images, manifest lists, sometimes also known as multi-architecture images, and Helm charts.
05:02
Lois: And what’s a repository then?
Mahendra: It's a meaningfully named collection of related images which are grouped together for convenience in a container registry. There are different versions of the same source image, which are grouped together into the same repository.
You can have multiple images stored under this repository. The only thing that you need to keep changing is the image version. Every image version is given a tag. And the tag uniquely identifies the image.
05:33
Lois: Is it possible to make the repository public or private?
Mahendra: Depending upon your need, a repository can be made private or public. One important thing to note is that the user needs to have an OCI username and authentication token before being able to push/pull an image from the OCIR.
05:52
Nikita: There are so many terms that you come across when working with repositories and container registry, right? Could you take us through them and explain
how they relate to each other? I’ve heard of the region key and tenancy namespace.
Mahendra: The region key identifies the container registry region that you are using. A tenancy namespace is an auto-generated random and immutable string of alphanumeric characters. The tenancy namespace can be retrieved from the value of your object storage namespace field.
Repository name is the name of a repository in container registry, to and from which you can push and pull images. Repository names can include one or more slash characters and are unique across all the compartments in the entire tenancy.
You should note that although a repository name can include slash characters, the slash does not represent a hierarchical directory structure. It is simply one character in the string of characters. As a convenience, you might choose to start the name of different repositories with the same string. A registry identifier is the combination of your container registry region key and the tenancy namespace.
07:07
Lois: What about an image tag and an image path? How do they differ from each other?
Mahendra: A tag or an image tag is a string used to refer to a particular image in a known registry. The term "image name" is sometimes used as a shorthand way to refer to a particular image in a particular repository. A tag can be a numerical value or it can be a string. An image path is a fully qualified path to a particular image in a registry. It extends the repository path by adding tags associated with the image.
07:46
Do you want to stay ahead of the curve in the ever-evolving AI landscape? Look no further than our brand-new OCI Generative AI Professional course and certification. For a limited time only, we’re offering both the course and certification for free. So, don’t miss out on this exclusive opportunity to get certified on Generative AI at no cost. Act fast because this offer is valid only until July 31, 2024. Visit https://education.oracle.com/genai to get started. That’s https://education.oracle.com/genai.
08:24
Nikita: Welcome back! Mahendra, from what you’ve told us, OCIR seems like such a pivotal tool for modern containerized workflows, with its seamless integration, robust security measures, regional accessibility, efficient image management. So, how do we actually manage OCIR?
Mahendra: Managing OCIR can be done in three ways. Starting with managing the repository itself, followed by managing the images within the repository, and, last but not the least, managing the overall security of your repository alongside the images.
08:58
Nikita: Can we dive into each of these approaches in a little more detail? How does managing the repository itself work?
Mahendra: You can create an empty repository in a compartment and give it a name that's unique across all the compartments in the entire tenancy. There is a limit to the number of repositories you can have in a given region in a tenancy. So, when you no longer need a repository, it makes sense to delete it from the Oracle Cloud Infrastructure registry. Make a note that when you delete a repository, it can take up to 48 hours for the deletion to take effect and for the storage to actually be released.
When you create a new repository in Oracle Cloud Infrastructure Registry, you specify the compartment in which you want to create it. Having created the repository in one compartment, you can subsequently move it to a different compartment. The reasons can be many. It can be to change the users who are authorized to use the repository or to change how the billing for a repository is charged.
09:52
Lois: OK. And what about managing images within the repository?
Mahendra: You can view the images stored on OCIR using the OCI Console or using Docker images command from your Docker client after logging in to the OCIR repo. To push an image, you first used the Docker tag command to create a copy of the local source image as a new image. As a name for the new image, you specify the fully-qualified path to the target location in your container registry where you want to push the image, including the name of a repository.
In order to pull an image, you must be logged in into the OCIR registry using the auth token and use the Docker pull command followed by a fully-qualified name of the image you wish to download on your Docker client.
10:36
Nikita: What happens when you no longer need an old image or you simply want to clean up the list of image tags in a repository?
Mahendra: You can delete images from the Oracle Cloud Infrastructure Registry. You can undelete an image you've previously deleted for up to 48 hours after you deleted it. After that time, the image is permanently removed from the container registry. You can set up image retention policies to automatically delete images that meet particular selection criteria.
11:02
Lois: What sort of selection criteria?
Mahendra: Criterias can be images that have not been pulled for a certain number of days or images that have not been tagged for a certain number of days. It can also be images that have not been given particular Docker tags specified as exempt from the automatic deletion.
There's an hourly process that checks images against the selection criteria, and any that meet the selection criteria are automatically deleted. In each region in a tenancy, there's a global image retention policy. The default criteria of the policy is to retain all images so that no images are automatically deleted. However, you can change the global image retention policy so that the images are deleted if they meet certain criteria that you specify.
A region's global image retention policy applies to all the repository within that region unless it is explicitly overridden by one or more custom image retention policies. Only one custom image retention policy at a time can be applied to a repository. If a repository has already been added to a custom retention policy and you want to add repository to a different custom retention policy, you have to remove the policy from the first retention policy before adding it to the second one.
12:15
Lois: Mahendra, what should we keep in mind when we’re dealing with the global image retention policy?
Mahendra: The global image retention policy are specific to a particular region. To delete images consistently in different regions in your tenancy, you need to set up image retention policies in each region with identical selection criteria.
If you want to prevent images from being deleted on the basis of Docker tags they've been given, you need to specify those tags as exempt in a comma-separated list. When you want to clean up the list of images in a repository without actually deleting the images, you can remove the tags from the images in OCIR. Removing images is referred to as untagging.
12:53
Nikita: OK…and the last approach was managing the overall security of your repository alongside the images, right?
Mahendra: While managing security, you are given fine grained control over the operations that users are allowed to perform on repositories within the Container Registry. Using the concept of users and groups, you can control repository access by setting up identity access management policies at the tenancy and at the compartment level.
You can write policies to allow inspect, read, use, and manage operations on the repository based on the requirements. You can set up Oracle Cloud Infrastructure Registry to scan images in a repository for security vulnerabilities published in the publicly available common vulnerabilities and exposure databases. To perform image scanning, container registry makes use of the Oracle Cloud Infrastructure vulnerability-scanning service and vulnerability scanning REST API.
13:46
Nikita: What do I need to have in place before I can push and pull Docker images to and from Oracle Cloud Infrastructure Registry?
Mahendra: The first thing is, your tenancy must be subscribed to one or more of the regions in which the container registry is available. You can check the same within the Oracle documentation.
The next thing is, you need to have access to the Docker command line interface to push and pull images on your local machine. The third thing is, users must belong to a group to which a policy grants the appropriate permission or belong to a tenancies administrator group, which by default have access permissions on the container registry. Lastly, user must already have an Oracle Cloud Infrastructure username and an authentication token, which enables them to perform operations on the container registry.
14:29
Lois: Thank you, Mahendra, for sharing your insights on OCIR with us. To watch demos on managing OCIR, visit mylearn.oracle.com and search for the OCI Container Engine for Kubernetes Specialist course.
Nikita: Mahendra will be back next week to walk us through the basics of Kubernetes. Until then, this is Nikita Abraham…
Lois: And Lois Houston, signing off!
14:53
That’s all for this episode of the Oracle University Podcast. If you enjoyed listening, please click Subscribe to get all the latest episodes. We’d also love it if you would take a moment to rate and review us on your podcast app. See you again on the next episode of the Oracle University Podcast.
You Might Like
