about-learning-center.md

Learning Center overview

The Learning Center provides a platform for hosting workshops. Although Learning Center requires Kubernetes to run, and is being used to teach users about Kubernetes, it can also be used to host training for other purposes as well. It can for example, be used to help train users in web based applications, use of databases, or programming languages, where the user has no interest or need for Kubernetes.

Overall goals

The use case scenarios which Learning Center is supported are as follows.

• Supervised workshops. This can be a workshop run at a conference, at a customer site, or purely online. The workshop has a set time period and you know the maximum number of users to expect. After the training has completed, the Kubernetes cluster created for the workshop will be destroyed.

• Temporary learning portal. This is for when you must provide access to a small set of workshops for a short duration for hands on demos at a conference vendor booth. Users will select which topic they want to learn about and do that workshop. The workshop instance will be created on demand. When they have finished the workshop, that workshop instance will be destroyed to free up resources. After the conference has finished, the Kubernetes cluster will be destroyed.

• Permanent learning portal. Similar to the temporary learning portal, but will be run on an extended basis as a public web site where anyone can come and learn at any time.

• Personal training or demos. This is where anyone who wants to run a workshop on their own Kubernetes cluster to learn that topic, or where a product demo was packaged up as a workshop and they want to use it to demonstrate the product to a customer. The workshop environment may be destroyed when complete, but there is no need for the cluster to be destroyed.

When running workshops, where ever possible a shared Kubernetes cluster will be used so as to reduce the amount of set up required. This works for developer focused workshops as it is usually not necessary to provide elevated access to the Kubernetes cluster, and role based access controls (RBAC) may be used to prevent users from interfering with each other. Quotas can also be set so that users are restricted to how much resources they can use.

In the case of needing to run workshops which deal with cluster operations, for which users need cluster admin access, a separate cluster will be created for each user. Learning Center doesn't deal with provisioning clusters, only with deploying a workshop environment in a cluster after it exists.

In catering for the preceding scenarios, the set of primary requirements related to creation of workshop content, and what can be done at runtime are as follows.

• Everything for the workshop needs to be stored in a Git repository, with no dependency on using a special web application or service to create a workshop.

• Use GitHub as a means to distribute workshop content. Alternatively, you can distribute the workshop as a container image. The latter is necessary if special tools must be installed for use in a workshop.

• The instructions for a user to do the workshop will be provided as Markdown or AsciiDoc files.

• Instructions may be annotated as executable commands so that when clicked on in the workshop dashboard they will execute for the user in the appropriate terminal to avoid mistakes when commands are entered manually.

• Text may be annotated as copy able so that when clicked on in the workshop dashboard it will be copied into the browser paste buffer ready for pasting into the terminal or other web application.

• Each user is provided access to one or more namespaces in the Kubernetes cluster unique to their session. For Kubernetes based workshops, this is where applications ill be deployed as part of the workshop.

• Additional Kubernetes resources specific to a workshop session may be pre-created when the session is started. This is to enable the deployment of applications for each user session.

• Additional Kubernetes resources common to all workshop sessions can be deployed when the workshop environment is first created. This is to enable deployment of shared applications used by all users.

• Application of resource quotas on each workshop session to control how much resources users can consume.

• Application of role based access control (RBAC) on each workshop session to control what users can do.

• Ability to provide access to an editor (IDE) in the workshop dashboard in the web browser for users to use to edit files during the workshop.

• Ability to provide access to a web based console for accessing the Kubernetes cluster. Use of the Kubernetes dashboard or Octant is supported.

• Ability to integrate additional web based applications into the workshop dashboard specific to the topic of the workshop.

• Ability for the workshop dashboard to display slides used by an instructor in support of the workshop.

Platform architectural overview

The Learning Center relies on a Kubernetes Operator to perform the bulk of the work. The actions of the operator are controlled by using a set of custom resources specific to the Learning Center.

There are multiple ways of using the custom resources to deploy workshops. The primary way is to create a training portal, which in turn then triggers the setup of one or more workshop environments, one for each distinct workshop. When users access the training portal and select the workshop they want to do, the training portal allocates to that user a workshop session (creating one if necessary) against the appropriate workshop environment, and the user is redirected to that workshop session instance.

You can associate each workshop session with one or more Kubernetes namespaces specifically for use during that session. Role based access control (RBAC) applied to the unique Kubernetes service account for that session, ensures that the user can only access the namespaces and other resources that they are allowed to for that workshop.

In this scenario, the custom resource types that come into play are:

• Workshop - Provides the definition of a workshop. Preloaded by an admin into the cluster, it defines where the workshop content is hosted, or the location of a container image which bundles the workshop content and any additional tools required for the workshop. The definition also lists additional resources that must be created which are to be shared between all workshop sessions, or for each session, with details of resources quotas and access roles required by the workshop.

• TrainingPortal - Created by an admin in the cluster to trigger the deployment of a training portal. The training portal can provide access to one or more distinct workshops defined by a Workshop resource. The training portal provides a web based interface for registering for workshops and accessing them. It also provides a REST API for requesting access to workshops, allowing custom front ends to be created which integrate with separate identity providers and which provide an alternate means for browsing and accessing workshops.

• WorkshopEnvironment - Used by the training portal to trigger the creation of a workshop environment for a workshop. This causes the operator to set up a namespace for the workshop into which shared resources will be deployed, and where the workshop sessions are run.

• WorkshopSession - Used by the training portal to trigger the creation of a workshop session against a specific workshop environment. This causes the operator to set up any namespaces specific to the workshop session and pre-create additional resources required for a workshop session. Workshop sessions may be created up front in reserve, to be handed out when requested, or created on demand.