Automating Hyrax Container and Helm Chart Publishing

Date: 12/02/2021

Time: 14:00 PST/17:00 EST

Zoom URL: https://princeton.zoom.us/my/jrgriffiniii

Attendees

• tamsin johnson (UC Santa Barbara)

• Alexandra Dunn (UC San Diego)

• James Griffin (Princeton University Library)

Overview

• Hyrax Containers

  • https://docs.docker.com/get-started/overview/

• Kubernetes (k8s)

  • Many Containers, there is a need to configure these into a set of services which can interface/communicate

  • Typically, the architecture is oriented towards running one (or a limited number of processes) per container

    • Hence, a Rails application runs in one container, a key/value store in another container, Solr in another container…

  • This is similar to Docker Compose, but at a much larger scale, with an extensive API for clients to query or update

    • API provides users to declare and set the state of the entire system of Containers

• Helm Charts for Hyrax

  • https://helm.sh/docs/topics/charts/#helm

    • Package manager for k8s

      • Essentially, k8s will take a set of YAML files to define the state of the cluster of the containers

      • As such, Helm provides a templating language/domain-specific language (with variables) for describing the state of the container cluster

        • The actual application code within the container, then, can be set

        • (e. g. setting the version of Solr, or certain customizations, etc.)

        • A repeatable pattern for deploying many Hyrax applications

• Container Registries

  • Open Container Initiative (OCI) artifact registry

    • Artifacts can be container images, but also, other binaries (e. g. software binaries)

    • Providing authentication is supported

      • UCSB and UCSD have had experience sharing a registry

    • Helm charts permit one to define the images deployed, the ports exposed, and the network topology (to some extent)

    • k8s itself manages the pulling of the container images and manages the resources used to provision the container

      • Hence, k8s needs to be able to access the credentials required to query and pull the container registry

    • Registry can serve as a repository for other artifacts, including Helm Charts

      • This is experimentally supported at the moment

      • With a generalized registry, there can also be Ruby Gems, etc.

      • GitHub is taking this approach

  • GitHub Packages

    • https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry

Notes

• Hyrax Container

  • Samvera provides Dockerfiles for running Hyrax

  • K8s

• <To be drafted>