YAML File Value Overriding in Hubploy

There are several .yaml files present in the hubploy-template repository. It can be unclear which settings go in which files. This topic hopes to clear that up a bit. As a reminder, here is the directory structure that Hubploy expects (minimized for focus on the yaml files):

├── .github
│   └── workflows
│       ├── deploy.yaml
│       └── image-build.yaml
├── deployments
│   └── hub
│       ├── config
│       │   ├── common.yaml
│       │   ├── prod.yaml
│       │   └── staging.yaml
│       ├── hubploy.yaml
│       └── secrets
│           ├── aws-ecr-config.cfg
│           ├── aws-eks-config.cfg
│           ├── prod.yaml
│           └── staging.yaml
└── hub
    ├── Chart.yaml
    ├── requirements.lock
    ├── requirements.yaml
    ├── templates
    │   ├── jupyter-notebook-config.yaml
    │   └── nfs-pvc.yaml
    └── values.yaml

GitHub Action Files

The two files under .github/workflows/ manage individual GitHub Actions for Hubploy. They are independent of most of the rest of Hubploy.

JupyterHub Deployment Files

The main value files are related to the JupyterHub Helm release. The lowest level of these are specified in hub/values.yaml via:

jupyterhub: {}

The braces can be removed once there are yaml values in the file, but they are needed if this block is empty. Appropriate values to put in this file are those that will span both versions of all JupyterHubs that you will deploy with Hubploy, as this file will be used for all of them.

The next file in the heirarchy is deployments/hub/config/common.yaml. This file covers deployment values that are common to both the staging and production hubs that Hubploy named “hub,” or what you had changed that folder name to. If there are multiple JupyterHubs being managed , each one will have a common.yaml. Values in this file will overwrite hub/values.yaml.

The next two files in the heirarchy are also in the config folder: staging.yaml and prod.yaml. These contain values for the staging and production hubs, respectively. Values in these files will override the previous two. These two files do not override each other ever since they are for two different hubs.

The last files in the heirarchy are under the secrets directory. These are set in a folder that we tell git-crypt to encrypt when pushing code to GitHub. In general, there shouldn’t be anything in these files that overwrites the other staging.yaml and prod.yaml. It is more expected that values in these files will overwrite default credentials or paths present in the first two files.

A quick summary of the heirarchy follows in descending priority (lower overwrites higher) but ascending generality (higher applies to more hubs):


Local Hub Helm Chart Files

Everything under the hub folder is related to the Helm Chart. In Chart.yaml, the main specification is what the Chart is named and what version you are on. In requirements.yaml, the JupyterHub Helm chart is listed as the only dependency and you can pick a specific version. values.yaml is used to provide the lowest level of values for JupyterHub configuration and other deployment pieces that are present in the templates/ folder or other dependencies you choose to add to the Helm chart.