Configuring Registry

Drycc Workflow's builder component relies on a registry for storing application docker images.

Drycc Workflow ships with a registry component by default, which provides an in-cluster Docker registry backed by the platform-configured object storage. Operators might want to use an off-cluster registry for performance or security reasons.

Configuring Off-Cluster Private Registry

Every component that relies on a registry uses two inputs for configuration:

  1. Registry Location environment variable named DRYCC_REGISTRY_LOCATION
  2. Access credentials stored as a Kubernetes secret named registry-secret

The Helm chart for Drycc Workflow can be easily configured to connect Workflow components to off-cluster registry. Drycc Workflow supports external registries which provide either short-lived tokens that are valid only for a specified amount of time or long-lived tokens (basic username/password) which are valid forever for authenticating to them. For those registries which provide short lived tokens for authentication, Drycc Workflow will generate and refresh them such that the deployed apps will only have access to the short-lived tokens and not to the actual credentials for the registries.

When using a private registry the docker images are no longer pulled by Drycc Workflow Controller but rather are managed by Kubernetes. This will increase security and overall speed, however the port information can no longer be discovered. Instead the port information can be set via drycc config:set PORT=<port> prior to deploying the application.

Drycc Workflow currently supports:

  1. off-cluster: Any provider which supports long-lived username/password authentication, such as Azure Container Registry, Docker Hub, quay.io, or a self-hosted Docker registry.

Configuration

  1. If you haven't already fetched the values file, do so with helm inspect values drycc/workflow > values.yaml
  2. Update registry location details by modifying the values file:
    • Update the registry_location parameter to reference the registry location you are using: off-cluster, ecr, gcr
    • Update the values in the section which corresponds to your registry location type.

You are now ready to helm install drycc/workflow --namespace drycc -f values.yaml using your desired registry.

Examples

Here we show how the relevant parts of the fetched values.yaml file might look like after configuring for a particular off-cluster registry:

Azure Container Registry (ACR)

After following the docs and creating a registry, e.g. myregistry, with its corresponding login server of myregistry.azurecr.io, the following values should be supplied:

global:
...
  registry_location: "off-cluster"
...
registry-token-refresher:
...
  registry:
    hostname: "myregistry.azurecr.io"
    organization: "myorg"
    username: "myusername"
    password: "mypassword"
...

Note: The mandatory organization field (here myorg) will be created as an ACR repository if it does not already exist.

Quay.io

global:
...
  registry_location: "off-cluster"
...
registry-token-refresher:
...
  registry:
    hostname: "quay.io"
    organization: "myorg"
    username: "myusername"
    password: "mypassword"
...