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Run the Algorithm Viewer with ShinyProxy

Source: vignettes/howto-shinyproxy.Rmd
howto-shinyproxy.Rmd

Audience: Deployers who want to serve the Algorithm Viewer to multiple users, with each user session running in its own isolated container.

Prerequisites:

For installing Java and Docker, see the ShinyProxy Getting Started Guide.

What ShinyProxy gives you

ShinyProxy is an open-source server for hosting Shiny apps as a multi-user service. When a user opens the app, ShinyProxy launches a dedicated Docker container for that session and tears it down when the session ends. This provides per-user isolation and container-based scaling — useful for a shared or public deployment.

Step 1 — Build the Algorithm Viewer image

ShinyProxy launches the app from a Docker image. Build it first, tagged algorithm-viewer:latest (the tag the sample config expects):

docker build -t algorithm-viewer:latest .

See the Docker how-to for details.

Step 2 — Review the sample application.yml

The repository root contains a sample application.yml — a ShinyProxy configuration that already defines an algorithm-viewer app spec pointing at the algorithm-viewer:latest image:

proxy:
  title: Big Life Lab Shiny Apps
  port: 8080
  authentication: none
  docker:
    port-range-start: 20000
  specs:
    - id: algorithm-viewer
      display-name: Algorithm Viewer
      description: An application for visualizing health risk prediction algorithms, displaying various curves and comparisons.
      container-image: algorithm-viewer:latest

By default it runs with authentication: none and serves on port 8080.

To require a login, set authentication: simple and define users. Never hard-code real credentials in application.yml. ShinyProxy is a Spring Boot application, so it resolves ${ENV_VAR} placeholders from environment variables with an optional ${ENV_VAR:default} fallback. The sample config is already set up for this:

proxy:
  authentication: simple
  users:
    - name: ${SHINYPROXY_USERNAME:biglifelab}
      password: ${SHINYPROXY_PASSWORD}
      groups: scientist

Set a strong password via an environment variable before starting ShinyProxy:

export SHINYPROXY_USERNAME=biglifelab
export SHINYPROXY_PASSWORD='a-strong-secret'

When running ShinyProxy in Docker, either forward values already exported in your shell (the bare -e NAME form copies the value from the host shell):

docker run -e SHINYPROXY_USERNAME -e SHINYPROXY_PASSWORD ... shinyproxy

or set them inline:

docker run -e SHINYPROXY_USERNAME=biglifelab \
           -e SHINYPROXY_PASSWORD='a-strong-secret' ... shinyproxy

The values are substituted at startup and never committed in plain text.

Step 4 — Start ShinyProxy

Run ShinyProxy with the application.yml in the working directory, following the ShinyProxy documentation for your chosen method (the standalone JAR or the official ShinyProxy Docker image). ShinyProxy reads application.yml, and when a user opens the Algorithm Viewer it launches a container from the algorithm-viewer:latest image on a port from the port-range-start range.

Open http://localhost:8080 to reach the ShinyProxy landing page and launch the Algorithm Viewer.

Customization notes

  • Logo and theme. The sample config has commented-out logo-url and template-path options for custom branding.
  • Logging. ShinyProxy writes to shinyproxy.log as configured under the logging: key.
  • Which algorithm is served. The container serves whatever its image is configured to run — by default the built-in HTNPoRT configuration. To serve a different algorithm, build an image that bundles your algorithm and config (see the Docker how-to) and reference that image in container-image.

Next steps