DataHub Base Path Configuration

This document describes how to configure DataHub to run from a custom base path (e.g., /my-app/ instead of /).

Overview

DataHub now supports serving from a custom base path, allowing you to:

Serve DataHub from a subdirectory (e.g., https://company.com/datahub/)
Deploy multiple DataHub instances on the same domain
Integrate DataHub behind reverse proxies with path-based routing

Configuration

Environment Variables

Set the following environment variable to configure the base path:

bash

export DATAHUB_BASE_PATH="/my-app"

Important Notes:

The base path should start with / but not end with /
Examples: /datahub, /my-app, /tools/datahub
Leave empty or unset for root path deployment

Component Configuration

The base path configuration affects three main components:

1. Frontend (datahub-web-react)

The frontend determines the base path using multiple detection methods (in priority order):

Environment Variable (highest priority):

bash

# Set in .env file or environment
REACT_APP_BASE_PATH=/my-app

Server Configuration (fetched from /config endpoint):
- The React app fetches base path from the backend's configuration
- Most reliable for production deployments
URL Analysis (fallback):
- Analyzes current URL to detect base path
- Used when server config is unavailable

Development Configuration:

bash

# Method 1: Environment variable (recommended for development)
echo "REACT_APP_BASE_PATH=/my-app" >> .env
yarn start  # Development server at http://localhost:3000/my-app

# Method 2: Using Vite preview (for testing production builds)
yarn build
npx vite preview --port 3001  # Uses base path from REACT_APP_BASE_PATH
# Accessible at: http://localhost:3001/my-app

# Method 3: Override base path via command line
npx vite preview --port 3001 --base /custom-path

Production Behavior:

Automatically fetches base path from server configuration
Falls back to URL detection if server config unavailable
Provides console warnings to help with debugging

2. DataHub Frontend Service (Play Framework)

The Play Framework application supports base path through:

datahub.basePath configuration in application.conf
play.http.context for Play Framework native support
Environment variable: DATAHUB_BASE_PATH

3. Metadata Service (Spring Boot)

The metadata service (GMS) supports base path through:

server.servlet.context-path in application.yaml
Environment variable: DATAHUB_BASE_PATH

Deployment Examples

Docker Compose

yaml

version: "3.8"
services:
  datahub-frontend:
    environment:
      - DATAHUB_BASE_PATH=/datahub
	  - PLAY_HTTP_CONTEXT=/datahub

  datahub-gms:
    environment:
      - DATAHUB_BASE_PATH=/datahub

Kubernetes

yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: datahub-frontend
spec:
  template:
    spec:
      containers:
        - name: datahub-frontend
          env:
            - name: DATAHUB_BASE_PATH
              value: "/datahub"
            - name: DATAHUB_GMS_BASE_PATH
              value: "/datahub"
            - name: PLAY_HTTP_CONTEXT
              value: "/datahub"
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: datahub-gms
spec:
  template:
    spec:
      containers:
        - name: datahub-frontend
          env:
            - name: DATAHUB_BASE_PATH
              value: "/datahub"
            - name: DATAHUB_GMS_BASE_PATH
              value: "/datahub"

Limitations

Base path must be consistent across all DataHub components
Changing base path requires restat of GMS and front end deployments.
Testing of multiple DataHub environments served by the same URL, e.g. http://example.com/datahub1, http://example.com/datahub2, hasn't been extensively validated.