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Lepus

Repository

FIWARE-Lepus is an NGSI-LD wrapper for use with NGSI-v2 Context Brokers. It understands the NGSI-LD endpoints and inputs, converts them to NGSI-v2, makes a request to the NGSI-v2 broker behind it and transforms responses back to NGSI-LD using a fixed JSON-LD @context. It supports the NGSI-LD federationOps endpoints only and is designed to be used as a registered source with NGSI-LD Context Brokers in federation mode.

graph LR
  A[NGSI-v2 Context Broker] --- B[Lepus];
  B ---|NGSI-LD| C[Client];

Getting started

Warning

Lepus is a library still in development. It is considered untested and experimental. Errors may occur.

Create a docker-compose.yml file with the following config. Please, replace NGSI_V2_CONTEXT_BROKER with the URL / IP address of your NGSI-v2 Context Broker. Also set CONTEXT_URL to the desired context (for instance WasteManagement context). 

version: '3.9'
services:
  lepus:
    image: quay.io/fiware/lepus
    build:
      context: .
      dockerfile: Dockerfile
    hostname: adapter
    container_name: lepus
    networks:
      - default
    expose:
      - "3000"
    ports:
      - "3000:3000"
    environment:
      - DEBUG=adapter:*
      - NGSI_V2_CONTEXT_BROKER=http://orion2:1026/v2
      - CONTEXT_URL=https://fiware.github.io/tutorials.Step-by-Step/tutorials-context.jsonld
      - NOTIFICATION_RELAY_URL=http://adapter:3000/notify
      - NODE_TLS_REJECT_UNAUTHORIZED=0
networks:
  default:

Create and start the container by using the following command:

 docker compose up

Set-up your AI service / client so it points to 127.0.0.1.1:3000.

Debugging

As mentioned above, Lepus is still in its early stages, so it lacks some features, and wild bugs may appear. In order to make it easier to detect and report errors, a developing / debugging repository was created. If you find any issues or want to request a feature, please, open a new issue in the official repository.

Steps to run the development version (it is necessary to have Node.js installed):

  1. Clone the repository and navigate to its root folder: 

    git clone https://github.com/CitCom-VRAIN/lepus-dev && cd lepus-dev

  2. Install dependencies 

    npm install

  3. Run 

    npm start

Track and status of detected errors

  • Missing NGSILD-Tenant header (equivalent to Fiware-Service)
  • Missing scopeQ parameter (equivalent to Fiware-ServicePath)
  • Default response timeout too low for the VLCi platform
    • Use NGSI_V2_TIMEOUT environment variable to set a custom value (1000ms by default)
  • Missing @context property when requesting entities
  • HTTPS / SSL problems
    • Lepus' protocol is http. It should be fine for working locally and testing purposes
    • NODE_TLS_REJECT_UNAUTHORIZED=0 must be set to avoid SSL certificate checking problem
  • Static context