Fiware: Create Postgresql

Question

Having Cygnus installed and running (subscribed to Orion). Orion receives notifications from client (via the ioagent). How do I start and create the postgresql databases for persistence?

Accessing fiware from remote server. Not sure what command to execute and start postgres.

Answer 1

There is a FIWARE Tutorial available about persisting historic data to PostGres

Within docker-compose PostGres can be set-up as follows:

postgres-db:
    image: postgres
    hostname: postgres-db
    container_name: db-postgres
    expose:
        - "5432"
    ports:
        - "5432:5432"
    networks:
        - default
    environment:
        - "POSTGRES_PASSWORD=password"
        - "POSTGRES_USER=postgres"
        - "POSTGRES_DB=postgres"

The Cygnus configuration mirrors the PostGre config as shown:

cygnus:
    image: fiware/cygnus-ngsi
    hostname: cygnus
    container_name: fiware-cygnus
    networks:
        - default
    depends_on:
        - postgres-db
    expose:
        - "5080"
    ports:
        - "5050:5050"
        - "5080:5080"
    environment:
        - "CYGNUS_POSTGRESQL_HOST=postgres-db"
        - "CYGNUS_POSTGRESQL_PORT=5432"
        - "CYGNUS_POSTGRESQL_USER=postgres"
        - "CYGNUS_POSTGRESQL_PASS=password"
        - "CYGNUS_SERVICE_PORT=5050"
        - "CYGNUS_API_PORT=5080"
        - "CYGNUS_POSTGRESQL_ENABLE_CACHE=true"

The database instance should be instantiated when a subscription to Cygnus is fired.

for example:

curl -iX POST \
  'http://orion:1026/v2/subscriptions' \
  -H 'Content-Type: application/json' \
  -H 'fiware-service: <xxxxxx>' \
  -H 'fiware-servicepath: <yyyyyy>' \
  -d '{
  "description": "Notify Cygnus of all context changes",
  "subject": {
    "entities": [
      {
        "idPattern": ".*"
      }
    ]
  },
  "notification": {
    "http": {
      "url": "http://cygnus:5050/notify"
    },
    "attrsFormat": "legacy"
  },
  "throttling": 5
}'