Created question in FIWARE Q/A platform on 22-11-2021 at 06:11
Please, ANSWER this question AT https://stackoverflow.com/questions/70061849/error-pool-overlaps-with-other-one-on-this-address-space

Question:
ERROR: Pool overlaps with other one on this address space

Description:
I'm trying to implement this tutorial. The "docker-compose" content is this :

1. WARNING: Do not deploy this tutorial configuration directly to a production environment
   #
2. The tutorial docker-compose files have not been written for production deployment and will not
3. scale. A proper architecture has been sacrificed to keep the narrative focused on the learning
4. goals, they are just used to deploy everything onto a single Docker machine. All FIWARE components
5. are running at full debug and extra ports have been exposed to allow for direct calls to services.
6. They also contain various obvious security flaws - passwords in plain text, no load balancing,
7. no use of HTTPS and so on.
9. This is all to avoid the need of multiple machines, generating certificates, encrypting secrets
10. and so on, purely so that a single docker-compose file can be read as an example to build on,
11. not use directly.
13. When deploying to a production environment, please refer to the Helm Repository
14. for FIWARE Components in order to scale up to a proper architecture:
16. see: https://github.com/FIWARE/helm-charts/
    #
    version: "3.5"
    services:
17. Orion is the context broker
    orion:
    image: fiware/orion:latest
    hostname: orion
    container_name: fiware-orion
    depends_on:

• mongo-db
  networks:
• default
  expose:
• "1026"
  ports:
• "1026:1026"
  command: -dbhost mongo-db -logLevel DEBUG
  healthcheck:
  test: curl --fail -s http://orion:1026/version || exit 1
  interval: 5s

1. Tutorial displays a web app to manipulate the context directly

tutorial:
image: fiware/tutorials.context-provider
hostname: iot-sensors
container_name: fiware-tutorial
networks:

• default
  expose:
• "3000"
• "3001"
  ports:
• "3000:3000"
• "3001:3001"
  environment:
• "DEBUG=tutorial:*"
• "PORT=3000"
• "IOTA_HTTP_HOST=iot-agent"
• "IOTA_HTTP_PORT=7896"
• "DUMMY_DEVICES_PORT=3001"
• "DUMMY_DEVICES_API_KEY=4jggokgpepnvsb2uv4s40d59ov"
• "DUMMY_DEVICES_TRANSPORT=HTTP"
  iot-agent:
  image: fiware/iotagent-ul:latest
  hostname: iot-agent
  container_name: fiware-iot-agent
  depends_on:
• mongo-db
  networks:
• default
  expose:
• "4041"
• "7896"
  ports:
• "4041:4041"
• "7896:7896"
  environment:
• "IOTA_CB_HOST=orion"
• "IOTA_CB_PORT=1026"
• "IOTA_NORTH_PORT=4041"
• "IOTA_REGISTRY_TYPE=mongodb"
• "IOTA_LOG_LEVEL=DEBUG"
• "IOTA_TIMESTAMP=true"
• "IOTA_MONGO_HOST=mongo-db"
• "IOTA_MONGO_PORT=27017"
• "IOTA_MONGO_DB=iotagentul"
• "IOTA_HTTP_PORT=7896"
• "IOTA_PROVIDER_URL=http://iot-agent:4041"

1. Database
   mongo-db:
   image: mongo:3.6
   hostname: mongo-db
   container_name: db-mongo
   expose:

• "27017"
  ports:
• "27017:27017"
  networks:
• default
  command: --bind_ip_all --smallfiles
  volumes:
• mongo-db:/data
  healthcheck:
  test: |
  host=`hostname --ip-address || echo '127.0.0.1'`;
  mongo --quiet $host/test --eval 'quit(db.runCommand( { ping: 1 }

  ).ok ? 0 : 2)' && echo 0 || echo 1
  interval: 5s

networks:
default:
ipam:
config:

• subnet: 172.18.1.0/24
  volumes:
  mongo-db: ~

But when I run the docker compose with the command "docker-compose up -d" I get this error :
*WARNING: The host variable is not set. Defaulting to a blank string.
Creating network "fiware_default" with the default driver
ERROR: Pool overlaps with other one on this address space*

I also get these networks by running the command "docker network ls" :
*NETWORK ID NAME DRIVER SCOPE
78403834b9bd bridge bridge local
1dc5b7d0534b hadig_default bridge local
4162244c37b0 host host local
ac5a94a89bde none null local*

I see no conflict with the name "fiware_default". where is the problem?