consul = Consul(host="consul", port=consul_port)

Where

• consul in host="consul" is the hostname of the container running consul server.
• consul_port in port=consul_port is 8500 (the default consul port).

check = Check.http(f"http://{ip}:{service_port}/", interval="10s", timeout="5s", deregister="1s")

Where

• ip is the current service address (which we are registering).
• service_port is the current service port.
• Ending the url with simply / means it will check the default url.
  • So we should have something like this in fast api code:

  @app.get("/")
  def index():
      return "Service1"

• interval="10s" means that the health check will occur each 10 seconds.
• timeout="5s 5 seconds is the response timeout.
• deregister="1s" after how much time will the service go from 'critical state' to 'deregistered'.
  • Note however that consul takes a minimum of around 1 minute to perform such action.
  • So putting anything less than that won't change consul's default.
• Check more details in the official consul docs.

service.register(service_name, service_id=service_name, address=ip, port=service_port, check=check)

Where

• service_name is the service name and id so it should be unique.
• ip is the same we used in the check, that is, the current service address.
• service_port, same story for this one.
• check is the check we created earlier.

• To get the local ip address (which we do in get_ip()) we use a configuration file.
• If you plan on using this only inside docker, then you can simply use eth0 as a network interface.
• In windows it is different so we provide a config file but it won't work on your device as it is different in every machine.

service_list = agent.services()
service_info = service_list[service_id]

• agent.services() returns the registered services.
• service_id is the service we are searching for its address and port (or other details).

return service_info['Address'], service_info['Port']

• Since service_info is dict object so we can get the response details as shown.
• Other attributes that can be used can be found in the official docs.

docker-compose up -d

We suggest using the simple docker compose file.

If you want to use python consul in your project, here is how you can do it:

• First you need to use pip freeze > requirements.txt to add the dependencies.
  • Note that we did this in a virtual environment so we only had the dependencies we used in the project.
• We provide a Dockerfile which copies the needed files and runs the app using uvicorn.
• To build it into a docker image use docker build . -t service-name.
• Don't forget to change the service name in the docker compose file with your image.

• Available on localhost:8500/ui/.
• Here you can see all the services and their health status.

We host

• service1 on localhost:8010.
• service2 on localhost:8020.

• / index page, used by the health check.
• /sentence-dependent calls service2 using consul.
• /sentence-independent gets called by service2 using consul.

• / index page, used by the health check.
• /text calls service1 using consul.
• /words gets called by service1 using consul.