View Project in Designer hero In this exercise, we will create a simple web service which streams data to the client. The projects main node is the web.async_http node which listens for incoming HTTP requests. It accepts an authentication node and needs to be terminated by a web.async_finish_request node. Begin by dragging the following nodes onto the workspace:
  • web.async_http
  • web.async_finish_request
Then create a new node by right clicking on the workspace and selecting Create Node. This node will be used to generate the data that will be streamed to the client. Rename the new code and call it Hello, world. Connect them according to the image below: basic_node_setup.png Right click on the Hello, world-node and commit the following code: 
from mirmod import miranda

g_counter = 0

@wob.init()
def init(self):
  self.http = None

wob.passthrough("state","http","http")

@wob.execute()
async def execute(self):
  global g_counter
  param = self.http.payload["prompt"] if "prompt" in self.http.payload else "no prompt given"
  assert self.http != None
  print ("g_counter= ", g_counter)
  await self.http.event("data","{} {}".format( param, g_counter))
  g_counter += 1
Click the run button on the right sidebar and the HTTP server will start listening on port 443 on the following address: https://<job id>.p.mainly.cloud The <job id> you find if you click the job indocator in the top right of the workspace screen: job_state_indicator.png Here we see that the ID is 01hwawbp7aam0cx8jcwzt38vtj and if we go to https://01hwawbp7aam0cx8jcwzt38vtj.p.mainly.cloud/docs we can verify that the service is running. Next we need to write the client code. For this we need Visual Studio code or similar and an installed python environment on our desktop. This is the client code we’re going to use: 
import requests
def prompt_mainly(endpoint, prompt):
  url = f"https://01hwawbp7aam0cx8jcwzt38vtj.p.mainly.cloud/{endpoint}"
  payload = { "prompt": prompt }
  resp = requests.post(url, json=payload, stream=True)
  d= ""
  for r in resp:
    d += r.decode("utf8")
  print (d)
We call the function like this: 
prompt_mainly("stream_run_payload","Hello, world")
We should expect to see the following output: 
event: data
data: "Hello, world 0"