Hi I am totally new to Prefect and trying to figure things out. I have successfully deployed Prefect Server using helm with my own ingress host. Now I am trying to register flow in my own notebook and wondering how to connect to my own server. Can someone guide me?

Hi @Yongchan Hong, you need you set your backend to server with

prefect backend server

and also in your

config.toml

file, point to the server address with

[server]
endpoint = "YOUR_MACHINES_PUBLIC_IP:4200/graphql"

@Kevin Kho Hi Kevin! So I am trying to use my own Jupyter Hub cluster, and wondering where to find config.toml inside my Jupyter Hub cluster. Can you guide me through?

You don’t necessarily need it as a

config.toml

. You can have an environment variable

PREFECT__SERVER___ENDPOINT

also and it will do the same thing

@Kevin Kho Why is it telling me to set API key for authentication? Here is my code:

!prefect backend server
import os
os.environ['PREFECT_SERVER__ENDPOINT'] = "<https://prefect-apollo-dev.xtrm-data.io/graphql>"
from prefect import Client
client = Client()
client.create_project(project_name="Hello, World!")

Is this from a new kernel? Because when

prefect

is imported, it loads in the config (including the env variables). So the environment variable needs to be set before Prefect is imported. Your order is correct, but if it’s asking for an API key, it looks like it didn’t take effect

Thanks for the support. Do you mind if I can DM you? Or is talking through thread more convenient? Feels like my understanding about prefect is a bit low. Now it shows me connection refused error with:

HTTPConnectionPool(host='localhost', port=4200): Max retries exceeded with url: / (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f070a1b2510>: Failed to establish a new connection: [Errno 111] Connection refused'))

@Kevin Kho

Uhh the thread is fine I will see it or sometimes my colleagues will jump in too. This looks like you did not set the address of the server when trying to connect because it’s still

localhost

right? You need to point to your server with your

config.toml

file.

[server]
endpoint = "YOUR_MACHINES_PUBLIC_IP:4200/graphql"

Yeah I have deployed Prefect Helm with my own ingress. Now I am trying to connect outside, which is from jupyterhub, and I set

PREFECT__SERVER___ENDPOINT

as you told me… but it is still not working. @Kevin Kho Am I understanding something differently?

Oops sorry I mistook this for another similar thread going on. Yeah it looks like the env variable is not taking effect so it’s probably better we do it through the

config.toml

. I don’t know where this is on JupyterHub though. Give me a second to look

Thanks 🙏 Hope I an do something with config.toml since I am JupyterHub and cant find one

Do you have a

~/.prefect

directory?

You saved me! It works after manually creating config.toml. Thank you so much. @Kevin Kho

Nice!

So quick question about KubernetesRun - should i specify service_account_name and image when I want to use Kubernetes Agent?

Yes otherwise it just uses the default (default Prefect image). The image you specify just needs to be in a place the agent can pull it from

Okay this may sound dumb - but task is pending infinitely…So I register project and try to run flow.. from prefect import task, Flow, Parameter from prefect.run_configs import KubernetesRun

run_config = KubernetesRun(
        labels=["dev"],
        service_account_name="prefect-server-serviceaccount"
    )

@task(log_stdout=True)
def say_hello(name):
    print("Hello, {}!".format(name))


with Flow("My Second Flow", run_config=run_config) as flow:
    name = Parameter('name')
    say_hello(name)


flow.register(project_name="Hello, World!")

client.create_flow_run(flow_id='5bcaf7c8-e8ac-4b4e-9f05-527dd610a12a', parameters={'name':'world'})

But it seems like it create flow run but it never actually runs at all… Is my agent configuration wrong? Also, when just run flow like flow.run(name=‘world’), is it running inside local agent? Sorry for repeated question 😞 @Kevin Kho

This sounds that the labels for the agent and runconfig do not match. Agents can only pick up flows with matching labels. What are the labels for your agent here?

Hmm I found out that label called ‘jupyter-xxx’ is inserted when I am registering my flow… will try to figure out

You can add it to the storage.

flow.storage = Local(…, add_default_labels=False)

@Kevin Kho okay this maybe one last question. Now it founds agent, and it was successfully submitted. But it is infinitely stuck in submitted state. Any ideas..?

On Kubernetes, I think this means that it can’t get the hardware it needs to create the Flow

hey @Kevin Kho; I’ve run into the same issue. The docs were confusing on how to setup your local prefect cli to point to a Prefect Core Server instance. Fortunately I’ve found this thread here. Do you think the docs are out of date? • It mentions

[api]

- https://docs.prefect.io/core/concepts/configuration.html#extensions • It’s not clear if it’s something that a user needs to do on its prefect CLI installation or something to be done as part of server deployment - https://docs.prefect.io/orchestration/faq/config.html#connecting-to-a-different-api-endpoint

I don’t think it’s out of date because you can set HOST and PORT and it will combine to form ENDPOINT here. That API is on the server start up side to determine where to host the API

I’ve managed to set my configuration using the following

config.toml

file:

[server]
host_ip = "X.Y.Z.W"
host = "http://${server.host_ip}"
host_port = "4200"
endpoint = "${server.host}:${server.port}"

API link

that api config with host and url is not working for me though. But the server config is. I’m running prefect CLI version

0.15.13

prefect get flows                                                                                                                                                                                                 <aws:sdlc-admin>
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/urllib3/connection.py", line 169, in _new_conn
    conn = connection.create_connection(
  File "/usr/local/lib/python3.9/site-packages/urllib3/util/connection.py", line 96, in create_connection
    raise err
  File "/usr/local/lib/python3.9/site-packages/urllib3/util/connection.py", line 86, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [Errno 61] Connection refused

Did you use helm or the

prefect server start

?

the prefect server start

A couple of questions: 1. Are you trying to connect from a remote machine? If you are, you need to start with the

--expose

flag.

prefect server start --expose

2. Was starting successful? Can you go check if the GraphQL API is up on server?

yes the remote machine started the prefect server with the

--expose

flag. with my config.toml file on my mac I’m able to interact with the prefect server and register flows. I’m also able to use the graphql API to trigger flow runs

Nice! You good now? or did you mean you already did that but it didnt work?

yes. the way I did, with the config.toml file I’ve sent is working for me now. thank you for all the help 🙂

Thank you so much!