@Marvin Ive got a block that requires oauth2 crendtials for a thirdparty api. Is there a recommend way to wrap the required get_token refresh_token functinoaklity in a task via httpx/starlette ?

To wrap OAuth2 credentials in a task for making HTTP requests in Prefect 2.x, you'll typically use the

httpx

library, which is a fully featured HTTP client for Python, and it's synchronous so you can easily use it within Prefect tasks. Here’s a general approach on how you could create a task to handle an OAuth2 flow: 1. Create a task that initiates the authorization process, requesting an access token from the OAuth2 provider. This usually involves sending client ID, client secret, and other required authorization details to a token URL. 2. Securely store OAuth2 credentials (like client ID and secret) using Prefect Secret blocks or the preferred secrets management of your choice. 3. Implement token refreshing logic within your task to handle scenarios where the token expires and necessitates a new one. 4. Make the actual API request with the acquired token included in the authorization header. Here is an outline of how you might define such a task:

python
import httpx
from prefect import flow, task
from prefect.blocks.system import Secret

@task(retries=2, retry_delay_seconds=5)
def get_oauth2_token(client_id: str, client_secret: str, token_url: str) -> str:
    # This is a simplification. You will need to add error handling and token refresh as needed.
    with httpx.Client() as client:
        response = <http://client.post|client.post>(token_url, data={
            'grant_type': 'client_credentials',
            'client_id': client_id,
            'client_secret': client_secret
        })
        response.raise_for_status()
        return response.json().get('access_token')

@task()
def make_authorized_request(url: str, token: str) -> dict:
    headers = {"Authorization": f"Bearer {token}"}
    
    with httpx.Client() as client:
        response = client.get(url, headers=headers)
        response.raise_for_status()
        return response.json()

@flow
def main_flow():
    client_id = Secret.load("api_client_id").get()
    client_secret = Secret.load("api_client_secret").get()
    token_url = "<https://provider.com/oauth2/token>"  # The OAuth token endpoint
    api_url = "<https://api.provider.com/data>"
    
    # Get the OAuth2 token
    token = get_oauth2_token(client_id, client_secret, token_url)
    
    # Make the authorized request
    data = make_authorized_request(api_url, token)

    # Do something with the data
    print(data)

# Run the flow
main_flow()

In this example, 'api_client_id' and 'api_client_secret' are stored as secrets (you should replace these with the actual secret names you use). The

get_oauth2_token

task would handle the initial retrieval of an OAuth2 token, which is then used by the

make_authorized_request

task when making requests to the API. This is the recommended way according to Prefect's task pattern, where you can split logic into reusable tasks and manage secrets securely. Always ensure to handle exceptions and to refresh tokens as needed based on the API provider’s documentation for token expiration.