retry.py

import logging
import requests
from requests.adapters import HTTPAdapter, Retry
from requests.exceptions import RetryError, HTTPError

# Configure basic logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

def call_api_with_retries():
    # Create a single Session
    session = requests.Session()

    # Configure retries for certain HTTP status codes or connection problems
    retries = Retry(
        total=3,                 # max retry attempts
        backoff_factor=0.1,      # sleep between attempts: 0.1s, 0.2s, 0.4s...
        status_forcelist=[500, 502, 503, 504],
        raise_on_status=False    # by default, don't raise automatically on 5xx
    )
    adapter = HTTPAdapter(max_retries=retries)
    session.mount("http://", adapter)
    session.mount("https://", adapter)

    # Example #1: URL that returns an HTTP 500
    # This will NOT raise RetryError if the connection succeeds but the server
    # keeps returning 500. Instead, you'll get a 5xx Response (response.ok = False).
    url_500 = "http://httpstat.us/500"

    # Example #2: URL that fails to connect (e.g., invalid port or hostname),
    # which typically leads to RetryError if it never succeeds.
    url_unreachable = "http://127.0.0.1:9999"

    try:
        logger.info("Sending request to %s", url_500)
        response = session.get(url_500)

        # If the server responded with 4xx/5xx, log "API call failed"
        if not response.ok:
            logger.error(
                "API call failed (status code: %s, reason: %s)",
                response.status_code,
                response.reason
            )
            # Optionally raise an exception:
            # response.raise_for_status()

    except RetryError as ex:
        # This block triggers if the retry logic fails entirely
        logger.exception("Max retries exhausted when calling %s", url_500)
        raise ex
    except HTTPError as ex:
        logger.exception("HTTP error occurred during request to %s", url_500)
        raise ex

    # Now illustrate unreachable URL => triggers RetryError if all attempts fail
    try:
        logger.info("Sending request to %s", url_unreachable)
        response = session.get(url_unreachable)
        # If no RetryError was raised, check the response
        if not response.ok:
            logger.error(
                "API call failed (status code: %s, reason: %s)",
                response.status_code,
                response.reason
            )
    except RetryError as ex:
        logger.exception("Max retries exhausted when calling %s", url_unreachable)
        raise ex
    except HTTPError as ex:
        logger.exception("HTTP error occurred during request to %s", url_unreachable)
        raise ex


if __name__ == "__main__":
    call_api_with_retries()