''' OpenLambda's Python API '''

import json as pyjson

import requests

from requests import Session

class OpenLambda:

''' Represents a client connection to OpenLambda '''

def __init__(self, address="localhost:5000"):

self._address = address

self._session = Session()

def _post(self, path, data=None, timeout=None):

''' Issues a _post request to the OL worker '''

return self._session.post(f'http://{self._address}/{path}', pyjson.dumps(data), timeout=timeout)

def run(self, fn_name, args, json=True, timeout=60):

''' Execute a serverless function '''

resp = self._post(f"run/{fn_name}", args, timeout=timeout)

self._check_status_code(resp, "run")

if json:

return resp.json()

return resp.text

def create(self, args):

''' Create a new sandbox '''

resp = self._post("create", args)

self._check_status_code(resp, "create")

return resp.text.strip()

def destroy(self, sandbox_id):

''' Destroy a new sandbox '''

resp = self._post(f"destroy/{sandbox_id}", {})

self._check_status_code(resp, "destroy")

def pause(self, sandbox_id):

''' Pause a new sandbox '''

resp = self._post(f"pause/{sandbox_id}", None)

self._check_status_code(resp, "pause")

def get_statistics(self):

''' Returns stats of the OpenLambda server '''

resp = self._session.get(f"http://{self._address}/stats")

self._check_status_code(resp, "get_statistics")

return resp.json()

@staticmethod

def _check_status_code(resp, name):

if resp.status_code != 200:

msg = f'"{name}" failed with status code {resp.status_code}: {resp.text}'

raise requests.HTTPError(msg)

def check_status(self):

''' Checks the status of the OpenLambda server '''

resp = self._session.get(f"http://{self._address}/status")

self._check_status_code(resp, "check_status")