diff options
| -rw-r--r-- | azure-pipelines.yml | 2 | ||||
| -rw-r--r-- | bot/cogs/reddit.py | 91 | ||||
| -rw-r--r-- | bot/constants.py | 2 | ||||
| -rw-r--r-- | config-default.yml | 2 | ||||
| -rw-r--r-- | docker-compose.yml | 2 |
5 files changed, 88 insertions, 11 deletions
diff --git a/azure-pipelines.yml b/azure-pipelines.yml index da3b06201..0400ac4d2 100644 --- a/azure-pipelines.yml +++ b/azure-pipelines.yml @@ -30,7 +30,7 @@ jobs: - script: python -m flake8 displayName: 'Run linter' - - script: BOT_API_KEY=foo BOT_TOKEN=bar WOLFRAM_API_KEY=baz coverage run -m xmlrunner + - script: BOT_API_KEY=foo BOT_TOKEN=bar WOLFRAM_API_KEY=baz REDDIT_CLIENT_ID=spam REDDIT_SECRET=ham coverage run -m xmlrunner displayName: Run tests - script: coverage report -m && coverage xml -o coverage.xml diff --git a/bot/cogs/reddit.py b/bot/cogs/reddit.py index bec316ae7..aa487f18e 100644 --- a/bot/cogs/reddit.py +++ b/bot/cogs/reddit.py @@ -2,9 +2,11 @@ import asyncio import logging import random import textwrap +from collections import namedtuple from datetime import datetime, timedelta from typing import List +from aiohttp import BasicAuth, ClientError from discord import Colour, Embed, TextChannel from discord.ext.commands import Cog, Context, group from discord.ext.tasks import loop @@ -17,25 +19,32 @@ from bot.pagination import LinePaginator log = logging.getLogger(__name__) +AccessToken = namedtuple("AccessToken", ["token", "expires_at"]) + class Reddit(Cog): """Track subreddit posts and show detailed statistics about them.""" - HEADERS = {"User-Agent": "Discord Bot: PythonDiscord (https://pythondiscord.com/)"} + HEADERS = {"User-Agent": "python3:python-discord/bot:1.0.0 (by /u/PythonDiscord)"} URL = "https://www.reddit.com" - MAX_FETCH_RETRIES = 3 + OAUTH_URL = "https://oauth.reddit.com" + MAX_RETRIES = 3 def __init__(self, bot: Bot): self.bot = bot - self.webhook = None # set in on_ready - bot.loop.create_task(self.init_reddit_ready()) + self.webhook = None + self.access_token = None + self.client_auth = BasicAuth(RedditConfig.client_id, RedditConfig.secret) + bot.loop.create_task(self.init_reddit_ready()) self.auto_poster_loop.start() def cog_unload(self) -> None: - """Stops the loops when the cog is unloaded.""" + """Stop the loop task and revoke the access token when the cog is unloaded.""" self.auto_poster_loop.cancel() + if self.access_token.expires_at < datetime.utcnow(): + self.revoke_access_token() async def init_reddit_ready(self) -> None: """Sets the reddit webhook when the cog is loaded.""" @@ -48,20 +57,82 @@ class Reddit(Cog): """Get the #reddit channel object from the bot's cache.""" return self.bot.get_channel(Channels.reddit) + async def get_access_token(self) -> None: + """ + Get a Reddit API OAuth2 access token and assign it to self.access_token. + + A token is valid for 1 hour. There will be MAX_RETRIES to get a token, after which the cog + will be unloaded and a ClientError raised if retrieval was still unsuccessful. + """ + for i in range(1, self.MAX_RETRIES + 1): + response = await self.bot.http_session.post( + url=f"{self.URL}/api/v1/access_token", + headers=self.HEADERS, + auth=self.client_auth, + data={ + "grant_type": "client_credentials", + "duration": "temporary" + } + ) + + if response.status == 200 and response.content_type == "application/json": + content = await response.json() + expiration = int(content["expires_in"]) - 60 # Subtract 1 minute for leeway. + self.access_token = AccessToken( + token=content["access_token"], + expires_at=datetime.utcnow() + timedelta(seconds=expiration) + ) + + log.debug(f"New token acquired; expires on {self.access_token.expires_at}") + return + else: + log.debug( + f"Failed to get an access token: " + f"status {response.status} & content type {response.content_type}; " + f"retrying ({i}/{self.MAX_RETRIES})" + ) + + await asyncio.sleep(3) + + self.bot.remove_cog(self.qualified_name) + raise ClientError("Authentication with the Reddit API failed. Unloading the cog.") + + async def revoke_access_token(self) -> None: + """ + Revoke the OAuth2 access token for the Reddit API. + + For security reasons, it's good practice to revoke the token when it's no longer being used. + """ + response = await self.bot.http_session.post( + url=f"{self.URL}/api/v1/revoke_token", + headers=self.HEADERS, + auth=self.client_auth, + data={ + "token": self.access_token.token, + "token_type_hint": "access_token" + } + ) + + if response.status == 204 and response.content_type == "application/json": + self.access_token = None + else: + log.warning(f"Unable to revoke access token: status {response.status}.") + async def fetch_posts(self, route: str, *, amount: int = 25, params: dict = None) -> List[dict]: """A helper method to fetch a certain amount of Reddit posts at a given route.""" # Reddit's JSON responses only provide 25 posts at most. if not 25 >= amount > 0: raise ValueError("Invalid amount of subreddit posts requested.") - if params is None: - params = {} + # Renew the token if necessary. + if not self.access_token or self.access_token.expires_at < datetime.utcnow(): + await self.get_access_token() - url = f"{self.URL}/{route}.json" - for _ in range(self.MAX_FETCH_RETRIES): + url = f"{self.OAUTH_URL}/{route}" + for _ in range(self.MAX_RETRIES): response = await self.bot.http_session.get( url=url, - headers=self.HEADERS, + headers={**self.HEADERS, "Authorization": f"bearer {self.access_token.token}"}, params=params ) if response.status == 200 and response.content_type == 'application/json': diff --git a/bot/constants.py b/bot/constants.py index 89504a2e0..ed85adf6a 100644 --- a/bot/constants.py +++ b/bot/constants.py @@ -465,6 +465,8 @@ class Reddit(metaclass=YAMLGetter): section = "reddit" subreddits: list + client_id: str + secret: str class Wolfram(metaclass=YAMLGetter): diff --git a/config-default.yml b/config-default.yml index 930a1a0e6..e6f0fda21 100644 --- a/config-default.yml +++ b/config-default.yml @@ -365,6 +365,8 @@ anti_malware: reddit: subreddits: - 'r/Python' + client_id: !ENV "REDDIT_CLIENT_ID" + secret: !ENV "REDDIT_SECRET" wolfram: diff --git a/docker-compose.yml b/docker-compose.yml index f79fdba58..7281c7953 100644 --- a/docker-compose.yml +++ b/docker-compose.yml @@ -42,3 +42,5 @@ services: environment: BOT_TOKEN: ${BOT_TOKEN} BOT_API_KEY: badbot13m0n8f570f942013fc818f234916ca531 + REDDIT_CLIENT_ID: ${REDDIT_CLIENT_ID} + REDDIT_SECRET: ${REDDIT_SECRET} |