Initial Commit

src/summarizer.py

@@ -0,0 +1,149 @@
+import os
+from datetime import datetime, timedelta
+from html.parser import HTMLParser
+from io import StringIO
+
+import requests
+from aws_lambda_powertools import Logger
+from aws_lambda_powertools.utilities import parameters
+from aws_lambda_powertools.utilities.typing import LambdaContext
+from langchain_core.messages import SystemMessage, HumanMessage
+from langchain_aws import ChatBedrockConverse
+from rss_parser import RSSParser
+from slack_sdk.webhook import WebhookClient
+
+from models import FeedItem, SlackMessage
+
+# Configurable
+MODEL = os.environ["BEDROCK_MODEL"]
+MAXLEN_DESCRIPTION = int(os.environ.get("MAXLEN_DESCRIPTION", "2500"))
+PARAM_SLACK_WEBHOOK = os.environ["PARAM_SLACK_WEBHOOK"]
+USER_AGENT = os.environ.get("USER_AGENT", "feedsummarizer 0.1 +harry@reeder.dev")
+
+# TODO: Make FEED_URL and SYSTEM_PROMPT configurable
+FEED_URL = "https://aws.amazon.com/about-aws/whats-new/recent/feed/"
+SYSTEM_PROMPT = """Using the following entries from the AWS "What's New" feed, create a once-per-week message to post to slack to keep people up to date with what they should know.
+
+Ensure that anything which is in preview is clearly marked as such.
+
+Categories should have relevant emoji, and individual entries should have a "Learn More" link to the article's page.
+"""
+
+LLM = ChatBedrockConverse(
+    model=MODEL,
+    temperature=0.5,
+    max_tokens=None,
+)
+
+SLACK_WEBHOOK_URL = parameters.get_parameter(PARAM_SLACK_WEBHOOK, decrypt=True)
+
+log = Logger()
+
+
+# From: https://stackoverflow.com/a/925630
+class MLStripper(HTMLParser):
+    def __init__(self):
+        super().__init__()
+        self.reset()
+        self.strict = False
+        self.convert_charrefs = True
+        self.text = StringIO()
+
+    def handle_data(self, d):
+        self.text.write(d)
+
+    def get_data(self):
+        return self.text.getvalue()
+
+
+def strip_tags(html: str) -> str:
+    s = MLStripper()
+    s.feed(html)
+    return s.get_data()
+
+
+def get_feed_entries(feed_url: str, since: int) -> list[FeedItem]:
+    response = requests.get(feed_url, headers={"User-Agent": USER_AGENT})
+    response_text = response.text
+    log.debug(
+        "got feed",
+        extra={
+            "feed_url": feed_url,
+            "response": {
+                "status_code": response.status_code,
+                "headers": dict(response.headers),
+            },
+        },
+    )
+    feed = RSSParser.parse(response_text)
+
+    items = [
+        FeedItem(
+            title=it.title.content,
+            description=strip_tags(it.description.content)[:MAXLEN_DESCRIPTION],
+            pub_date=it.pub_date.content,
+            link=it.links[0].content,
+        )
+        for it in feed.channel.items
+    ]
+
+    items = [it for it in items if it.timestamp > since]
+    oldest = min(items, key=lambda it: it.timestamp)
+
+    log.debug(
+        "filtered items",
+        extra={
+            "item_count": len(items),
+            "maxlen_description": MAXLEN_DESCRIPTION,
+            "oldest": oldest.pub_date,
+        },
+    )
+
+    return items
+
+
+def get_summary_message(feed_items: list[FeedItem]) -> SlackMessage:
+    messages = [
+        SystemMessage(SYSTEM_PROMPT),
+        HumanMessage("\n".join([it.model_dump_json() for it in feed_items])),
+    ]
+    model = LLM.with_structured_output(SlackMessage)
+    log.debug("invoking model", extra={"model": MODEL})
+    response = model.invoke(messages)
+    log.debug("got response")
+
+    return response
+
+
+def send_to_slack(message: SlackMessage):
+    client = WebhookClient(SLACK_WEBHOOK_URL)
+
+    for category in message.categories:
+        slack_message = f"{category.emoji} *{category.title}*"
+        for entry in category.entries:
+            slack_message += f"\n • {entry.headline} - <{entry.link}|Learn More>"
+
+        client.send(text=slack_message)
+
+
+def main():
+    if SLACK_WEBHOOK_URL == "not-set":
+        raise ValueError(
+            f"No Slack Webhook URL is currently set in SSM at {os.environ['PARAM_SLACK_WEBHOOK']}"
+        )
+
+    now = datetime.now()
+    last_week = now - timedelta(weeks=1)
+
+    entries = get_feed_entries(FEED_URL, since=int(last_week.timestamp()))
+    message = get_summary_message(entries)
+    send_to_slack(message)
+
+
+@log.inject_lambda_context
+def lambda_handler(event: dict, context: LambdaContext):
+    main()
+
+
+if __name__ == "__main__":
+    main()