]> git.cworth.org Git - turbot/blobdiff - turbot_lambda/turbot_lambda.py
Some style fixes pointed out by flake8
[turbot] / turbot_lambda / turbot_lambda.py
index f3d28f25f7abb6a0afde786d246c0c1ff29ee93c..80cc4d27a26bee30c7a8fbde7c90ecb80b88f541 100644 (file)
 from urllib.parse import parse_qs
-from turbot.rot import rot
+from slack import WebClient
+import base64
+import boto3
+import requests
+import json
+import os
+import pickle
+from types import SimpleNamespace
+from google.auth.transport.requests import Request
+from googleapiclient.discovery import build
+
+import turbot.actions
+import turbot.commands
+import turbot.events
+
+ssm = boto3.client('ssm')
+
+response = ssm.get_parameter(Name='SLACK_SIGNING_SECRET', WithDecryption=True)
+slack_signing_secret = response['Parameter']['Value']
+os.environ['SLACK_SIGNING_SECRET'] = slack_signing_secret
+
+# Note: Late import here to have the environment variable above available
+from turbot.slack import slack_is_valid_request # noqa
+
+response = ssm.get_parameter(Name='SLACK_BOT_TOKEN', WithDecryption=True)
+slack_bot_token = response['Parameter']['Value']
+slack_client = WebClient(slack_bot_token)
+
+response = ssm.get_parameter(Name='GSHEETS_PICKLE_BASE64', WithDecryption=True)
+gsheets_pickle_base64 = response['Parameter']['Value']
+gsheets_pickle = base64.b64decode(gsheets_pickle_base64)
+gsheets_creds = pickle.loads(gsheets_pickle)
+if gsheets_creds:
+    if gsheets_creds.valid:
+        print("Loaded valid GSheets credentials from SSM")
+    else:
+        gsheets_creds.refresh(Request())
+        gsheets_pickle = pickle.dumps(gsheets_creds)
+        gsheets_pickle_base64 = base64.b64encode(gsheets_pickle)
+        print("Storing refreshed GSheets credentials into SSM")
+        ssm.put_parameter(Name='GSHEETS_PICKLE_BASE64',
+                          Type='SecureString',
+                          Value=str(gsheets_pickle_base64),
+                          Overwrite=True)
+service = build('sheets',
+                'v4',
+                credentials=gsheets_creds,
+                cache_discovery=False)
+sheets = service.spreadsheets()
+
+db = boto3.resource('dynamodb')
+
+turb = SimpleNamespace()
+turb.slack_client = slack_client
+turb.db = db
+turb.sheets = sheets
+
+def error(message):
+    """Generate an error response for a Slack request
+
+    This will print the error message (so that it appears in CloudWatch
+    logs) and will then return a dictionary suitable for returning
+    as an error response."""
+
+    print("Error: {}.".format(message))
+
+    return {
+        'statusCode': 400,
+        'body': ''
+    }
 
 def turbot_lambda(event, context):
     """Top-level entry point for our lambda function.
 
-    Currently only calls into the rot() function but may become more
-    sophisticated later on."""
+    This function first verifies that the request actually came from
+    Slack, (by means of the SLACK_SIGNING_SECRET SSM parameter), and
+    refuses to do anything if not.
 
-    body = parse_qs(event['body'])
-    result = rot(body['text'][0])
+    Then this defers to either turbot_event_handler or
+    turbot_slash_command to do any real work.
+    """
+
+    headers = requests.structures.CaseInsensitiveDict(event['headers'])
+
+    signature = headers['X-Slack-Signature']
+    timestamp = headers['X-Slack-Request-Timestamp']
+
+    if not slack_is_valid_request(signature, timestamp, event['body']):
+        return error("Invalid Slack signature")
+
+    # It's a bit cheesy, but we'll just use the content-type header to
+    # determine if we're being called from a Slack event or from a
+    # slash command or other interactivity. (The more typical way to
+    # do this would be to have different URLs for each Slack entry
+    # point, but it's simpler to have our Slack app implemented as a
+    # single AWS Lambda, (which can only have a single entry point).
+    content_type = headers['content-type']
+
+    if (content_type == "application/json"):
+        return turbot_event_handler(turb, event, context)
+    if (content_type == "application/x-www-form-urlencoded"):
+        return turbot_interactive_or_slash_command(turb, event, context)
+    return error("Unknown content-type: {}".format(content_type))
+
+def turbot_event_handler(turb, event, context):
+    """Handler for all subscribed Slack events"""
+
+    body = json.loads(event['body'])
+
+    type = body['type']
+
+    if type == 'url_verification':
+        return url_verification_handler(turb, body)
+    if type == 'event_callback':
+        return event_callback_handler(turb, body)
+    return error("Unknown event type: {}".format(type))
+
+def url_verification_handler(turb, body):
+
+    # First, we have to properly respond to url_verification
+    # challenges or else Slack won't let us configure our URL as an
+    # event handler.
+    challenge = body['challenge']
 
     return {
         'statusCode': 200,
-        'body': result
+        'body': challenge
     }
+
+def event_callback_handler(turb, body):
+    type = body['event']['type']
+
+    if type in turbot.events.events:
+        return turbot.events.events[type](turb, body)
+    return error("Unknown event type: {}".format(type))
+
+def turbot_interactive_or_slash_command(turb, event, context):
+    """Handler for Slack interactive things (buttons, shortcuts, etc.)
+    as well as slash commands.
+
+    This function simply makes a quiuck determination of what we're looking
+    at and then defers to either turbot_interactive or turbot_slash_command."""
+
+    # Both interactives and slash commands have a urlencoded body
+    body = parse_qs(event['body'])
+
+    # The difference is that an interactive thingy has a 'payload'
+    # while a slash command has a 'command'
+    if 'payload' in body:
+        return turbot_interactive(turb, json.loads(body['payload'][0]))
+    if 'command' in body:
+        return turbot_slash_command(turb, body)
+    return error("Unrecognized event (neither interactive nor slash command)")
+
+def turbot_interactive(turb, payload):
+    """Handler for Slack interactive requests
+
+    These are the things that come from a user interacting with a button
+    a shortcut or some other interactive element that our app has made
+    available to the user."""
+
+    type = payload['type']
+
+    if type == 'block_actions':
+        return turbot_block_action(turb, payload)
+    if type == 'view_submission':
+        return turbot.actions.view_submission(turb, payload)
+    return error("Unrecognized interactive type: {}".format(type))
+
+def turbot_block_action(turb, payload):
+    """Handler for Slack interactive block actions
+
+    Specifically, those that have a payload type of 'block_actions'"""
+
+    actions = payload['actions']
+
+    if len(actions) != 1:
+        return error("No support for multiple actions ({}) in a single request"
+                     .format(len(actions)))
+
+    action = actions[0]
+
+    atype = action['type']
+    avalue = action['value']
+
+    if (
+            atype in turbot.actions.actions
+            and avalue in turbot.actions.actions[atype]
+    ):
+        return turbot.actions.actions[atype][avalue](turb, payload)
+    return error("Unknown action of type/value: {}/{}".format(atype, avalue))
+
+def turbot_slash_command(turb, body):
+    """Implementation for Slack slash commands.
+
+    This parses the request and arguments and farms out to
+    supporting functions to implement all supported slash commands.
+    """
+
+    command = body['command'][0]
+    args = body['text'][0]
+
+    if command in turbot.commands.commands:
+        return turbot.commands.commands[command](turb, body, args)
+
+    return error("Command {} not implemented".format(command))