Add Lambda support

.gitignore

@@ -1,3 +1,4 @@
+.DS_Store
 .idea/
 info.log
 # Byte-compiled / optimized / DLL files

LAMBDA_README.md

@@ -0,0 +1,21 @@
+# Setting up Lambda
+There are 3 parts to configuring this to run as a Lambda
+1. IAM Role for Lambda - The IAM Role for you Lambda will have to give permissions for Lambda and Cost Explorer.
+2. Trigger - Event Bridge(Cloudwatch Alarms) setup with a cron expression to trigger a run daily.
+3. Function Code - You can directly paste in the get_forecast.py file is all ready to go.
+
+## IAM Role
+When you create the Lambda it will create a role for you with required Lambda permissions, you must add the following
+ permissions to it:
+![Lambda IAM Role](https://github.com/jimzucker/aws-forecast/blob/master/images/IAM_permissions.png)
+
+## Configuring Trigger
+Here is an example trigger, keep in mind the cron runs in UTC Timezone.
+![Lambda Trigger](https://github.com/jimzucker/aws-forecast/blob/master/images/event_bridge.png)
+
+## Function Code
+You can directly copy and paste get_forecast.py into the Lambda definition without modifications.
+![Lambda Function Code](https://github.com/jimzucker/aws-forecast/blob/master/images/lambda_function.png)
+
+# AWS Architecture
+![AWS Architecture](https://github.com/jimzucker/aws-forecast/blob/master/images/aws_architecture.png)

README.md

@@ -12,8 +12,7 @@ So I set out to automate this as a slack post daily to save time.  While doing t
 2. Application must produce a cleanly formatted one line output.
 3. Code must be written as python functions that we can re-use to integrate into a slack-bot.
 4. Post to slack if url is defined as an AWS secret (see below)
-
-# Technical Notes
+5. Provide example Lambda function that posts to slack on a cron 1 time per day
 
 ### Command line
 ```python3 get_forecast.py --profile <aws profile>  --type [FORECAST | ACTUALS]```
@@ -24,8 +23,21 @@ So I set out to automate this as a slack post daily to save time.  While doing t
 ### Enabling Slack
 To enable posting the message to slack instead of outputing to the command line you must define a secret in secrets manager called 'awsgenie_forecast_slack_url' with key=slack_url and value=<slack url>, if this secret is not found then the output is to the console.
 
-![Sample Output of get_forecast](https://github.com/jimzucker/aws-forecast/blob/master/images/aws_secret.png)
+![Enabling Slack](https://github.com/jimzucker/aws-forecast/blob/master/images/aws_secret.png)
+
+### Setting up Lambda
+There are 3 parts to configuring this to run as a Lambda
+1. IAM Role for Lambda - The IAM Role for you Lambda will have to give permissions for Lambda and Cost Explorer.
+2. Trigger - Event Bridge(Cloudwatch Alarms) setup with a cron expression to trigger a run daily.
+3. Function Code - You can directly paste in the get_forecast.py file is is all ready to go.
+
+[Click here for instructions for setting up Lambda](https://github.com/jimzucker/aws-forecast/blob/master/LAMBDA_README.md)
 
+# AWS Architecture
+![AWS Architecture](https://github.com/jimzucker/aws-forecast/blob/master/images/aws_architecture.png)
+
+
+# Technical Notes
 
 #### SSL Errors posting message to slack
 If you get SSL Cert errors defining this environment varialbe may help you:
@@ -43,6 +55,5 @@ In testing I found several situations where the calls to get_cost_forecast would
 2. Failure on new accounts or start of the month - on some days the calc fails due to insufficient data and we have to fall back to actuals
 
 # Backlog
-1. Add example Lambda function that posts to slack on a cron 1 time per day
-2. Deploy the whole thing as infrastructure as code with Cloud Formation
+1. Deploy the whole thing as infrastructure as code with Cloud Formation
 

get_forecast.py

@@ -36,16 +36,12 @@
 from urllib.request import Request, urlopen
 from urllib.error import URLError, HTTPError
 
-logging.basicConfig(
-    level=logging.INFO,
-    format="%(asctime)s [%(threadName)s] [%(levelname)s] %(message)s",
-    handlers=[
-        logging.FileHandler("info.log"),
-        logging.StreamHandler()
-    ])
+# Initialize you log configuration using the base class
+logging.basicConfig(level = logging.INFO)
 
+# Retrieve the logger instance
 logger = logging.getLogger()
-
+    
 
 def arg_parser():
     """Extracts various arguments from command line
@@ -75,6 +71,7 @@ def formatter(prog):
 
 def get_secret(client, secret_name):
     try:
+        text_secret_data = ""
         get_secret_value_response = client.get_secret_value(
             SecretId=secret_name
         )
@@ -208,8 +205,7 @@ def calc_forecast(costs_explorer_client):
 def display_output(forecast_slack_url,message):
     if forecast_slack_url != "":
         send_slack(forecast_slack_url, message)
-    else:
-        logger.info(message)
+    print(message)
 
 def send_slack(slack_hook_url, message):
     slack_message = {
@@ -227,29 +223,38 @@ def send_slack(slack_hook_url, message):
     except URLError as e:
         logger.error("Server connection failed: %s", e.reason)
 
-def get_forecast():
+def get_forecast(boto3_session, type):
+    print(boto3_session)
+    forecast_slack_url=""
+    try:
+        secrets_manager_client = boto3_session.client('secretsmanager')
+        forecast_slack_url='https://' + get_secret(secrets_manager_client, "awsgenie_forecast_slack_url")
+    except Exception as e:
+        logger.warning("Disabling Slack URL not found")
+        print(e)
+
+    costs_explorer_client = boto3_session.client('ce')
+    if type in ['FORECAST']:
+        forecast = calc_forecast(costs_explorer_client)
+        display_output(forecast_slack_url, forecast)
+    elif type in ['ACTUALS']:
+        raise Exception("not implimented - ACTUALS")
+        actuals = calc_forecast(costs_explorer_client)
+        display_output(forecast_slack_url, actuals)
+    else:
+        raise Exception("Invalid run type: cmdline_params.type . Please choose from: FORECAST, ACTUALS")
+
+    return forecast
+
+def lambda_handler(event, context):
+    logger.info("Event: " + str(event))
+    get_forecast(boto3, "FORECAST")
+
+def main():
     try:
         cmdline_params = arg_parser()
         boto3_session = boto3.Session(profile_name=cmdline_params.profile)
-        costs_explorer_client = boto3_session.client('ce')
-
-        forecast_slack_url=""
-        try:
-            secrets_manager_client = boto3_session.client('secretsmanager')
-            forecast_slack_url='https://' + get_secret(secrets_manager_client, "awsgenie_forecast_slack_url")
-        except Exception as e:
-            logger.warning("Disabling Slack URL not found")
-
-        if cmdline_params.type in ['FORECAST']:
-            forecast = calc_forecast(costs_explorer_client)
-            display_output(forecast_slack_url, forecast)
-        elif cmdline_params.type in ['ACTUALS']:
-            raise Exception("not implimented - ACTUALS")
-            actuals = calc_forecast(costs_explorer_client)
-            display_output(forecast_slack_url, actuals)
-        else:
-            print("Invalid run type: cmdline_params.type . Please choose from: FORECAST, ACTUALS")
-            sys.exit(1)
+        get_forecast(boto3_session, cmdline_params.type)
 
     except Exception as e:
         error_message = f"Error: {e}\n {traceback.format_exc()}"
@@ -259,4 +264,4 @@ def get_forecast():
     sys.exit(0)
 
 if __name__ == '__main__':
-    get_forecast()
+    main()