Lambda for mail Notification

Resume

Takes a payload triggered from Cloud Watch logs, parse it in to a HTML table and sends over mail with Amazon SES.

In this case the event messages are in xml and will be converted to json for better manipulation.

Requesites

1 - Cloud Watch Log Group receiving events in XML 2 - Lambda Trigger configured for Cloud Watch logs from specific group with optional filters 3 - Validated e-mail in Amazon Simple E-mail Service 4 - This project folder as a zip file to deploy the lambda code and libraries

Deploy

To deploy this lambda, create a zip file with the files lambda_function.py and xmltodict.py.

In AWS CONSOLE

Create a lambda with Python 3.7 runtime.

UPLOAD THE CODE

Click in upload and choose the zip file with our python code and send it.

CREATE THE TRIGGER

In the lambda designer, click on ADD TRIGGER and select Cloud Watch Logs, Log Group and create a filter as the example image or as you want.

After this, click in ADD

With CLOUD FORMATION

• Create a S3 bucket ant upload the zip file with lambda's code
• Go to Aws Console and access cloud formation service
• Create a new stack and upload the cloudformation.yml file
• See the Magic

How It works

• The Lambda receives the event message from cloud watch, decrypt and unconpress it.
• Takes the json payload and access the key logEvents
• Converts the log events in XML to json and appends it to a variable called message as a json dump.
• the variable filtro receives a list of Keys to be searched in the events, filtering which information should be inserted in the Html table. Leave empty to get all event fields available.
• For each event, lambdas generates a header with the keys and a line with the respective values. After get all events, concatenate the complete table in a variable.
• The sender, recipient, Subject, Html Body and AWS region are assigned into variables. *Customize as you wish*.
• The boto3 library is called to interact with amazon SES and assemble the e-mail and try to send it. If There is an error, it should be shown in the console. If thats all right, you should see a message saying E-mail Sent!

How to Test it

Create a Test Event

You can create a lambda test by clicking in CONFIGURE TEST EVENTS as shown in the example image

In the next screen click in create new test as bellow.

You can copy an example in the test.txt file and put it's contents in aws console respective field.

Mail Notification example