The document discusses AWS Lambda, a serverless computing service that shifts the processing model to event-based functions. It covers Lambda's invocation types, pricing structure, packaging of Python code, and scenarios for optimal usage, alongside practical examples. Key topics include function handlers, logging, and building packages with dependencies for executing Python Lambda functions.

1. Building Lambda Packages
In Python
Getting Past Hello World

2. Sponsors

3. Find me on LinkedIn
AWS Certifications
Presented by Adam Book

4. Lambda Uses
Using a serverless technology like AWS
Lambda takes a bit of shift in thinking
If you think about the quote from Werner Vogles:
“Everything fails all the time”
Then you might currently have an AutoScaling group of min 1 max 1 Desired 1
just for an instance that is processing a piece of data or doing a task on a daily or
scheduled basis.
Lambda may be the cost effective way to take over that event.

5. Lambda Uses
Using a serverless technology like AWS
Lambda takes a bit of shift in thinking
Event Based Processing
For more info
http://docs.aws.amazon.com/lambda/latest/dg/intro-core-components.html
AWS Services as Event Sources
S3 – Push Model
Dynamo DB – Pull Model
Kinesis – Pull Model
Simple Notification Service – Push Model
Amazon Cognito – Push Model
CloudWatchLogs - Push model
CloudWatch Events – Push Model
Scheduled Events (cloudwatch) – Push Model
AWS Config – Push model

6. Cascading Lambda Functions
One Lambda Events can be the triggering Event for another
Dynamo DB
redshift
S3

7. Ways to Invoke Lambda
Currently there are 2 ways to invoke Lambda
Event
This invocation type causes AWS Lambda to execute the Lambda function
asynchronously.
The event sources Amazon S3, Amazon SNS or Amazon DynamoDB use this
invocation type.
Request Response
This invocation type causes AWS Lambda to execute the function synchronously
and returns the response immediately to the calling application. This invocation
type is available for custom applications.

8. Cases where Lambda
isn’t a good fit
The AWS Certified Solutions Architect – Associate Level exam is
intended for individuals who perform a Solutions Architect role.
Scenario
The need for the latest OS patches and Security updates minutes or
hours after they’re released
The need to access the Security logs the host
The need to change the OS settings such as Memory Allocation or max
file handlers
An auditing and compliance requirement that requires you to take a
snapshot of a host after a security issue

9. Cases where Lambda
is a good Fit
The AWS Certified Solutions Architect – Associate Level exam is
intended for individuals who perform a Solutions Architect role.
Scenario
Automatically Tagging newly Created Instances
Automatically Shutting off
Performing Database functions such as bulk inserts and vacuums
Converting Bash Scripts which run automation tasks
Sending notifications to your Slack Channel

10. Lambda Pricing
AWS Lambda is one of the most Economical Services on AWS
Requests
• First 1 million requests per month are free
• $0.20 per 1 million requests thereafter ($0.0000002 per request)
If all of this sounds confusing then you might try this calculator found on
Matthew Fuller’s blog
For more info
https://aws.amazon.com/lambda/pricing/

11. Programming Model for
Lambda Functions in Python
In building your Python Lambda packages there are 4 main topics to
know :
• The Lambda Function Handler
• The Context Object
• Logging
• Exceptions
For more info
http://docs.aws.amazon.com/lambda/latest/dg/python-programming-model.html
NOTE: At the time of presentation you must
write your Python lambda code in 2.7

12. The Handler
The Handler is the function AWS Lambda calls to start execution of your Lambda
Function.
When a Lambda function is invoked then it starts executing your code by calling the
handler function.
It also passes any event data as the first parameter.
The Handler is the function AWS Lambda calls to start execution of
your Lambda Function.
For more info
http://docs.aws.amazon.com/lambda/latest/dg/programming-model-v2.html

13. The Handler
def lambda_handler(event, context):
myfile = retrieveFile(input_file, bucket)
newfile = converter(myfile,index,mytype)
return success
The Handler is the function AWS Lambda calls to start execution of
your Lambda Function.
For more info
http://docs.aws.amazon.com/lambda/latest/dg/programming-model-v2.html

14. Logging (in Python)
The following Python statements generate log entries:
• print statements.
• Logger functions in the logging module ( ie logging.Logger.info /
logging.Logger.errror)
Both print and logging.* function write logs to CloudWatch logs but the logging.*
functions write additional information to each log entry such as timestamp and log level.
The Handler is the function AWS Lambda calls to start execution of
your Lambda Function.
For more info
http://docs.aws.amazon.com/lambda/latest/dg/python-logging.html

15. Time to Test
Testing your Lambda
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16. Lambda Testing Checklist
Is the function timeout to low?
Does the function have the correct IAM Role and permissions for services that it’s
using and to send logs to Cloudwatch Logs?
Has the function been allocated enough memory?

17. Building the Package
Step 1 Start with a small / micro EC2 instance
running AWS linux
Once you’ve written your code (And Tested it) now you can build
your package with dependencies, zip it up and then upload.
NOTE: There’s other ways to build the package…this is the fastest
most effective way I’ve found for python

18. Building the Package
cont.
Step 2 SSH to your instance and create a directory for your Lambda code
NOTE: The name of the file doesn’t matter as much as the lambda
handler calling your other functions does.
Step 3 Move your code to that directory either via scp or by cutting and
pasting to a file with a .py extension
$mkdir /home/aws-user/cleaner_lambda

19. Building the Package
Adding Dependencies
Step 4 Install any libaries or dependencies that you need via pip directly to the
directory which you created.
NOTE: The name of the file doesn’t matter as much as the lambda
handler calling your other functions does.
$pip install requests –t /home/aws-user/cleaner_lambda

20. Building the Package
Creating the zip file
Step 5 Create the zip file and add NOT ONLY your python file but also the
directories of the packages which pip has downloaded for you
NOTE: using the –r flag will recursively add all the files in the
subsequent folders (in our case requests)
$zip –r lambda_cleanup.zip lambda_cleanup.py requests/

21. Python Lambda Packages
What about writing to files?
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22. Writing to files
def retrieveFile(filename, bucket):
s3conn = boto.connect_s3()
bucket = s3conn.get_bucket(bucket)
fn=filename
key = bucket.get_key(fn)
dl = key.get_contents_to_filename('/tmp/'+fn)
myfile = ("/tmp/"+fn)
return myfile
You can write to files (while processing) but you must do so in /tmp
After you have manipulated your file then you will need to save
somewhere else, most likely an S3 bucket

23. Which Packages don’t
need to be added
There are a handful of libraries that when imported do not need to
be built into a zip file.
• Boto / Boto3
• Time
• OS
For more info
http://docs.aws.amazon.com/lambda/latest/dg/python-programming-model.html

24. Python Lambda Packages
Real World Examples
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25. Python Lambda Packages
Real World Examples
A Cloudwatch to Slack Lambda Function
A Lambda Job to backup RDS instances
A Lambda Job that cleans S3 buckets
Word Analysis with Lambda
Nightly Shutdown (and startup) with Lambda

26. Lambda in other Flavors
Python 2.7 Java 8node.js 4.3
node.js 0.10

27. Questions?
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28. Interested in Sponsoring
AWS Atlanta?
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Contact us at
http://www.meetup.com/AWS-Atlanta/