Merge pull request #7 from mozilla-services/feat/issue-4

feat: add lambda bundling and config

Makefile

@@ -2,7 +2,7 @@ SHELL := /bin/sh
 APPNAME = push_messages
 HERE = $(shell pwd)
 
-.PHONY: all travis $(HERE)/ddb
+.PHONY: all travis lambda-package
 
 all:	travis
 
@@ -12,3 +12,15 @@ travis: $(HERE)/ddb
 $(HERE)/ddb:
 	mkdir $@
 	curl -sSL http://dynamodb-local.s3-website-us-west-2.amazonaws.com/dynamodb_local_latest.tar.gz | tar xzvC $@
+
+$(HERE)/lenv:
+	virtualenv lenv
+	$(HERE)/lenv/bin/pip install -r lambda-requirements.txt
+	echo "#" > lenv/lib/python2.7/site-packages/zope/__init__.py
+	echo "#" > lenv/lib/python2.7/site-packages/repoze/__init__.py
+	echo "#" > lenv/lib/python2.7/site-packages/google/__init__.py
+	$(HERE)/lenv/bin/python setup.py develop
+
+lambda-package: $(HERE)/lenv
+	pip install lambda-uploader
+	$(HERE)/ppenv/bin/lambda-uploader --virtualenv=lenv --no-upload

README.md

@@ -24,3 +24,40 @@ Then:
     $ source ppenv/bin/activate
     $ pip install -r requirements.txt
     $ python setup.py develop
+
+## Creating an AWS Lambda Zipfile
+
+After modifying ``push_processor/settings.js`` for your appropriate settings, a
+Lambda-ready zipfile can be created with make:
+
+    $ make lambda-package
+
+All files in the work directory are included except files listed in the
+``ignore`` section of ``lambda.json``. Remove any other files that should not
+be included in the zipfile from the work directory.
+
+The AWS handler you should set is: ``lambda.handler``, which will then call
+the Push Processor.
+
+### Lambda VPC Access
+
+The Push Processor needs access to both Redis and AWS DynamoDB. It will
+likely be necessary to run the Lambda function in a VPC that has access to the
+Elasticache Redis instance. Lambda requires the subnet(s) it runs in to have
+NAT Gateway access to the Internet. A rough overview of what this looks like:
+
+![NAT Gateway](assets/NAT-access-to-Internet.png)
+
+1. Define one or more 'private' subnets, these are where your Lambda
+   function will run.
+2. Define one or more 'public' subnets, these are where the NAT Gateway(s) will
+   be.
+3. Create the NAT Gateway(s) in the 'public' subnets.
+4. Create a route table for the 'public' subnet(s), and route '0.0.0.0/0' to the
+   VPC Internet Gateway. The public subnets should then be explicitly associated
+   with the new route table.
+5. Create a route table for the 'private' subnet(s), and route '0.0.0.0/0' to a
+   NAT Gateway that you defined.
+
+The Push Processor Lambda function should then be able to access both DynamoDB
+and machines in the same 'private' subnet(s).

lambda-requirements.txt

@@ -0,0 +1,6 @@
+git+https://github.com/mozilla-services/push-messages.git@7cf9ea53141f124d8131d65ff7a1a7b32afef8e0#egg=push-messages
+boto3==1.2.6
+gzip_reader==0.1
+protobuf==2.6.1
+redis==2.10.5
+twisted==16.0.0

lambda.json

@@ -0,0 +1,20 @@
+{
+  "name": "PushProcessor",
+  "description": "Process Push Messages",
+  "region": "us-east-1",
+  "handler": "push_processor.handler.handler",
+  "role": "arn:aws:iam::00000000000:role/lambda_basic_execution",
+  "ignore": [
+    "circle.yml",
+    ".git",
+    "/*.pyc",
+    ".tox",
+    "ddb",
+    "ppenv",
+    "lenv",
+    "/*.txt",
+    "/*.json"
+  ],
+  "timeout": 30,
+  "memory": 128
+}

lambda.py

@@ -0,0 +1,3 @@
+from push_processor.handler import Lambda
+
+handler = Lambda.handler