AWS Lambda deployment package maker

awslambda.mk

# Copyright (c) Productize
# This is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3
# as published by the Free Software Foundation.
# You can get the license at <http://www.gnu.org/licenses/gpl.html>
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# AWS Lambda deployment package maker
# 
# This makefile allows to easily create and upload AWS Lambda deployment packages.
#
# To use it, just create a `Makefile` and include this file.
# e.g: echo "include awslambda.mk" > Makefile
#
# It will automatically search for Python modules installed by pip and add them
# to the zip file uploaded to AWS Lambda based on the requirements.txt file.
#
# The Sha256 checksum of the zip file is calculated so up-to-date zip files
# are not sent unnecessarily.
#
# Notes:
#  - Using requirements with a required version is not (yet) supported.
#  - Removing a source file or requirement will not cause it to be removed
#    from the zip file. Use `make clean` if this is a problem.
#
# Dependencies:
#  - Zip (Duh): e.g http://www.info-zip.org/Zip.html
#  - GNU make (obviously): https://www.gnu.org/software/make/
#  - AWS cli: https://aws.amazon.com/cli/
#  - jq (to parse results from aws cli): https://stedolan.github.io/jq/
#  - pip (to find the location of packages and install missing ones):
#    https://pypi.python.org/pypi/pip
#  - OpenSSL toolkit (for calculating checksums): https://www.openssl.org/

FN=$(shell cat configuration.json | jq -r '.["FunctionName"]')
WD=$(shell pwd)
SRC=$(shell find src -type f)
REQUIREMENTS=$(shell if [ -a requirements.txt ]; then echo requirements.zip; fi;)

define get_package_location
$(shell pip show $1 | while read -r line; do \
	if [ "$${line% *}" = "Location:" ]; then \
		echo $${line#* }; \
	fi; \
done;)
endef

all: $(FN).zip

clean:
	rm -f requirements.zip
	rm -f $(FN).zip

# Put required packages in zip file
requirements.zip: requirements.txt
	@echo "Adding required modules"
	@rm -f requirements.zip
	@while read -r req; do \
		pkg_info=`pip show $$req`; \
		if [ "$$pkg_info" = "" ]; then \
			echo "Requirement $$req not found"; \
			read -p 'Do you want to install it (pip install '$$req')? [Y/n]: ' continue </dev/tty; \
			if [ "$$continue" = "N" ] || [ "$$continue" = "n" ]; then \
				continue; \
			else \
				pip install $$req; \
				pkg_info=`pip show $$req`; \
			fi; \
		fi; \
		echo "$$pkg_info" | while read -r line; do \
			if [ "$${line% *}" = "Location:" ]; then \
				cd $${line#* }; \
				zip -r $(WD)/requirements.zip $$req; \
			fi; \
		done; \
	done < requirements.txt

$(FN).zip: $(REQUIREMENTS) $(SRC)
	@echo "Adding sources"
	@if [ -a requirements.zip ]; then \
		cp requirements.zip $(FN).zip; \
	fi;
	@cd src; zip -r -x="*.pyc" $(WD)/$(FN).zip *
	@echo "Created $(FN).zip"

upload: $(FN).zip
	@ \
	local_dgst=`cat $(FN).zip | \
		openssl dgst -sha256 -binary | \
		openssl base64`; \
	remote_dgst=`aws lambda get-function --output json --function-name $(FN) | \
		jq -r '.["Configuration"]["CodeSha256"]'`; \
	if [ "$$local_dgst" != "$$remote_dgst" ]; then \
		echo "Updating Lambda function"; \
		aws lambda update-function-code \
			--function-name $(FN) \
			--zip-file fileb://$(FN).zip; \
	else \
		echo "Lambda function is up-to-date"; \
	fi;

.PHONY: upload