Commit zipped Lambda function into git

The Geodesic container does not contain pip, which is required to bundle the Python Lambda function dependencies into the zip archive. Rather than pulling pip into Geodesic and after discussion with @igor, it was deemed better to check in a zipped up archive of the Lambda function containing code and dependencies, and add a Make target to regenerate that, from within a Docker container. I’m not too fond of checking in binaries like zip files, as this is an extra manual step compared to the previous solution. If you change the function or dependencies, you need to remember to run `make build`

Author: joshmyers

.gitignore

@@ -1,7 +1,6 @@
 # Compiled files
 *.tfstate
 *.tfstate.backup
-*.zip
 
 # Module directory
 .terraform

Makefile

@@ -1,4 +1,6 @@
-SHELL := /bin/bash
+SHELL := /bin/bash
+LAMBDA_DIR := lambda
+DEPS_CONTAINER := alpine:3.8
 
 # List of targets the `readme` target should call before generating the readme
 export README_DEPS ?= docs/targets.md docs/terraform.md
@@ -7,4 +9,22 @@ export README_DEPS ?= docs/targets.md docs/terraform.md
 
 ## Lint terraform code
 lint:
-$(SELF) terraform/install terraform/get-modules terraform/get-plugins terraform/lint terraform/validate
+$(SELF) terraform/install terraform/get-modules terraform/get-plugins terraform/lint terraform/validate
+
+define docker
+docker run -it -v $(PWD)/$(LAMBDA_DIR)/:/code -w /code $(DEPS_CONTAINER) /bin/sh -c '$(1)'
+endef
+
+## Install dependencies
+dependencies:
+@echo "==> Installing Lambda function dependencies..."
+@$(call docker, apk add --update py-pip && \
+ pip install virtualenv && \
+ virtualenv venv --always-copy && \
+ source ./venv/bin/activate && \
+ ./venv/bin/pip install -qUr requirements.txt)
+
+## Build Lambda function zip
+build: dependencies
+@echo "==> Building Lambda function zip..."
+@cd $(LAMBDA_DIR) && zip -r ../elasticsearch_cleanup.zip * && cd ../

elasticsearch_cleanup.zip

@@ -23,13 +23,6 @@ data "aws_subnet_ids" "default" {
  vpc_id = "${var.vpc_id}"
 }
 
-data "archive_file" "default" {
- depends_on = ["null_resource.pip_install_deps"]
- type = "zip"
- source_dir = "${local.lambda_dir}"
- output_path = "${local.lambda_path}"
-}
-
 data "aws_iam_policy_document" "assume_role" {
  statement {
  actions = ["sts:AssumeRole"]
@@ -90,30 +83,13 @@ module "label" {
 # Locals
 #--------------------------------------------------------------
 locals {
- lambda_dir = "${path.module}/lambda"
- lambda_path = "${local.lambda_dir}/elasticsearch_cleanup.zip"
+ lambda_path = "${path.module}/elasticsearch_cleanup.zip"
  function_name = "${module.label.id}-elasticsearch-cleanup"
  enabled = "${var.enabled == "true" ? true : false }"
 }
 
 # Resources
 #--------------------------------------------------------------
-resource "null_resource" "pip_install_deps" {
- triggers {
- pip = "${base64sha256(file("${local.lambda_dir}/requirements.txt"))}"
- }
-
- provisioner "local-exec" {
- command = <<EOT
- cd "${local.lambda_dir}"
- pip install virtualenv
- virtualenv venv --always-copy
- source ./venv/bin/activate
- ./venv/bin/pip install -Ur requirements.txt
- EOT
- }
-}
-
 resource "aws_lambda_function" "default" {
  count = "${local.enabled == true ? 1 : 0}"
  filename = "${local.lambda_path}"
@@ -123,7 +99,7 @@ resource "aws_lambda_function" "default" {
  runtime = "python${var.python_version}"
  role = "${aws_iam_role.default.arn}"
  handler = "es-cleanup.lambda_handler"
- source_code_hash = "${data.archive_file.default.output_base64sha256}"
+ source_code_hash = "${base64sha256(file(local.lambda_path))}"
  tags = "${module.label.tags}"
 
  environment {