Added templates for common lambda functions

Author: Ben Fortuna

.gitignore

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+# Created by .ignore support plugin (hsz.mobi)
+terraform-aws-lambda-function.iml
+.terraform/

Makefile

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+SHELL:=/bin/bash
+TERRAFORM_VERSION=0.12.24
+TERRAFORM=docker run --rm -v "${PWD}:/work" -v "${HOME}:/root" -e AWS_DEFAULT_REGION=$(AWS_DEFAULT_REGION) -e http_proxy=$(http_proxy) --net=host -w /work hashicorp/terraform:$(TERRAFORM_VERSION)
+
+.PHONY: all clean test docs format
+
+all: test docs format
+
+clean:
+	rm -rf .terraform/
+
+test:
+	$(TERRAFORM) init && $(TERRAFORM) validate
+
+docs:
+	docker run --rm -v "${PWD}:/work" tmknom/terraform-docs markdown ./ >./README.md
+
+format:
+	$(TERRAFORM) fmt -list=true ./

README.md

@@ -1,2 +1,30 @@
-# terraform-aws-lambda-function
-Templates for common Lambda functions
+# ![AWS](aws-logo.png) Lambda Function
+
+Purpose: Provision a Lambda Function in AWS.
+
+Rationale: Apply standards provide templates for Lambda functions.
+
+## Requirements
+
+No requirements.
+
+## Providers
+
+| Name | Version |
+|------|---------|
+| archive | n/a |
+| aws | n/a |
+
+## Inputs
+
+| Name | Description | Type | Default | Required |
+|------|-------------|------|---------|:--------:|
+| function\_name | Name of the Lambda function | `any` | n/a | yes |
+| role | IAM role assumed by the Lambda function | `any` | n/a | yes |
+| runtime | A runtime to use for the function (leave blank to use default runtime) | `any` | `null` | no |
+| template | A predefined function template | `any` | n/a | yes |
+
+## Outputs
+
+No output.
+

aws-logo.png

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+locals {
+  templates = {
+    ec2-instance-cycle = {
+      lambda_handler  = "lambda_handler"
+      default_runtime = "python3.6"
+    }
+  }
+}

functions.tf

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+/**
+ * # ![AWS](aws-logo.png) Lambda Function
+ *
+ * Purpose: Provision a Lambda Function in AWS.
+ *
+ * Rationale: Apply standards provide templates for Lambda functions.
+ */
+data "archive_file" "function" {
+  source_dir  = "${path.module}/templates/${var.template}"
+  output_path = "${var.template}.zip"
+  type        = "zip"
+}
+
+data "aws_iam_role" "role" {
+  name = var.role
+}
+
+resource "aws_lambda_function" "function" {
+  function_name    = var.function_name
+  role             = data.aws_iam_role.role.arn
+  filename         = data.archive_file.function.output_path
+  handler          = "${var.function_name}.${local.templates[var.template]["lambda_handler"]}"
+  runtime          = var.runtime != null ? var.runtime : local.templates[var.template]["default_runtime"]
+  source_code_hash = data.archive_file.function.output_base64sha256
+}

main.tf

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+exports.handler = (event, context, callback) => {
+    const request = event.Records[0].cf.request;
+    request.uri = request.uri.replace(/\+/g, '%2B');
+    callback(null, request);
+};

templates/cloudfront-request-rewrite/handler.js

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+import re
+
+
+def lambda_handler(event):
+    request = event['Records'][0]['cf']['request']
+    request.uri = re.sub(r"\+", "%2B", request.uri)
+    return request

templates/cloudfront-request-rewrite/lambda_handler.py

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+"""
+DynamoDB Import Comma-separated values (CSV) document.
+
+An AWS Lambda function used to import batch records to a DynamoDB table.
+"""
+import csv
+import json
+import os
+import uuid
+
+import boto3
+from botocore.exceptions import ClientError
+
+data_types = os.environ['DataTypes']
+table_name = os.environ['TableName']
+item_template = json.loads(os.environ['ItemTemplate'])
+auto_generate_key = os.environ['AutoGenerateKey']
+
+
+def lambda_handler(event):
+    bucket = event['Records'][0]['s3']['bucket']['name']
+    filename = event['Records'][0]['s3']['object']['key']
+
+    import_file(bucket, filename)
+
+
+def import_file(bucket, filename):
+    s3 = boto3.client('s3')
+    dynamodb = boto3.client('dynamodb')
+    try:
+        data = s3.get_object(Bucket=bucket, Key=filename)['Body'].read().decode('utf-8')
+        csv_reader = csv.reader(data.splitlines(), delimiter=',')
+        columns = None
+        linenum = 0
+        for row in csv_reader:
+            if linenum == 0:
+                # use header row to identify the columns..
+                columns = row
+            else:
+                import_row(row2map(columns, row), dynamodb)
+            linenum += 1
+    except ClientError as e:
+        print(e)
+
+
+def row2map(columns, row):
+    retval = {}
+    if (auto_generate_key):
+        retval['UUID'] = uuid.uuid4().hex
+    for key, value in item_template.items():
+        data_type = data_types[key] if key in data_types else 'S'
+    retval[key] = {data_type: value}
+
+    for column in columns:
+        if len(row[columns.index(column)]) > 0:
+            data_type = data_types[column] if column in data_types else 'S'
+            retval[column] = {data_type: row[columns.index(column)]}
+    return retval
+
+
+def import_row(row, client):
+    try:
+        client.put_item(TableName=table_name, Item=row)
+    except ClientError as e:
+        print(e)

templates/dynamodb-table-import/lambda_handler.py

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+"""
+DynamoDB Put Item.
+
+An AWS Lambda function used to add items to a DynamoDB table.
+"""
+import json
+import os
+
+import boto3
+from botocore.exceptions import ClientError
+
+data_types = os.environ['DataTypes']
+table_name = os.environ['TableName']
+
+
+def lambda_handler(event):
+    item = json.loads(event['Item'])
+
+    put_item(dict2payload(item))
+
+
+def dict2payload(item):
+    retval = {}
+    for key, value in item.items():
+        data_type = data_types[key] if key in data_types else 'S'
+        retval[key] = {data_type: value}
+    return retval
+
+
+def put_item(payload):
+    dynamodb = boto3.client('dynamodb')
+    try:
+        dynamodb.put_item(TableName=table_name, Item=payload)
+    except ClientError as e:
+        print(e)