initial check-in of aws-api-to-lambda-shim

Author: Dana H. P'Simer, Jr

.gitignore

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+# Created by .ignore support plugin (hsz.mobi)
+### Go template
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+
+*.zip
+.idea
+
+examples/helloWorld/helloWorld

Readme.md

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+# AWS Lambda HTTP Handler Shim
+
+This software is based, in part, on the work done by [eawsy](http://github.com/eawsy/aws-lambda-go/) 
+ Their terrific idea was to use the Python 2.7 runtime available in [AWS Lamnda](https://aws.amazon.com/lambda/)
+ to run [go](http://golang.com) programs.  I was in the midst of creating a new API using [goa](http://goa.design)
+ and it dawned on me that if I could somehow trick goa into responding to [AWS Api Gateway](https://aws.amazon.com/api-gateway/)
+ I could have a service that could both run standalone and serverless on API Gateway and Lambnda.
+
+So I created this.
+
+## Usage
+
+For complete details checkout the [helloWorld example](examples/helloWorld)
+
+The basic steps for usage are as follows:
+
+1. separate your configuration of your web service muxer from your call to
+ http.ListenAndServe.
+```golang
+package hello
+
+import (
+  "net/http"
+  ...
+)
+
+
+func InitHandler() (http.Handler, error) {
+  mux := http.NewServeMux()
+  mux.HandleFunc("/hello/", func(w http.ResponseWriter, req *http.Request) {
+    ...
+  })
+  return mux, nil
+}
+```
+2. Create your main() for your web service:
+```go
+package main
+
+import (
+	"github.com/danapsimer/aws-lambda-shim/examples/helloWorld/hello"
+	"log"
+	"net/http"
+)
+
+func main() {
+	handler, _ := hello.InitHandler()
+	log.Fatal(http.ListenAndServe(":8080", handler))
+}
+```
+3. create your main() for your lambda:
+```go
+package main
+
+import (
+	"github.com/danapsimer/aws-lambda-shim/examples/helloWorld/hello"
+	"github.com/danapsimer/aws-lambda-shim/shim"
+)
+
+func init() {
+	shim.NewHttpHandlerShim(hello.InitHandler)
+}
+
+func main() {
+}
+```
+4. Make your lambda:
+```Makefile
+build:
+	go build -buildmode=c-shared -ldflags="-w -s" -o handler.so
+	chown `stat -c "%u:%g" .` handler.so
+
+pack:
+	zip handler.zip handler.so
+	chown `stat -c "%u:%g" .` handler.zip
+```
+5. Create your lambda in AWS: (in the directory your lambda handler was built)
+```sh
+aws lambda create-function \
+    --function-name hello-world-api \
+    --runtime python2.7 --handler handler.handle --zip-file fileb://handler.zip \
+    --role arn:aws:iam::${AWS_ACCOUNT_ID}:role/lambda_basic_execution
+```
+6. Create your API Gateway API:
+```sh
+aws apigateway import-rest-api \
+  --body file://examples/helloWorld/swagger.json --region us-east-1
+aws lambda add-permission --region us-east-1 \
+  --function-name hello-world-api --statement-id 5 \
+  --principal apigateway.amazonaws.com --action lambda:InvokeFunction \
+  --source-arn 'arn:aws:execute-api:us-east-1:${AWS_ACCOUNT_ID}:3l3za8xwnd/*/*/*'
+```
+**NOTE:** you need to replace the '*${AWS_ACCOUNT_ID}*' place holder in 
+ the swagger.json and the aws commands above with your account id.
+ 

examples/helloWorld/Readme.md

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+# Hello World Example for aws-lambda-shim
+
+This directory contains a simple "Hello, World" webservice that can be
+ deployed to either AWS Lambda and accessed through AWS Api Gateway or
+ run standalone as a traditional go HTTP server.

examples/helloWorld/hello/hello.go

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+package hello
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"regexp"
+)
+
+var (
+	helloMatcher = regexp.MustCompile("/hello/(.*)")
+)
+
+type greeting struct {
+	Greeting string `json:"greeting,omitempty"`
+}
+
+func InitHandler() (http.Handler, error) {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/hello/", func(w http.ResponseWriter, req *http.Request) {
+		matches := helloMatcher.FindAllStringSubmatch(req.URL.Path, -1)
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		name := matches[0][1]
+		if name == "" {
+			name = "World"
+		}
+		greeting := greeting{fmt.Sprintf("Hello, %s!", name)}
+		jsonEncoder := json.NewEncoder(w)
+		jsonEncoder.Encode(greeting)
+	})
+	return mux, nil
+}

examples/helloWorld/lambda/Makefile

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+# System build
+
+build:
+	go build -buildmode=c-shared -ldflags="-w -s" -o handler.so
+	chown `stat -c "%u:%g" .` handler.so
+
+pack:
+	zip handler.zip handler.so
+	chown `stat -c "%u:%g" .` handler.zip
+
+# Docker build for OS X or Windoze
+
+dbuild:
+	@docker run --rm \
+		-v $(GOPATH):/go \
+		-w /go/src/github.com/danapsimer/aws-lambda-shim/examples/helloWorld/lambda \
+		eawsy/aws-lambda-go make build
+
+dpack:
+	@docker run --rm \
+		-v $(GOPATH):/go \
+		-w /go/src/github.com/danapsimer/aws-lambda-shim/examples/helloWorld/lambda \
+		eawsy/aws-lambda-go make pack
+
+clean:
+	@rm -rf handler.zip handler.so
+
+deploy:
+	@aws lambda update-function-code --function-name hello-world-api --zip-file fileb://handler.zip

examples/helloWorld/lambda/handler.go

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+package main
+
+import (
+	"github.com/danapsimer/aws-api-to-lambda-shim/examples/helloWorld/hello"
+	"github.com/danapsimer/aws-api-to-lambda-shim/shim"
+)
+
+func init() {
+	shim.NewHttpHandlerShim(hello.InitHandler)
+}
+
+func main() {
+}

examples/helloWorld/main.go

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+package main
+
+import (
+	"github.com/danapsimer/aws-api-to-lambda-shim/examples/helloWorld/hello"
+	"log"
+	"net/http"
+)
+
+func main() {
+	handler, _ := hello.InitHandler()
+	log.Fatal(http.ListenAndServe(":8080", handler))
+}

examples/helloWorld/swagger.json

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+{
+  "swagger": "2.0",
+  "info": {
+    "version": "2016-09-12T17:50:37Z",
+    "title": "HelloWorldLambdaProxyIntegration"
+  },
+  "basePath": "/hello",
+  "schemes": [
+    "https"
+  ],
+  "paths": {
+    "/{proxy+}": {
+      "x-amazon-apigateway-any-method": {
+        "produces": [
+          "application/json"
+        ],
+        "parameters": [
+          {
+            "name": "proxy",
+            "in": "path",
+            "required": true,
+            "type": "string"
+          }
+        ],
+        "responses": {},
+        "x-amazon-apigateway-integration": {
+          "uri": "arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:${AWS_ACCOUNT_ID}:function:hello-world-api/invocations",
+          "passthroughBehavior": "when_no_match",
+          "httpMethod": "POST",
+          "type": "aws_proxy"
+        }
+      }
+    }
+  }
+}