Initial commit

Author: Vishal Parikh

.gitignore

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+vendor/*
+example/hello

Readme.md

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+
+# Wrap
+A very simple wrapper to wrap your [Labstack Echo ](https://github.com/labstack/echo) API's into Lambda/API Gateway
+
+### Installation
+```
+go get -u github.com/vdparikh/wrap
+go mod vendor
+```
+
+### Usage 
+Check out example/example.go for usage.
+
+```go
+package main
+
+import (
+	"github.com/aws/aws-lambda-go/lambda"
+	"github.com/labstack/echo"
+	"github.com/labstack/echo/middleware"
+	"github.com/vdparikh/wrap"
+)
+
+func main() {
+	e := echo.New()
+
+	e.Use(middleware.Logger())
+
+	e.GET("/hello", func(c echo.Context) error {
+		return c.JSON(200, "HELLO")
+	})
+
+	server := wrap.Route(e)
+
+	lambda.Start(server)
+}
+```
+
+### Run sample
+
+To run this locally as SAM (Serverless Application Model), then you need to install SAM CLI. SAM is an easier way to test out your serverless functions without having to deploy them first.
+- [AWS SAM CLI](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install-mac.html)
+
+```sh
+cd example
+# Build Binary
+GOARCH=amd64 GOOS=linux go build -ldflags="-s -w" -o hello .
+
+# Start SAM
+sam local start-api
+```
+
+On another terminal execute the API and you should see the HELLO response
+```sh
+curl -v http://localhost:3000/hello
+```

example/example.go

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+package main
+
+import (
+	"github.com/aws/aws-lambda-go/lambda"
+	"github.com/labstack/echo"
+	"github.com/labstack/echo/middleware"
+	"github.com/vdparikh/wrap"
+)
+
+func main() {
+	e := echo.New()
+
+	e.Use(middleware.Logger())
+
+	e.GET("/hello", func(c echo.Context) error {
+		return c.JSON(200, "HELLO")
+	})
+
+	server := wrap.Route(e)
+
+	lambda.Start(server)
+}

example/template.yaml

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+AWSTemplateFormatVersion : '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: AWS Data Lake Serverless Template
+
+Parameters:
+  Environment:
+    Type: String
+    Default: prod
+
+  StageName:
+    Type: String
+    Default: prod
+    Description: The Lambda Function and API Gateway Stage
+
+
+Globals:  
+  Function:
+    Runtime: go1.x
+    MemorySize: 512
+    Timeout: 30
+    Tags:
+      author: [email protected]
+
+  Api:
+    Cors:
+      AllowMethods: "'GET,POST,DELETE,PUT,OPTIONS'"
+      AllowHeaders: "'Authorization,authorization,DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range'"
+      AllowOrigin: "'*'"
+
+Resources:
+  ApiGateway:
+    Type: AWS::Serverless::Api
+    Properties:
+      StageName: Prod
+
+  HelloApi:
+    Type: AWS::Serverless::Function
+    Properties:
+      Handler: ./hello
+      Events:    
+        hello:
+          Type: Api
+          Properties:
+            Path: '/hello'
+            Method: get 
+            RestApiId: !Ref ApiGateway     

go.mod

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+module github.com/vdparikh/wrap
+
+go 1.12
+
+require (
+	github.com/aws/aws-lambda-go v1.9.0
+	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
+	github.com/labstack/echo v3.3.10+incompatible
+	github.com/labstack/gommon v0.2.8 // indirect
+	github.com/mattn/go-colorable v0.1.1 // indirect
+	github.com/mattn/go-isatty v0.0.7 // indirect
+	github.com/valyala/fasttemplate v1.0.1 // indirect
+	golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a // indirect
+)

go.sum

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+github.com/aws/aws-lambda-go v1.9.0 h1:r9TWtk8ozLYdMW+aelUeWny8z2mjghJCMx6/uUwOLNo=
+github.com/aws/aws-lambda-go v1.9.0/go.mod h1:zUsUQhAUjYzR8AuduJPCfhBuKWUaDbQiPOG+ouzmE1A=
+github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
+github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
+github.com/labstack/echo v3.3.10+incompatible h1:pGRcYk231ExFAyoAjAfD85kQzRJCRI8bbnE7CX5OEgg=
+github.com/labstack/echo v3.3.10+incompatible/go.mod h1:0INS7j/VjnFxD4E2wkz67b8cVwCLbBmJyDaka6Cmk1s=
+github.com/labstack/gommon v0.2.8 h1:JvRqmeZcfrHC5u6uVleB4NxxNbzx6gpbJiQknDbKQu0=
+github.com/labstack/gommon v0.2.8/go.mod h1:/tj9csK2iPSBvn+3NLM9e52usepMtrd5ilFYA+wQNJ4=
+github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
+github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
+github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.7 h1:UvyT9uN+3r7yLEYSlJsbQGdsaB/a0DlgWP3pql6iwOc=
+github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
+github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
+github.com/valyala/fasttemplate v1.0.1 h1:tY9CJiPnMXf1ERmG2EyK7gNUd+c6RKGD0IfU8WdUSz8=
+github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
+golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a h1:YX8ljsm6wXlHZO+aRz9Exqr0evNhKRNe5K/gi+zKh4U=
+golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223 h1:DH4skfRX4EBpamg7iV4ZlCpblAHI6s6TDM39bFZumv8=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

wrap.go

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+package wrap
+
+import (
+	"context"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+
+	"github.com/aws/aws-lambda-go/events"
+	"github.com/labstack/echo"
+)
+
+func formatAPIResponse(statusCode int, headers http.Header, responseData string) (events.APIGatewayProxyResponse, error) {
+	responseHeaders := make(map[string]string)
+
+	responseHeaders["Content-Type"] = "application/json"
+	for key, value := range headers {
+		responseHeaders[key] = ""
+
+		if len(value) > 0 {
+			responseHeaders[key] = value[0]
+		}
+	}
+
+	responseHeaders["Access-Control-Allow-Origin"] = "*"
+	responseHeaders["Access-Control-Allow-Headers"] = "origin,Accept,Authorization,Content-Type"
+
+	return events.APIGatewayProxyResponse{
+		Body:       responseData,
+		Headers:    responseHeaders,
+		StatusCode: statusCode,
+	}, nil
+}
+
+// Route wraps echo server into Lambda Handler
+func Route(e *echo.Echo) func(ctx context.Context, request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
+	return func(ctx context.Context, request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
+		body := strings.NewReader(request.Body)
+		req := httptest.NewRequest(request.HTTPMethod, request.Path, body)
+		for k, v := range request.Headers {
+			req.Header.Add(k, v)
+		}
+
+		q := req.URL.Query()
+		for k, v := range request.QueryStringParameters {
+			q.Add(k, v)
+		}
+		req.URL.RawQuery = q.Encode()
+
+		rec := httptest.NewRecorder()
+		e.ServeHTTP(rec, req)
+
+		res := rec.Result()
+		responseBody, err := ioutil.ReadAll(res.Body)
+		if err != nil {
+			return formatAPIResponse(http.StatusInternalServerError, res.Header, err.Error())
+		}
+
+		return formatAPIResponse(res.StatusCode, res.Header, string(responseBody))
+	}
+}