Go言語で作ったLambda関数にて，API Gateway経由でJSON形式の入力を受け取る処理のベース部分の作りについてメモ
環境
- MacOS Mojave
- Go 1.11.5
- Serverless Framework 1.37.1
プロジェクト作成
- $GOHOME/src配下の任意フォルダで作業
helloとworldの2つの関数(+API)を持つテンプレートが展開される
1$ sls create -t aws-go-dep -p <project-name>
serverless.ymlにregionを追記 +helloのメソッドをPOSTに変更
1provider:
2 name: aws
3 runtime: go1.x
4 region: ap-northeast-1
5...
6functions:
7 hello:
8 handler: bin/hello
9 events:
10 - http:
11 path: wake-up
12 method: post
13...
関数修正
hello側だけ修正してみる- リクエストのbodyにあるJSONを受け，得られた値を含む文字列を返すよう修正
1package main
2
3import (
4 "bytes"
5 "context"
6 "encoding/json"
7 "fmt"
8
9 "github.com/aws/aws-lambda-go/events"
10 "github.com/aws/aws-lambda-go/lambda"
11)
12
13// Response is of type APIGatewayProxyResponse since we're leveraging the
14// AWS Lambda Proxy Request functionality (default behavior)
15//
16// https://serverless.com/framework/docs/providers/aws/events/apigateway/#lambda-proxy-integration
17type Response events.APIGatewayProxyResponse
18
19// InputBody is struct for body contents in api request
20type InputBody struct {
21 Test string `json:"test"`
22}
23
24// Handler is our lambda handler invoked by the `lambda.Start` function call
25func Handler(ctx context.Context, request events.APIGatewayProxyRequest) (Response, error) {
26 var buf bytes.Buffer
27
28 // parse request.Body and create InputBody
29 var ib InputBody
30 var err = json.Unmarshal([]byte(request.Body), &ib)
31 if err != nil {
32 var em = "Error in parsing input body json"
33 fmt.Println(em)
34 resp := Response{
35 StatusCode: 400,
36 Body: em,
37 }
38 return resp, err
39 }
40
41 // if parsed, create return message
42 var msg = "input is " + ib.Test
43 body, err := json.Marshal(map[string]interface{}{
44 "message": msg,
45 })
46 if err != nil {
47 return Response{StatusCode: 404}, err
48 }
49 json.HTMLEscape(&buf, body)
50
51 resp := Response{
52 StatusCode: 200,
53 IsBase64Encoded: false,
54 Body: buf.String(),
55 Headers: map[string]string{
56 "Content-Type": "application/json",
57 "X-MyCompany-Func-Reply": "hello-handler",
58 },
59 }
60
61 return resp, nil
62}
63
64func main() {
65 lambda.Start(Handler)
66}
67
68
補足
- Go言語でJSONを受けるには以下の手順が必要
- 想定入力のデータ構造をstructで定義
- 結果をstruct変数を用意
- request.Body配下の(JSON形式の)文字列をパース (Unmarshal)
デプロイ
- 以下でデプロイ
make deploy=make+sls deploy
1$ cd <project-name>
2$ make deploy
- 出力メッセージ中にあるURLに
curlやPostmanでアクセス
Tagged: #lambda #serverless framework #Go #API Gateway