[Go] aws-sdk-go-v2 を使って SigV4 署名付きの HTTP リクエストを API Gateway に対して送信する

package main

import (
    "context"
    "fmt"
    "io/ioutil"
    "net/http"
    "time"

    v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
    "github.com/aws/aws-sdk-go-v2/config"
)

func main() {
    ctx := context.Background()

    cfg, err := config.LoadDefaultConfig(
        ctx,
        config.WithSharedConfigProfile("default"),
    )
    if err != nil {
        panic(err.Error())
    }

    credentials, err := cfg.Credentials.Retrieve(ctx)
    if err != nil {
        panic(err.Error())
    }

    req, err := http.NewRequest(
        http.MethodGet,
        "https://example.execute-api.ap-northeast-1.amazonaws.com/dummy-stage/dummy-endpoint",
        nil,
    )
    if err != nil {
        panic(err.Error())
    }

    hash := "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
    signer := v4.NewSigner()
    signer.SignHTTP(ctx, credentials, req, hash, "execute-api", "ap-northeast-1", time.Now())

    if err != nil {
        panic(err.Error())
    }

    httpClient := new(http.Client)

    response, err := httpClient.Do(req)
    if err != nil {
        panic(err.Error())
    }

    defer response.Body.Close()

    responseBody, err := ioutil.ReadAll(response.Body)
    if err != nil {
        panic(err.Error())
    }

    fmt.Print(string(responseBody))
}