Google App Engine Go 1.11 应用程序无法访问 Google Spreadsheets

我正在尝试通过 API 从运行的应用程序访问谷歌电子表格Google App Engine Go 1.11 标准环境 https://cloud.google.com/appengine/docs/standard/go111/。 不幸的是，应用程序无法读取这个电子表格 https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit.

我收到下一个错误Spreadsheets.Values.Get https://godoc.org/google.golang.org/api/sheets/v4#SpreadsheetsValuesService.Get call:

googleapi: Error 403: Request had insufficient authentication scopes., forbidden

示例代码

// Sample app showing issue with GAE -> google spreadsheets
package main

import (
    "context"
    "fmt"
    "log"
    "net/http"
    "os"

    "cloud.google.com/go/compute/metadata"
    "golang.org/x/oauth2/google"
    "google.golang.org/api/sheets/v4"
)

func main() {
    http.HandleFunc("/", indexHandler)

    // [START setting_port]
    port := os.Getenv("PORT")
    if port == "" {
        port = "8080"
        log.Printf("Defaulting to port %s\n", port)
    }

    // let's check app engine instance scopes
    scopes, _ := metadata.Get("instance/service-accounts/default/scopes")
    log.Printf("[DEBUG] metadata scopes: %s.\n", scopes)

    log.Printf("Listening on port %s", port)
    log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
    // [END setting_port]
}

// indexHandler responds to requests with our greeting.
func indexHandler(w http.ResponseWriter, r *http.Request) {
    ctx := context.Background()
    client, _ := google.DefaultClient(ctx, "https://www.googleapis.com/auth/spreadsheets.readonly")
    srv, err := sheets.New(client)

    // Prints the names and majors of students in a sample spreadsheet:
    // https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit
    spreadsheetId := "1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms"
    readRange := "Class Data!A2:E"
    resp, err := srv.Spreadsheets.Values.Get(spreadsheetId, readRange).Do()
    if err != nil {
        log.Fatalf("Unable to retrieve data from sheet: %v\n", err)
    }

    if len(resp.Values) == 0 {
        fmt.Fprintf(w, "No data found.\n")
    } else {
        fmt.Fprintf(w, "Name, Major:\n")
        for _, row := range resp.Values {
            // Print columns A and E, which correspond to indices 0 and 4.
            fmt.Fprintf(w, "%s, %s\n", row[0], row[4])
        }
    }

}

重现步骤：

1）部署应用程序：gcloud app deploy
2）在浏览器中打开（你会得到502）：gcloud app browse
3）检查日志：gcloud app logs read

2018-12-11 21:44:56 default[20181211t134352]  "GET / HTTP/1.1" 502
2018-12-11 21:44:57 default[20181211t134352]  2018/12/11 21:44:57 [DEBUG] metadata scopes: https://www.googleapis.com/auth/appengine.apis
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/cloud-platform
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/cloud_debugger
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/devstorage.full_control
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/logging.write
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/monitoring.write
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/trace.append
2018-12-11 21:44:57 default[20181211t134352]  https://www.googleapis.com/auth/userinfo.email
2018-12-11 21:44:57 default[20181211t134352]  .
2018-12-11 21:44:57 default[20181211t134352]  2018/12/11 21:44:57 Listening on port 8081
2018-12-11 21:44:58 default[20181211t134352]  2018/12/11 21:44:58 Unable to retrieve data from sheet: googleapi: Error 403: Request had insufficient authentication scopes., forbidden

有人可以帮助了解如何修复它吗？

示例项目：https://github.com/vistrcm/gae-spreadsheet-issue https://github.com/vistrcm/gae-spreadsheet-issue

我之前在 App Engine 到 G Suite 的集成中也遇到过这个问题。您需要使用服务帐户密钥。默认的还不够（我相信是因为它没有私钥，但这可能是错误的）。

本质上，您需要使用代码上传密钥并使用它来获取Client（而不是使用默认的）：

func getOauthClient(serviceAccountKeyPath string) *http.Client {
    ctx := context.Background()
    data, err := ioutil.ReadFile(serviceAccountKeyPath)
    if err != nil {
        log.Fatal(err)
    }
    creds, err := google.CredentialsFromJSON(ctx, data, "https://www.googleapis.com/auth/spreadsheets.readonly")
    if err != nil {
        log.Fatal(err)
    }

    return oauth2.NewClient(ctx, creds.TokenSource)
}