如何使用 golang 在另一个 Lambda 函数中调用一个 Lambda 函数

Question

我正在尝试在另一个 lambda 函数中调用一个 lambda 函数。我有 lambda 函数的调用动作，但是，我似乎无法让使用的 lambda 函数从发送 lambda 函数接收有效负载/正文。

Lambda go doc 关于调用 lambda 函数

这是我发送/调用 lambda 函数

type Response events.APIGatewayProxyResponse

func Handler(ctx context.Context) (Response, error) {

    region := os.Getenv("AWS_REGION")

    session, err := session.NewSession(&aws.Config{ // Use aws sdk to connect to dynamoDB

        Region: &region,

    })

    svc := invoke.New(session)

    payload, err := json.Marshal(map[string]interface{}{

        "message": "message to other lambda func",

    })

    if err != nil {

        fmt.Println("Json Marshalling error")

    }

    input := &invoke.InvokeInput{

        FunctionName:   aws.String("invokeConsume"),

        InvocationType: aws.String("RequestResponse"),

        LogType:        aws.String("Tail"),

        Payload:        payload,

    }

    result, err := svc.Invoke(input)

    if err != nil {

        fmt.Println("error")

        fmt.Println(err.Error())

    }

    var m map[string]interface{}

    json.Unmarshal(result.Payload, &m)

    fmt.Println(m["body"])

    body, err := json.Marshal(m["body"])

    resp := Response{

        StatusCode:      200,

        IsBase64Encoded: false,

        Headers: map[string]string{

            "Content-Type": "application/json",

        },

        Body: string(body),

    }

    fmt.Println(resp)

    return resp, nil

}

func main() {

    lambda.Start(Handler)

}

我从调用的 lambda 中得到的响应......

{200 map[Content-Type:application/json] "{\"message\":\"Something\"}" false} 

Answer 1

我不得不将 body 对象也包含到有效负载中。这是使用 golang 在另一个 lambda 函数中调用 lambda 函数的完整解决方案region := os.Getenv("AWS_REGION")session, err := session.NewSession(&aws.Config{ // Use aws sdk to connect to dynamoDB    Region: &region,})svc := invoke.New(session)body, err := json.Marshal(map[string]interface{}{    "name": "Jimmy",})type Payload struct {    // You can also include more objects in the structure like below,     // but for my purposes body was all that was required    // Method string `json:"httpMethod"`    Body string `json:"body"`}p := Payload{    // Method: "POST",    Body: string(body),}payload, err := json.Marshal(p)  // Result should be: {"body":"{\"name\":\"Jimmy\"}"}  // This is the required format for the lambda request body.if err != nil {    fmt.Println("Json Marshalling error")}fmt.Println(string(payload))input := &invoke.InvokeInput{    FunctionName:   aws.String("invokeConsume"),    InvocationType: aws.String("RequestResponse"),    LogType:        aws.String("Tail"),    Payload:        payload,}result, err := svc.Invoke(input)if err != nil {    fmt.Println("error")    fmt.Println(err.Error())}var m map[string]interface{}json.Unmarshal(result.Payload, &m)fmt.Println(m["body"])invokeReponse, err := json.Marshal(m["body"])resp := Response{    StatusCode:      200,    IsBase64Encoded: false,    Headers: map[string]string{        "Content-Type": "application/json",    },    Body: string(invokeReponse),}fmt.Println(resp)return resp, nil

Answer 2

我认为您需要确保选择Use lambda proxy integration此选项可以让您接收有效负载数据。

Answer 3

问题似乎是您没有将正确的 API 网关代理请求事件传递给您的消费者 lambda：如果您查看Amazon 的示例事件页面，您会发现 API 网关事件具有以下结构（或多或少）{  "path": "/test/hello",  "headers": {    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",    "Accept-Encoding": "gzip, deflate, lzma, sdch, br",    "Accept-Language": "en-US,en;q=0.8",    "CloudFront-Forwarded-Proto": "https",    "CloudFront-Is-Desktop-Viewer": "true",    "CloudFront-Is-Mobile-Viewer": "false",    "CloudFront-Is-SmartTV-Viewer": "false",    "CloudFront-Is-Tablet-Viewer": "false",    "CloudFront-Viewer-Country": "US",    "Host": "wt6mne2s9k.execute-api.us-west-2.amazonaws.com",    "Upgrade-Insecure-Requests": "1",    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",    "Via": "1.1 fb7cca60f0ecd82ce07790c9c5eef16c.cloudfront.net (CloudFront)",    "X-Amz-Cf-Id": "nBsWBOrSHMgnaROZJK1wGCZ9PcRcSpq_oSXZNQwQ10OTZL4cimZo3g==",    "X-Forwarded-For": "192.168.100.1, 192.168.1.1",    "X-Forwarded-Port": "443",    "X-Forwarded-Proto": "https"  },  "pathParameters": {    "proxy": "hello"  },  "requestContext": {    "accountId": "123456789012",    "resourceId": "us4z18",    "stage": "test",    "requestId": "41b45ea3-70b5-11e6-b7bd-69b5aaebc7d9",    "identity": {      "cognitoIdentityPoolId": "",      "accountId": "",      "cognitoIdentityId": "",      "caller": "",      "apiKey": "",      "sourceIp": "192.168.100.1",      "cognitoAuthenticationType": "",      "cognitoAuthenticationProvider": "",      "userArn": "",      "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",      "user": ""    },    "resourcePath": "/{proxy+}",    "httpMethod": "GET",    "apiId": "wt6mne2s9k"  },  "resource": "/{proxy+}",  "httpMethod": "GET",  "queryStringParameters": {    "name": "me"  },  "stageVariables": {    "stageVarName": "stageVarValue"  }}如您所见，大多数字段都与 HTTP 内容相关，这是因为 API 网关旨在作为一种将您的 lambda 函数公开到网络的方式（也称为制作 REST API）。您可以更改 lambda 以接受新的事件类型（它必须是 JSON 可序列化类型）或用作字符串并自行序列化。

Answer 4

AWS SDK 有一个例子： https://github.com/awsdocs/aws-doc-sdk-examples/blob/master/go/example_code/lambda/aws-go-sdk-lambda-example-run-function.gopackage mainimport (    "github.com/aws/aws-sdk-go/aws"    "github.com/aws/aws-sdk-go/aws/session"    "github.com/aws/aws-sdk-go/service/lambda"        "encoding/json"    "fmt"    "os"    "strconv")type getItemsRequest struct {    SortBy     string    SortOrder  string    ItemsToGet int}type getItemsResponseError struct {    Message string `json:"message"`}type getItemsResponseData struct {    Item string `json:"item"`}type getItemsResponseBody struct {    Result string                 `json:"result"`    Data   []getItemsResponseData `json:"data"`    Error  getItemsResponseError  `json:"error"`}type getItemsResponseHeaders struct {    ContentType string `json:"Content-Type"`}type getItemsResponse struct {    StatusCode int                     `json:"statusCode"`    Headers    getItemsResponseHeaders `json:"headers"`    Body       getItemsResponseBody    `json:"body"`}func main() {    // Create Lambda service client    sess := session.Must(session.NewSessionWithOptions(session.Options{        SharedConfigState: session.SharedConfigEnable,    }))    client := lambda.New(sess, &aws.Config{Region: aws.String("us-west-2")})    // Get the 10 most recent items    request := getItemsRequest{"time", "descending", 10}    payload, err := json.Marshal(request)    if err != nil {        fmt.Println("Error marshalling MyGetItemsFunction request")        os.Exit(0)    }    result, err := client.Invoke(&lambda.InvokeInput{FunctionName: aws.String("MyGetItemsFunction"), Payload: payload})    if err != nil {        fmt.Println("Error calling MyGetItemsFunction")        os.Exit(0)    }    var resp getItemsResponse    err = json.Unmarshal(result.Payload, &resp)    if err != nil {        fmt.Println("Error unmarshalling MyGetItemsFunction response")        os.Exit(0)    }    // If the status code is NOT 200, the call failed    if resp.StatusCode != 200 {        fmt.Println("Error getting items, StatusCode: " + strconv.Itoa(resp.StatusCode))        os.Exit(0)    }    // If the result is failure, we got an error    if resp.Body.Result == "failure" {        fmt.Println("Failed to get items")        os.Exit(0)    }    // Print out items    if len(resp.Body.Data) > 0 {        for i := range resp.Body.Data {            fmt.Println(resp.Body.Data[i].Item)        }    } else {        fmt.Println("There were no items")    }}