无法以编程方式调用AWS Lambda

Question

I am importing the lambda service as follows:

import (
    lambdaservice "github.com/aws/aws-sdk-go/service/lambda"
)

and use it as follows:

func InvokeCreateSessionLambda(payload invoketypes.Input) {
    l := &lambdaservice.Lambda{}
    data, _ := json.Marshal(payload)

    input := &lambdaservice.InvokeInput{
        Payload:        data,
        InvocationType: aws.String("RequestResponse"),
        FunctionName:   aws.String("MyValidFunctionARN"),
        ClientContext:  aws.String("{\"service\":\"somedata\"}"),
    }
    err := input.Validate()
    fmt.Println(err) // prints  <nil>
    r, e := l.Invoke(input) <panic>
    fmt.Print(e)
    fmt.Print(r)
}

but l.Invoke(input) panics with the (relevant) stack trace:

runtime error: invalid memory address or nil pointer dereference
<skipped some lines>
panic(0xac91e0, 0x1214ef0)
    /usr/local/go/src/runtime/panic.go:522 +0x1b5
test-lambda-go/vendor/github.com/aws/aws-sdk-go/aws/client.(*Client).NewRequest(...)
    /home/ayush/projects/gojects/src/test-lambda-go/vendor/github.com/aws/aws-sdk-go/aws/client/client.go:84
test-lambda-go/vendor/github.com/aws/aws-sdk-go/service/lambda.(*Lambda).newRequest(0xc000107498, 0xc0001f0680, 0xb22ac0, 0xc0001f0640, 0xb12080, 0xc0001f06c0, 0xc0000e2480)
    /home/ayush/projects/gojects/src/test-lambda-go/vendor/github.com/aws/aws-sdk-go/service/lambda/service.go:87 +0x3e
test-lambda-go/vendor/github.com/aws/aws-sdk-go/service/lambda.(*Lambda).InvokeRequest(0xc000107498, 0xc0001f0640, 0x6, 0xc0001fa000)
    /home/ayush/projects/gojects/src/test-lambda-go/vendor/github.com/aws/aws-sdk-go/service/lambda/api.go:1895 +0x102
test-lambda-go/vendor/github.com/aws/aws-sdk-go/service/lambda.(*Lambda).Invoke(0xc000107498, 0xc0001f0640, 0xc0001074c0, 0x1, 0x1)
    /home/ayush/projects/gojects/src/test-lambda-go/vendor/github.com/aws/aws-sdk-go/service/lambda/api.go:2017 +0x35

Any idea what's causing the error and how to fix this?

Answer 1

Try using the New function in the lambda package.

sess := session.Must(session.NewSessionWithOptions(session.Options{
    SharedConfigState: session.SharedConfigEnable,
}))

client := lambda.New(sess, &aws.Config{Region: aws.String("us-west-2")})