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// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT-0
// snippet-start:[lambda.go.run_function]
package main
// snippet-start:[lambda.go.run_function.imports]
import (
"encoding/json"
"flag"
"fmt"
"strconv"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/lambda"
"github.com/aws/aws-sdk-go/service/lambda/lambdaiface"
)
// snippet-end:[lambda.go.run_function.imports]
// snippet-start:[lambda.go.run_function.structs]
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" `
}
// snippet-end:[lambda.go.run_function.structs]
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// CallFunction calls an AWS Lambda function
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// Inputs:
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// svc is an AWS Lambda service client
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// maxItems is the maximum number of items to retrieve
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// function is the name of the AWS Lambda function
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// Output:
// If success, the results of the function call and nil
// Otherwise, nil and an error from the call to Invoke
func CallFunction ( svc lambdaiface . LambdaAPI , maxItems * int , function * string ) ( * lambda . InvokeOutput , error ) {
// snippet-start:[lambda.go.run_function.marshall]
request := getItemsRequest { "time" , "descending" , * maxItems }
payload , err := json . Marshal ( request )
// snippet-end:[lambda.go.run_function.marshall]
if err != nil {
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fmt . Println ( "Got an error marshalling the request" )
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return nil , err
}
// snippet-start:[lambda.go.run_function.call]
result , err := svc . Invoke ( & lambda . InvokeInput {
FunctionName : function ,
Payload : payload ,
} )
// snippet-end:[lambda.go.run_function.call]
return result , err
}
func main ( ) {
// snippet-start:[lambda.go.run_function.args]
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function := flag . String ( "f" , "" , "The name of the AWS Lambda function to invoke" )
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maxItems := flag . Int ( "m" , 10 , "The maximum number of items to retrieve" )
flag . Parse ( )
if * function == "" || * maxItems < 0 {
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fmt . Println ( "You must supply a function to call and maximum number of items to retrieve that is greater than zero" )
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return
}
// snippet-end:[lambda.go.run_function.args]
// snippet-start:[lambda.go.run_function.session]
sess := session . Must ( session . NewSessionWithOptions ( session . Options {
SharedConfigState : session . SharedConfigEnable ,
} ) )
svc := lambda . New ( sess )
// snippet-end:[lambda.go.run_function.session]
result , err := CallFunction ( svc , maxItems , function )
if err != nil {
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fmt . Println ( "Got error calling " + * function + ":" )
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fmt . Println ( err )
return
}
// snippet-start:[lambda.go.run_function.unmarshall]
var resp getItemsResponse
err = json . Unmarshal ( result . Payload , & resp )
// snippet-end:[lambda.go.run_function.unmarshall]
if err != nil {
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fmt . Println ( "Got an error unmarshalling the response" )
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fmt . Println ( err )
return
}
// If the status code is NOT 200, the call failed
if resp . StatusCode != 200 {
fmt . Println ( "Error getting items, StatusCode: " + strconv . Itoa ( resp . StatusCode ) )
return
}
// If the result is failure, we got an error
if resp . Body . Result == "failure" {
fmt . Println ( "Failed to get items" )
return
}
// snippet-start:[lambda.go.run_function.display]
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" )
}
// snippet-end:[lambda.go.run_function.display]
}
// snippet-end:[lambda.go.run_function]
