XrayForLambda.go

xrayforlambda.go

package tracing

import (
	"context"
	"encoding/json"
	"fmt"
	"os"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/dynamodb"
	"github.com/aws/aws-xray-sdk-go/xray"
	"github.com/aws/aws-xray-sdk-go/xraylog"
)

func Handler(ctx context.Context, req events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
	lgr := xraylog.NewDefaultLogger(os.Stdout, xraylog.LogLevelDebug)
	xray.SetLogger(lgr)

	traceID := ""
	headers := req.Headers
	if headers != nil {
		traceID = headers["X-Amzn-Trace-Id"]
	}

	fmt.Printf("context %v", ctx)
	b, _ := json.Marshal(req)
	fmt.Printf("req %s", b)

	dynamo := dynamodb.New(session.Must(session.NewSession()))
	xray.AWS(dynamo.Client)
	if _, err := dynamo.ListTablesWithContext(ctx, &dynamodb.ListTablesInput{}); err != nil {
		fmt.Printf("dynamo error: %s", err)
		return events.APIGatewayProxyResponse{
			Body:       "",
			StatusCode: 400,
		}, fmt.Errorf("failed listing tables")
	}

	return events.APIGatewayProxyResponse{
		Body:       fmt.Sprintf("trace: %s", traceID),
		StatusCode: 200,
	}, nil
}

/* this needs to live in some main package
func main() {
	lambda.Start(Handler)
}
*/