Panic Laufzeitfehler beim Abrufen von Datensätzen aus DynamoDB mit Golang

Question

Ich habe Probleme beim Zugriff auf aws-sdk-go, ich versuche, mit Dynamo DB Verbindung mit AWS-SDK-Go. Ich bin in der Lage, Verbindung zur Datenbank herstellen und einfügen Operation funktioniert gut, aber wenn ich versuche, Daten aus der Tabelle abrufen, bekomme ich "Panik-Laufzeitfehler ungültige Speicheradresse oder Nullzeiger Dereferenz Golang" Fehler. Bitte finden Sie den Code, den ich verwendet habe. Ich bin neu in beiden Technologien.

package main 
import (
    "github.com/aws/aws-sdk-go/aws" 
    "github.com/aws/aws-sdk-go/aws/session" 
    "github.com/aws/aws-sdk-go/aws/credentials" 
    "github.com/aws/aws-sdk-go/service/dynamodb" 
    "github.com/user/dynamo_connect/data" 
    "github.com/user/insert_api/read" 
) 
import (
    "fmt" 
    "log" 
    "net/http" 
    "crypto/md5" 
    "encoding/hex" 
    "io" 
    "time" 
    "github.com/gorilla/mux" 
) 

func main() { 
    router := mux.NewRouter().StrictSlash(true) 
    router.HandleFunc("/get", GetCampaignRecord) 
    log.Fatal(http.ListenAndServe(":8080", router)) 
} 

func GetCampaignRecord(w http.ResponseWriter, r *http.Request) { 
    var testCredentials = credentials.NewStaticCredentials("AKIxxxxxxxxxxxxxxxxx", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", "") 
    sess, err := session.NewSession() 
    svc := dynamodb.New(sess, &aws.Config{ 
    Region: aws.String("ap-south-1"), 
    Credentials: testCredentials, 
    }) 

    resp, err := read.GetCampaignData(svc) 
    if err != nil { 
    fmt.Println("An error occurred while writing to the Employee table") 
    fmt.Println(err.Error()) 
    } 

    if resp != nil { 
    fmt.Println("An error occurred while writing to the Employee table") 
    fmt.Println(err.Error()) 
    } 
} 

Paket lesen

package read 
    import "github.com/aws/aws-sdk-go/service/dynamodb" 
    import "github.com/aws/aws-sdk-go/aws" 

    func GetCampaignData(svc *dynamodb.DynamoDB) (*dynamodb.BatchGetItemOutput, error) { 
     params := &dynamodb.BatchGetItemInput{ 
     RequestItems: map[string]*dynamodb.KeysAndAttributes{ 
      "employee": { 
       Keys: []map[string]*dynamodb.AttributeValue{ 
        { 
         "employee_id": { 
          S: aws.String("1"), 
         }, 
        }, 
       }, 
       ProjectionExpression: aws.String("employee_id, employee_name"), 
      }, 
     }, 
     ReturnConsumedCapacity: aws.String("TOTAL"), 
    } 

    return svc.BatchGetItem(params) 
    } 

Full Error Ich erhalte

http: panic serving 127.0.0.1:36034: runtime error: invalid memory address or nil pointer dereference goroutine 18 [running]: net/http.(*conn).serve.func1(0xc820102000) /usr/local/go/src/net/http/server.go:1389 +0xc1 panic(0x8919a0, 0xc82000a110) /usr/local/go/src/runtime/panic.go:443 +0x4e9 github.com/aws/aws-sdk-go/aws/session.(*Session).Copy(0x0, 0xc82012a020, 0x1, 0x1, 0x0) /home/MyUser/work/src/github.com/aws/aws-sdk-go/aws/session/session.go:365 +0x2a github.com/aws/aws-sdk-go/aws/session.(*Session).ClientConfig(0x0, 0x935410, 0x8, 0xc82012a020, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0, ...) /home/MyUser/work/src/github.com/aws/aws-sdk-go/aws/session/session.go:378 +0x72 github.com/aws/aws-sdk-go/service/dynamodb.New(0x7f20477cd248, 0x0, 0xc82012a020, 0x1, 0x1, 0xc820112260) /home/MyUser/work/src/github.com/aws/aws-sdk-go/service/dynamodb/service.go:153 +0x78 main.GetCampaignRecord(0x7f20477cd058, 0xc820122000, 0xc82010e000) /home/MyUser/work/src/github.com/user/insert_api/insert_api.go:80 +0x329 net/http.HandlerFunc.ServeHTTP(0xa07d38, 0x7f20477cd058, 0xc820122000, 0xc82010e000) /usr/local/go/src/net/http/server.go:1618 +0x3a github.com/gorilla/mux.(*Router).ServeHTTP(0xc8200125a0, 0x7f20477cd058, 0xc820122000, 0xc82010e000) /home/MyUser/work/src/github.com/gorilla/mux/mux.go:114 +0x2a8 net/http.serverHandler.ServeHTTP(0xc82006e180, 0x7f20477cd058, 0xc820122000, 0xc82010e000) /usr/local/go/src/net/http/server.go:2081 +0x19e net/http.(*conn).serve(0xc820102000) /usr/local/go/src/net/http/server.go:1472 +0xf2e created by net/http.(*Server).Serve /usr/local/go/src/net/http/server.go:2137 +0x44e 2016/11/19 13:31:34 http: panic serving 127.0.0.1:36035: runtime error: invalid memory address or nil pointer dereference goroutine 5 [running]: net/http.(*conn).serve.func1(0xc82006e200) /usr/local/go/src/net/http/server.go:1389 +0xc1 panic(0x8919a0, 0xc82000a110) /usr/local/go/src/runtime/panic.go:443 +0x4e9 github.com/aws/aws-sdk-go/aws/session.(*Session).Copy(0x0, 0xc82012a038, 0x1, 0x1, 0x0) /home/MyUser/work/src/github.com/aws/aws-sdk-go/aws/session/session.go:365 +0x2a github.com/aws/aws-sdk-go/aws/session.(*Session).ClientConfig(0x0, 0x935410, 0x8, 0xc82012a038, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0, ...) /home/MyUser/work/src/github.com/aws/aws-sdk-go/aws/session/session.go:378 +0x72 github.com/aws/aws-sdk-go/service/dynamodb.New(0x7f20477cd248, 0x0, 0xc82012a038, 0x1, 0x1, 0xc820112540) /home/MyUser/work/src/github.com/aws/aws-sdk-go/service/dynamodb/service.go:153 +0x78 main.GetCampaignRecord(0x7f20477cd058, 0xc8201224e0, 0xc8200d20e0) /home/MyUser/work/src/github.com/user/insert_api/insert_api.go:80 +0x329 net/http.HandlerFunc.ServeHTTP(0xa07d38, 0x7f20477cd058, 0xc8201224e0, 0xc8200d20e0) /usr/local/go/src/net/http/server.go:1618 +0x3a github.com/gorilla/mux.(*Router).ServeHTTP(0xc8200125a0, 0x7f20477cd058, 0xc8201224e0, 0xc8200d20e0) /home/MyUser/work/src/github.com/gorilla/mux/mux.go:114 +0x2a8 net/http.serverHandler.ServeHTTP(0xc82006e180, 0x7f20477cd058, 0xc8201224e0, 0xc8200d20e0) /usr/local/go/src/net/http/server.go:2081 +0x19e net/http.(*conn).serve(0xc82006e200) /usr/local/go/src/net/http/server.go:1472 +0xf2e created by net/http.(*Server).Serve /usr/local/go/src/net/http/server.go:2137 +0x44e 2016/11/19 13:31:34 http: panic serving 127.0.0.1:36036: runtime error: invalid memory address or nil pointer dereference goroutine 34 [running]: net/http.(*conn).serve.func1(0xc820114280) /usr/local/go/src/net/http/server.go:1389 +0xc1 panic(0x8919a0, 0xc82000a110) /usr/local/go/src/runtime/panic.go:443 +0x4e9 github.com/aws/aws-sdk-go/aws/session.(*Session).Copy(0x0, 0xc82012a058, 0x1, 0x1, 0x0) /home/MyUser/work/src/github.com/aws/aws-sdk-go/aws/session/session.go:365 +0x2a github.com/aws/aws-sdk-go/aws/session.(*Session).ClientConfig(0x0, 0x935410, 0x8, 0xc82012a058, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0, ...) /home/MyUser/work/src/github.com/aws/aws-sdk-go/aws/session/session.go:378 +0x72 github.com/aws/aws-sdk-go/service/dynamodb.New(0x7f20477cd248, 0x0, 0xc82012a058, 0x1, 0x1, 0xc820112840) /home/MyUser/work/src/github.com/aws/aws-sdk-go/service/dynamodb/service.go:153 +0x78 main.GetCampaignRecord(0x7f20477cd058, 0xc820122820, 0xc82016c000) /home/MyUser/work/src/github.com/user/insert_api/insert_api.go:80 +0x329 net/http.HandlerFunc.ServeHTTP(0xa07d38, 0x7f20477cd058, 0xc820122820, 0xc82016c000) /usr/local/go/src/net/http/server.go:1618 +0x3a github.com/gorilla/mux.(*Router).ServeHTTP(0xc8200125a0, 0x7f20477cd058, 0xc820122820, 0xc82016c000) /home/MyUser/work/src/github.com/gorilla/mux/mux.go:114 +0x2a8 net/http.serverHandler.ServeHTTP(0xc82006e180, 0x7f20477cd058, 0xc820122820, 0xc82016c000) /usr/local/go/src/net/http/server.go:2081 +0x19e net/http.(*conn).serve(0xc820114280) /usr/local/go/src/net/http/server.go:1472 +0xf2e created by net/http.(*Server).Serve /usr/local/go/src/net/http/server.go:2137 +0x44e

Answer 1

Ich habe durch den Code gegangen und es scheint mir, dass es ein Problem mit Ihrer Datenbank-Konnektivität ist. Sie versuchen, eine Verbindung zu einer anderen Region herzustellen. Also, bitte überprüfen Sie zuerst Ihre Region. Es ist dort in der URL von AWS-Konto Ihrer dynamodb. (Z. B. us-Ost-2). Sie können Ihre Region auch überprüfen oder konfigurieren, indem Sie diesen Befehl in das Terminal eingeben: aws configure. Dann werden Sie aufgefordert, Ihren Zugangsschlüssel, geheimen Schlüssel, Regionsnamen usw. einzugeben. Geben Sie hier alle Details ein. Das ist es. Prost.