Golang awserr.New函數代碼示例

// loadProfiles loads from the file pointed to by shared credentials filename for profile.
// The credentials retrieved from the profile will be returned or error. Error will be
// returned if it fails to read from the file, or the data is invalid.
func loadProfile(filename, profile string) (Value, error) {
	config, err := ini.LoadFile(filename)
	if err != nil {
		return Value{}, awserr.New("SharedCredsLoad", "failed to load shared credentials file", err)
	}
	iniProfile := config.Section(profile)

	id, ok := iniProfile["aws_access_key_id"]
	if !ok {
		return Value{}, awserr.New("SharedCredsAccessKey",
			fmt.Sprintf("shared credentials %s in %s did not contain aws_access_key_id", profile, filename),
			nil)
	}

	secret, ok := iniProfile["aws_secret_access_key"]
	if !ok {
		return Value{}, awserr.New("SharedCredsSecret",
			fmt.Sprintf("shared credentials %s in %s did not contain aws_secret_access_key", profile, filename),
			nil)
	}

	token := iniProfile["aws_session_token"]

	return Value{
		AccessKeyID:     id,
		SecretAccessKey: secret,
		SessionToken:    token,
	}, nil
}

// UnmarshalError unmarshals an error response for a JSON RPC service.
func UnmarshalError(req *request.Request) {
	defer req.HTTPResponse.Body.Close()
	bodyBytes, err := ioutil.ReadAll(req.HTTPResponse.Body)
	if err != nil {
		req.Error = awserr.New("SerializationError", "failed reading JSON RPC error response", err)
		return
	}
	if len(bodyBytes) == 0 {
		req.Error = awserr.NewRequestFailure(
			awserr.New("SerializationError", req.HTTPResponse.Status, nil),
			req.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		req.Error = awserr.New("SerializationError", "failed decoding JSON RPC error response", err)
		return
	}

	codes := strings.SplitN(jsonErr.Code, "#", 2)
	req.Error = awserr.NewRequestFailure(
		awserr.New(codes[len(codes)-1], jsonErr.Message, nil),
		req.HTTPResponse.StatusCode,
		req.RequestID,
	)
}

// UnmarshalError unmarshals an error response for an AWS Query service.
func UnmarshalError(r *request.Request) {
	defer r.HTTPResponse.Body.Close()

	resp := &xmlErrorResponse{}
	err := xml.NewDecoder(r.HTTPResponse.Body).Decode(resp)
	if err != nil && err != io.EOF {
		r.Error = awserr.New("SerializationError", "failed to decode query XML error response", err)
	} else {
		r.Error = awserr.NewRequestFailure(
			awserr.New(resp.Code, resp.Message, nil),
			r.HTTPResponse.StatusCode,
			resp.RequestID,
		)
	}
}

// Retrieve retrieves credentials from the EC2 service.
// Error will be returned if the request fails, or unable to extract
// the desired credentials.
func (m *EC2RoleProvider) Retrieve() (credentials.Value, error) {
	if m.Client == nil {
		m.Client = ec2metadata.New(nil)
	}

	credsList, err := requestCredList(m.Client)
	if err != nil {
		return credentials.Value{}, err
	}

	if len(credsList) == 0 {
		return credentials.Value{}, awserr.New("EmptyEC2RoleList", "empty EC2 Role list", nil)
	}
	credsName := credsList[0]

	roleCreds, err := requestCred(m.Client, credsName)
	if err != nil {
		return credentials.Value{}, err
	}

	m.SetExpiration(roleCreds.Expiration, m.ExpiryWindow)

	return credentials.Value{
		AccessKeyID:     roleCreds.AccessKeyID,
		SecretAccessKey: roleCreds.SecretAccessKey,
		SessionToken:    roleCreds.Token,
	}, nil
}

// Build builds a JSON payload for a JSON RPC request.
func Build(req *request.Request) {
	var buf []byte
	var err error
	if req.ParamsFilled() {
		buf, err = jsonutil.BuildJSON(req.Params)
		if err != nil {
			req.Error = awserr.New("SerializationError", "failed encoding JSON RPC request", err)
			return
		}
	} else {
		buf = emptyJSON
	}

	if req.Service.TargetPrefix != "" || string(buf) != "{}" {
		req.SetBufferBody(buf)
	}

	if req.Service.TargetPrefix != "" {
		target := req.Service.TargetPrefix + "." + req.Operation.Name
		req.HTTPRequest.Header.Add("X-Amz-Target", target)
	}
	if req.Service.JSONVersion != "" {
		jsonVersion := req.Service.JSONVersion
		req.HTTPRequest.Header.Add("Content-Type", "application/x-amz-json-"+jsonVersion)
	}
}

// requestCredList requests a list of credentials from the EC2 service.
// If there are no credentials, or there is an error making or receiving the request
func requestCredList(client *ec2metadata.Client) ([]string, error) {
	resp, err := client.GetMetadata(iamSecurityCredsPath)
	if err != nil {
		return nil, awserr.New("EC2RoleRequestError", "failed to list EC2 Roles", err)
	}

	credsList := []string{}
	s := bufio.NewScanner(strings.NewReader(resp))
	for s.Scan() {
		credsList = append(credsList, s.Text())
	}

	if err := s.Err(); err != nil {
		return nil, awserr.New("SerializationError", "failed to read list of EC2 Roles", err)
	}

	return credsList, nil
}

func unmarshalError(r *request.Request) {
	defer r.HTTPResponse.Body.Close()
	_, err := ioutil.ReadAll(r.HTTPResponse.Body)
	if err != nil {
		r.Error = awserr.New("SerializationError", "unable to unmarshal EC2 metadata error respose", err)
	}

	// TODO extract the error...
}

func unmarshalHandler(r *request.Request) {
	defer r.HTTPResponse.Body.Close()
	b, err := ioutil.ReadAll(r.HTTPResponse.Body)
	if err != nil {
		r.Error = awserr.New("SerializationError", "unable to unmarshal EC2 metadata respose", err)
	}

	data := r.Data.(*metadataOutput)
	data.Content = string(b)
}

// Unmarshal unmarshals a response for a JSON RPC service.
func Unmarshal(req *request.Request) {
	defer req.HTTPResponse.Body.Close()
	if req.DataFilled() {
		err := jsonutil.UnmarshalJSON(req.Data, req.HTTPResponse.Body)
		if err != nil {
			req.Error = awserr.New("SerializationError", "failed decoding JSON RPC response", err)
		}
	}
	return
}

// internal logic for deciding whether to upload a single part or use a
// multipart upload.
func (u *uploader) upload() (*UploadOutput, error) {
	u.init()

	if u.opts.PartSize < MinUploadPartSize {
		msg := fmt.Sprintf("part size must be at least %d bytes", MinUploadPartSize)
		return nil, awserr.New("ConfigError", msg, nil)
	}

	// Do one read to determine if we have more than one part
	buf, err := u.nextReader()
	if err == io.EOF || err == io.ErrUnexpectedEOF { // single part
		return u.singlePart(buf)
	} else if err != nil {
		return nil, awserr.New("ReadRequestBody", "read upload data failed", err)
	}

	mu := multiuploader{uploader: u}
	return mu.upload(buf)
}

// Unmarshal unmarshals a response for an AWS Query service.
func Unmarshal(r *request.Request) {
	defer r.HTTPResponse.Body.Close()
	if r.DataFilled() {
		decoder := xml.NewDecoder(r.HTTPResponse.Body)
		err := xmlutil.UnmarshalXML(r.Data, decoder, r.Operation.Name+"Result")
		if err != nil {
			r.Error = awserr.New("SerializationError", "failed decoding Query response", err)
			return
		}
	}
}

func unmarshalBody(r *request.Request, v reflect.Value) {
	if field, ok := v.Type().FieldByName("SDKShapeTraits"); ok {
		if payloadName := field.Tag.Get("payload"); payloadName != "" {
			pfield, _ := v.Type().FieldByName(payloadName)
			if ptag := pfield.Tag.Get("type"); ptag != "" && ptag != "structure" {
				payload := v.FieldByName(payloadName)
				if payload.IsValid() {
					switch payload.Interface().(type) {
					case []byte:
						b, err := ioutil.ReadAll(r.HTTPResponse.Body)
						if err != nil {
							r.Error = awserr.New("SerializationError", "failed to decode REST response", err)
						} else {
							payload.Set(reflect.ValueOf(b))
						}
					case *string:
						b, err := ioutil.ReadAll(r.HTTPResponse.Body)
						if err != nil {
							r.Error = awserr.New("SerializationError", "failed to decode REST response", err)
						} else {
							str := string(b)
							payload.Set(reflect.ValueOf(&str))
						}
					default:
						switch payload.Type().String() {
						case "io.ReadSeeker":
							payload.Set(reflect.ValueOf(aws.ReadSeekCloser(r.HTTPResponse.Body)))
						case "aws.ReadSeekCloser", "io.ReadCloser":
							payload.Set(reflect.ValueOf(r.HTTPResponse.Body))
						default:
							r.Error = awserr.New("SerializationError",
								"failed to decode REST response",
								fmt.Errorf("unknown payload type %s", payload.Type()))
						}
					}
				}
			}
		}
	}
}

// Unmarshal unmarshals a payload response for the REST XML protocol.
func Unmarshal(r *request.Request) {
	if t := rest.PayloadType(r.Data); t == "structure" || t == "" {
		defer r.HTTPResponse.Body.Close()
		decoder := xml.NewDecoder(r.HTTPResponse.Body)
		err := xmlutil.UnmarshalXML(r.Data, decoder, "")
		if err != nil {
			r.Error = awserr.New("SerializationError", "failed to decode REST XML response", err)
			return
		}
	} else {
		rest.Unmarshal(r)
	}
}

// Build builds a request payload for the REST XML protocol.
func Build(r *request.Request) {
	rest.Build(r)

	if t := rest.PayloadType(r.Params); t == "structure" || t == "" {
		var buf bytes.Buffer
		err := xmlutil.BuildXML(r.Params, xml.NewEncoder(&buf))
		if err != nil {
			r.Error = awserr.New("SerializationError", "failed to encode rest XML request", err)
			return
		}
		r.SetBufferBody(buf.Bytes())
	}
}

// contentMD5 computes and sets the HTTP Content-MD5 header for requests that
// require it.
func contentMD5(r *request.Request) {
	h := md5.New()

	// hash the body.  seek back to the first position after reading to reset
	// the body for transmission.  copy errors may be assumed to be from the
	// body.
	_, err := io.Copy(h, r.Body)
	if err != nil {
		r.Error = awserr.New("ContentMD5", "failed to read body", err)
		return
	}
	_, err = r.Body.Seek(0, 0)
	if err != nil {
		r.Error = awserr.New("ContentMD5", "failed to seek body", err)
		return
	}

	// encode the md5 checksum in base64 and set the request header.
	sum := h.Sum(nil)
	sum64 := make([]byte, base64.StdEncoding.EncodedLen(len(sum)))
	base64.StdEncoding.Encode(sum64, sum)
	r.HTTPRequest.Header.Set("Content-MD5", string(sum64))
}