func initHandlers(s *Session) {
// Add the Validate parameter handler if it is not disabled.
s.Handlers.Validate.Remove(corehandlers.ValidateParametersHandler)
if !aws.BoolValue(s.Config.DisableParamValidation) {
s.Handlers.Validate.PushBackNamed(corehandlers.ValidateParametersHandler)
}
}
// ClientConfig satisfies the client.ConfigProvider interface and is used to
// configure the service client instances. Passing the Session to the service
// client's constructor (New) will use this method to configure the client.
//
// Example:
// sess := session.New()
// s3.New(sess)
func (s *Session) ClientConfig(serviceName string, cfgs ...*aws.Config) client.Config {
s = s.Copy(cfgs...)
endpoint, signingRegion := endpoints.NormalizeEndpoint(
aws.StringValue(s.Config.Endpoint), serviceName,
aws.StringValue(s.Config.Region), aws.BoolValue(s.Config.DisableSSL))
return client.Config{
Config: s.Config,
Handlers: s.Handlers,
Endpoint: endpoint,
SigningRegion: signingRegion,
}
}
func setupChecksumValidation(r *request.Request) {
if aws.BoolValue(r.Config.DisableComputeChecksums) {
return
}
switch r.Operation.Name {
case opSendMessage:
r.Handlers.Unmarshal.PushBack(verifySendMessage)
case opSendMessageBatch:
r.Handlers.Unmarshal.PushBack(verifySendMessageBatch)
case opReceiveMessage:
r.Handlers.Unmarshal.PushBack(verifyReceiveMessage)
}
}
// CredChain returns the default credential chain.
//
// Generally you shouldn't need to use this method directly, but
// is available if you need to reset the credentials of an
// existing service client or session's Config.
func CredChain(cfg *aws.Config, handlers request.Handlers) *credentials.Credentials {
endpoint, signingRegion := endpoints.EndpointForRegion(ec2metadata.ServiceName, *cfg.Region, true)
return credentials.NewCredentials(&credentials.ChainProvider{
VerboseErrors: aws.BoolValue(cfg.CredentialsChainVerboseErrors),
Providers: []credentials.Provider{
&credentials.EnvProvider{},
&credentials.SharedCredentialsProvider{Filename: "", Profile: ""},
&ec2rolecreds.EC2RoleProvider{
Client: ec2metadata.NewClient(*cfg, handlers, endpoint, signingRegion),
ExpiryWindow: 5 * time.Minute,
},
}})
}
// hostStyleBucketName returns true if the request should put the bucket in
// the host. This is false if S3ForcePathStyle is explicitly set or if the
// bucket is not DNS compatible.
func hostStyleBucketName(r *request.Request, bucket string) bool {
if aws.BoolValue(r.Config.S3ForcePathStyle) {
return false
}
// Bucket might be DNS compatible but dots in the hostname will fail
// certificate validation, so do not use host-style.
if r.HTTPRequest.URL.Scheme == "https" && strings.Contains(bucket, ".") {
return false
}
// GetBucketLocation should be able to be called from any region within
// a partition, and return the associated region of the bucket.
if r.Operation.Name == opGetBucketLocation {
return false
}
// Use host-style if the bucket is DNS compatible
return dnsCompatibleBucketName(bucket)
}
// nextPageTokens returns the tokens to use when asking for the next page of
// data.
func (r *Request) nextPageTokens() []interface{} {
if r.Operation.Paginator == nil {
return nil
}
if r.Operation.TruncationToken != "" {
tr, _ := awsutil.ValuesAtPath(r.Data, r.Operation.TruncationToken)
if len(tr) == 0 {
return nil
}
switch v := tr[0].(type) {
case *bool:
if !aws.BoolValue(v) {
return nil
}
case bool:
if v == false {
return nil
}
}
}
tokens := []interface{}{}
tokenAdded := false
for _, outToken := range r.Operation.OutputTokens {
v, _ := awsutil.ValuesAtPath(r.Data, outToken)
if len(v) > 0 {
tokens = append(tokens, v[0])
tokenAdded = true
} else {
tokens = append(tokens, nil)
}
}
if !tokenAdded {
return nil
}
return tokens
}
func validateCRC32(r *request.Request) {
if r.Error != nil {
return // already have an error, no need to verify CRC
}
// Checksum validation is off, skip
if aws.BoolValue(r.Config.DisableComputeChecksums) {
return
}
// Try to get CRC from response
header := r.HTTPResponse.Header.Get("X-Amz-Crc32")
if header == "" {
return // No header, skip
}
expected, err := strconv.ParseUint(header, 10, 32)
if err != nil {
return // Could not determine CRC value, skip
}
buf, err := drainBody(r.HTTPResponse.Body, r.HTTPResponse.ContentLength)
if err != nil { // failed to read the response body, skip
return
}
// Reset body for subsequent reads
r.HTTPResponse.Body = ioutil.NopCloser(bytes.NewReader(buf.Bytes()))
// Compute the CRC checksum
crc := crc32.ChecksumIEEE(buf.Bytes())
if crc != uint32(expected) {
// CRC does not match, set a retryable error
r.Retryable = aws.Bool(true)
r.Error = awserr.New("CRC32CheckFailed", "CRC32 integrity check failed", nil)
}
}
func fillPresignedURL(r *request.Request) {
if !r.ParamsFilled() {
return
}
origParams := r.Params.(*CopySnapshotInput)
// Stop if PresignedURL/DestinationRegion is set
if origParams.PresignedUrl != nil || origParams.DestinationRegion != nil {
return
}
origParams.DestinationRegion = r.Config.Region
newParams := awsutil.CopyOf(r.Params).(*CopySnapshotInput)
// Create a new request based on the existing request. We will use this to
// presign the CopySnapshot request against the source region.
cfg := r.Config.Copy(aws.NewConfig().
WithEndpoint("").
WithRegion(aws.StringValue(origParams.SourceRegion)))
clientInfo := r.ClientInfo
clientInfo.Endpoint, clientInfo.SigningRegion = endpoints.EndpointForRegion(
clientInfo.ServiceName, aws.StringValue(cfg.Region), aws.BoolValue(cfg.DisableSSL))
// Presign a CopySnapshot request with modified params
req := request.New(*cfg, clientInfo, r.Handlers, r.Retryer, r.Operation, newParams, r.Data)
url, err := req.Presign(5 * time.Minute) // 5 minutes should be enough.
if err != nil { // bubble error back up to original request
r.Error = err
return
}
// We have our URL, set it on params
origParams.PresignedUrl = &url
}
// NewClient returns a new EC2Metadata client. Should be used to create
// a client when not using a session. Generally using just New with a session
// is preferred.
//
// If an unmodified HTTP client is provided from the stdlib default, or no client
// the EC2RoleProvider's EC2Metadata HTTP client's timeout will be shortened.
// To disable this set Config.EC2MetadataDisableTimeoutOverride to false. Enabled by default.
func NewClient(cfg aws.Config, handlers request.Handlers, endpoint, signingRegion string, opts ...func(*client.Client)) *EC2Metadata {
if !aws.BoolValue(cfg.EC2MetadataDisableTimeoutOverride) && httpClientZero(cfg.HTTPClient) {
// If the http client is unmodified and this feature is not disabled
// set custom timeouts for EC2Metadata requests.
cfg.HTTPClient = &http.Client{
// use a shorter timeout than default because the metadata
// service is local if it is running, and to fail faster
// if not running on an ec2 instance.
Timeout: 5 * time.Second,
}
}
svc := &EC2Metadata{
Client: client.New(
cfg,
metadata.ClientInfo{
ServiceName: ServiceName,
Endpoint: endpoint,
APIVersion: "latest",
},
handlers,
),
}
svc.Handlers.Unmarshal.PushBack(unmarshalHandler)
svc.Handlers.UnmarshalError.PushBack(unmarshalError)
svc.Handlers.Validate.Clear()
svc.Handlers.Validate.PushBack(validateEndpointHandler)
// Add additional options to the service config
for _, option := range opts {
option(svc.Client)
}
return svc
}
// Send will send the request returning error if errors are encountered.
//
// Send will sign the request prior to sending. All Send Handlers will
// be executed in the order they were set.
func (r *Request) Send() error {
for {
r.Sign()
if r.Error != nil {
return r.Error
}
if aws.BoolValue(r.Retryable) {
if r.Config.LogLevel.Matches(aws.LogDebugWithRequestRetries) {
r.Config.Logger.Log(fmt.Sprintf("DEBUG: Retrying Request %s/%s, attempt %d",
r.ClientInfo.ServiceName, r.Operation.Name, r.RetryCount))
}
// Re-seek the body back to the original point in for a retry so that
// send will send the body's contents again in the upcoming request.
r.Body.Seek(r.BodyStart, 0)
r.HTTPRequest.Body = ioutil.NopCloser(r.Body)
}
r.Retryable = nil
r.Handlers.Send.Run(r)
if r.Error != nil {
err := r.Error
r.Handlers.Retry.Run(r)
r.Handlers.AfterRetry.Run(r)
if r.Error != nil {
debugLogReqError(r, "Send Request", false, r.Error)
return r.Error
}
debugLogReqError(r, "Send Request", true, err)
continue
}
r.Handlers.UnmarshalMeta.Run(r)
r.Handlers.ValidateResponse.Run(r)
if r.Error != nil {
err := r.Error
r.Handlers.UnmarshalError.Run(r)
r.Handlers.Retry.Run(r)
r.Handlers.AfterRetry.Run(r)
if r.Error != nil {
debugLogReqError(r, "Validate Response", false, r.Error)
return r.Error
}
debugLogReqError(r, "Validate Response", true, err)
continue
}
r.Handlers.Unmarshal.Run(r)
if r.Error != nil {
err := r.Error
r.Handlers.Retry.Run(r)
r.Handlers.AfterRetry.Run(r)
if r.Error != nil {
debugLogReqError(r, "Unmarshal Response", false, r.Error)
return r.Error
}
debugLogReqError(r, "Unmarshal Response", true, err)
continue
}
break
}
return nil
}
// WillRetry returns if the request's can be retried.
func (r *Request) WillRetry() bool {
return r.Error != nil && aws.BoolValue(r.Retryable) && r.RetryCount < r.MaxRetries()
}