Documentation ¶
Overview ¶
Package runtime contains runtime helper functions used by servers which protoc-gen-grpc-gateway generates.
Index ¶
- Constants
- Variables
- func AnnotateContext(ctx context.Context, mux *ServeMux, req *http.Request) (context.Context, error)
- func Bool(val string) (bool, error)
- func BoolP(val string) (*bool, error)
- func BoolSlice(val, sep string) ([]bool, error)
- func BoolValue(val string) (*wrappers.BoolValue, error)
- func Bytes(val string) ([]byte, error)
- func BytesSlice(val, sep string) ([][]byte, error)
- func BytesValue(val string) (*wrappers.BytesValue, error)
- func CamelCaseFieldMask(mask *field_mask.FieldMask)
- func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, ...)
- func DefaultHTTPProtoErrorHandler(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, ...)
- func DefaultHeaderMatcher(key string) (string, bool)
- func DefaultOtherErrorHandler(w http.ResponseWriter, _ *http.Request, msg string, code int)
- func DoubleValue(val string) (*wrappers.DoubleValue, error)
- func Duration(val string) (*duration.Duration, error)
- func Enum(val string, enumValMap map[string]int32) (int32, error)
- func EnumSlice(val, sep string, enumValMap map[string]int32) ([]int32, error)
- func FieldMaskFromRequestBody(r io.Reader) (*field_mask.FieldMask, error)
- func Float32(val string) (float32, error)
- func Float32P(val string) (*float32, error)
- func Float32Slice(val, sep string) ([]float32, error)
- func Float64(val string) (float64, error)
- func Float64P(val string) (*float64, error)
- func Float64Slice(val, sep string) ([]float64, error)
- func FloatValue(val string) (*wrappers.FloatValue, error)
- func ForwardResponseMessage(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, ...)
- func ForwardResponseStream(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, ...)
- func HTTPStatusFromCode(code codes.Code) int
- func Int32(val string) (int32, error)
- func Int32P(val string) (*int32, error)
- func Int32Slice(val, sep string) ([]int32, error)
- func Int32Value(val string) (*wrappers.Int32Value, error)
- func Int64(val string) (int64, error)
- func Int64P(val string) (*int64, error)
- func Int64Slice(val, sep string) ([]int64, error)
- func Int64Value(val string) (*wrappers.Int64Value, error)
- func MarshalerForRequest(mux *ServeMux, r *http.Request) (inbound Marshaler, outbound Marshaler)
- func NewServerMetadataContext(ctx context.Context, md ServerMetadata) context.Context
- func PopulateFieldFromPath(msg proto.Message, fieldPathString string, value string) error
- func PopulateQueryParameters(msg proto.Message, values url.Values, filter *utilities.DoubleArray) error
- func String(val string) (string, error)
- func StringP(val string) (*string, error)
- func StringSlice(val, sep string) ([]string, error)
- func StringValue(val string) (*wrappers.StringValue, error)
- func Timestamp(val string) (*timestamp.Timestamp, error)
- func UInt32Value(val string) (*wrappers.UInt32Value, error)
- func UInt64Value(val string) (*wrappers.UInt64Value, error)
- func Uint32(val string) (uint32, error)
- func Uint32P(val string) (*uint32, error)
- func Uint32Slice(val, sep string) ([]uint32, error)
- func Uint64(val string) (uint64, error)
- func Uint64P(val string) (*uint64, error)
- func Uint64Slice(val, sep string) ([]uint64, error)
- type Decoder
- type DecoderFunc
- type DecoderWrapper
- type Delimited
- type Encoder
- type EncoderFunc
- type HandlerFunc
- type HeaderMatcherFunc
- type JSONBuiltin
- func (*JSONBuiltin) ContentType() string
- func (j *JSONBuiltin) Delimiter() []byte
- func (j *JSONBuiltin) Marshal(v interface{}) ([]byte, error)
- func (j *JSONBuiltin) NewDecoder(r io.Reader) Decoder
- func (j *JSONBuiltin) NewEncoder(w io.Writer) Encoder
- func (j *JSONBuiltin) Unmarshal(data []byte, v interface{}) error
- type JSONPb
- type Marshaler
- type Pattern
- type ProtoErrorHandlerFunc
- type ProtoMarshaller
- func (*ProtoMarshaller) ContentType() string
- func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error)
- func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder
- func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder
- func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error
- type ServeMux
- type ServeMuxOption
- func WithForwardResponseOption(...) ServeMuxOption
- func WithIncomingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption
- func WithMarshalerOption(mime string, marshaler Marshaler) ServeMuxOption
- func WithMetadata(annotator func(context.Context, *http.Request) metadata.MD) ServeMuxOption
- func WithOutgoingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption
- func WithProtoErrorHandler(fn ProtoErrorHandlerFunc) ServeMuxOption
- type ServerMetadata
Constants ¶
const MIMEWildcard = "*"
MIMEWildcard is the fallback MIME type used for requests which do not match a registered MIME type.
const MetadataHeaderPrefix = "Grpc-Metadata-"
MetadataHeaderPrefix is the http prefix that represents custom metadata parameters to or from a gRPC call.
const MetadataPrefix = "grpcgateway-"
MetadataPrefix is prepended to permanent HTTP header keys (as specified by the IANA) when added to the gRPC context.
const MetadataTrailerPrefix = "Grpc-Trailer-"
MetadataTrailerPrefix is prepended to gRPC metadata as it is converted to HTTP headers in a response handled by grpc-gateway
Variables ¶
var ( // HTTPError replies to the request with the error. // You can set a custom function to this variable to customize error format. HTTPError = DefaultHTTPError // OtherErrorHandler handles the following error used by the gateway: StatusMethodNotAllowed StatusNotFound and StatusBadRequest OtherErrorHandler = DefaultOtherErrorHandler )
var ( // ErrNotMatch indicates that the given HTTP request path does not match to the pattern. ErrNotMatch = errors.New("not match to the path pattern") // ErrInvalidPattern indicates that the given definition of Pattern is not valid. ErrInvalidPattern = errors.New("invalid pattern") )
var ( // DefaultContextTimeout is used for gRPC call context.WithTimeout whenever a Grpc-Timeout inbound // header isn't present. If the value is 0 the sent `context` will not have a timeout. DefaultContextTimeout = 0 * time.Second )
Functions ¶
func AnnotateContext ¶
func AnnotateContext(ctx context.Context, mux *ServeMux, req *http.Request) (context.Context, error)
AnnotateContext adds context information such as metadata from the request.
At a minimum, the RemoteAddr is included in the fashion of "X-Forwarded-For", except that the forwarded destination is not another HTTP service but rather a gRPC service.
func BoolP ¶
BoolP parses the given string representation of a boolean value, and returns a pointer to a bool whose value is same as the parsed value.
func BoolSlice ¶ added in v1.5.0
BoolSlice converts 'val' where individual booleans are separated by 'sep' into a bool slice.
func Bytes ¶ added in v1.4.0
Bytes converts the given string representation of a byte sequence into a slice of bytes A bytes sequence is encoded in URL-safe base64 without padding
func BytesSlice ¶ added in v1.5.0
BytesSlice converts 'val' where individual bytes sequences, encoded in URL-safe base64 without padding, are separated by 'sep' into a slice of bytes slices slice.
func BytesValue ¶ added in v1.6.0
func BytesValue(val string) (*wrappers.BytesValue, error)
BytesValue well-known type support as wrapper around bytes[] type
func CamelCaseFieldMask ¶ added in v1.6.0
func CamelCaseFieldMask(mask *field_mask.FieldMask)
CamelCaseFieldMask updates the given FieldMask by converting all of its paths to CamelCase, using the same heuristic that's used for naming protobuf fields in Go.
func DefaultHTTPError ¶
func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error)
DefaultHTTPError is the default implementation of HTTPError. If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode. If otherwise, it replies with http.StatusInternalServerError.
The response body returned by this function is a JSON object, which contains a member whose key is "error" and whose value is err.Error().
func DefaultHTTPProtoErrorHandler ¶ added in v1.3.0
func DefaultHTTPProtoErrorHandler(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error)
DefaultHTTPProtoErrorHandler is an implementation of HTTPError. If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode. If otherwise, it replies with http.StatusInternalServerError.
The response body returned by this function is a Status message marshaled by a Marshaler.
Do not set this function to HTTPError variable directly, use WithProtoErrorHandler option instead.
func DefaultHeaderMatcher ¶ added in v1.3.0
DefaultHeaderMatcher is used to pass http request headers to/from gRPC context. This adds permanent HTTP header keys (as specified by the IANA) to gRPC context with grpcgateway- prefix. HTTP headers that start with 'Grpc-Metadata-' are mapped to gRPC metadata after removing prefix 'Grpc-Metadata-'.
func DefaultOtherErrorHandler ¶
DefaultOtherErrorHandler is the default implementation of OtherErrorHandler. It simply writes a string representation of the given error into "w".
func DoubleValue ¶ added in v1.6.0
func DoubleValue(val string) (*wrappers.DoubleValue, error)
DoubleValue well-known type support as wrapper around float64 type
func Enum ¶ added in v1.5.0
Enum converts the given string into an int32 that should be type casted into the correct enum proto type.
func EnumSlice ¶ added in v1.5.0
EnumSlice converts 'val' where individual enums are separated by 'sep' into a int32 slice. Each individual int32 should be type casted into the correct enum proto type.
func FieldMaskFromRequestBody ¶ added in v1.6.0
func FieldMaskFromRequestBody(r io.Reader) (*field_mask.FieldMask, error)
FieldMaskFromRequestBody creates a FieldMask printing all complete paths from the JSON body.
func Float32 ¶
Float32 converts the given string representation of a floating point number into float32.
func Float32P ¶
Float32P parses the given string representation of a floating point number, and returns a pointer to a float32 whose value is same as the parsed number.
func Float32Slice ¶ added in v1.5.0
Float32Slice converts 'val' where individual floating point numbers are separated by 'sep' into a float32 slice.
func Float64 ¶
Float64 converts the given string representation into representation of a floating point number into float64.
func Float64P ¶
Float64P parses the given string representation of a floating point number, and returns a pointer to a float64 whose value is same as the parsed number.
func Float64Slice ¶ added in v1.5.0
Float64Slice converts 'val' where individual floating point numbers are separated by 'sep' into a float64 slice.
func FloatValue ¶ added in v1.6.0
func FloatValue(val string) (*wrappers.FloatValue, error)
FloatValue well-known type support as wrapper around float32 type
func ForwardResponseMessage ¶
func ForwardResponseMessage(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, req *http.Request, resp proto.Message, opts ...func(context.Context, http.ResponseWriter, proto.Message) error)
ForwardResponseMessage forwards the message "resp" from gRPC server to REST client.
func ForwardResponseStream ¶
func ForwardResponseStream(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, req *http.Request, recv func() (proto.Message, error), opts ...func(context.Context, http.ResponseWriter, proto.Message) error)
ForwardResponseStream forwards the stream from gRPC server to REST client.
func HTTPStatusFromCode ¶
HTTPStatusFromCode converts a gRPC error code into the corresponding HTTP response status. See: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
func Int32P ¶
Int32P parses the given string representation of an integer and returns a pointer to a int32 whose value is same as the parsed integer.
func Int32Slice ¶ added in v1.5.0
Int32Slice converts 'val' where individual integers are separated by 'sep' into a int32 slice.
func Int32Value ¶ added in v1.6.0
func Int32Value(val string) (*wrappers.Int32Value, error)
Int32Value well-known type support as wrapper around int32 type
func Int64P ¶
Int64P parses the given string representation of an integer and returns a pointer to a int64 whose value is same as the parsed integer.
func Int64Slice ¶ added in v1.5.0
Int64Slice converts 'val' where individual integers are separated by 'sep' into a int64 slice.
func Int64Value ¶ added in v1.6.0
func Int64Value(val string) (*wrappers.Int64Value, error)
Int64Value well-known type support as wrapper around int64 type
func MarshalerForRequest ¶
MarshalerForRequest returns the inbound/outbound marshalers for this request. It checks the registry on the ServeMux for the MIME type set by the Content-Type header. If it isn't set (or the request Content-Type is empty), checks for "*". If there are multiple Content-Type headers set, choose the first one that it can exactly match in the registry. Otherwise, it follows the above logic for "*"/InboundMarshaler/OutboundMarshaler.
func NewServerMetadataContext ¶
func NewServerMetadataContext(ctx context.Context, md ServerMetadata) context.Context
NewServerMetadataContext creates a new context with ServerMetadata
func PopulateFieldFromPath ¶
PopulateFieldFromPath sets a value in a nested Protobuf structure. It instantiates missing protobuf fields as it goes.
func PopulateQueryParameters ¶
func PopulateQueryParameters(msg proto.Message, values url.Values, filter *utilities.DoubleArray) error
PopulateQueryParameters populates "values" into "msg". A value is ignored if its key starts with one of the elements in "filter".
func StringP ¶
StringP returns a pointer to a string whose pointee is same as the given string value.
func StringSlice ¶ added in v1.5.0
StringSlice converts 'val' where individual strings are separated by 'sep' into a string slice.
func StringValue ¶ added in v1.6.0
func StringValue(val string) (*wrappers.StringValue, error)
StringValue well-known type support as wrapper around string type
func Timestamp ¶ added in v1.3.1
Timestamp converts the given RFC3339 formatted string into a timestamp.Timestamp.
func UInt32Value ¶ added in v1.6.0
func UInt32Value(val string) (*wrappers.UInt32Value, error)
UInt32Value well-known type support as wrapper around uint32 type
func UInt64Value ¶ added in v1.6.0
func UInt64Value(val string) (*wrappers.UInt64Value, error)
UInt64Value well-known type support as wrapper around uint64 type
func Uint32P ¶
Uint32P parses the given string representation of an integer and returns a pointer to a uint32 whose value is same as the parsed integer.
func Uint32Slice ¶ added in v1.5.0
Uint32Slice converts 'val' where individual integers are separated by 'sep' into a uint32 slice.
func Uint64P ¶
Uint64P parses the given string representation of an integer and returns a pointer to a uint64 whose value is same as the parsed integer.
func Uint64Slice ¶ added in v1.5.0
Uint64Slice converts 'val' where individual integers are separated by 'sep' into a uint64 slice.
Types ¶
type Decoder ¶
type Decoder interface {
Decode(v interface{}) error
}
Decoder decodes a byte sequence
type DecoderFunc ¶
type DecoderFunc func(v interface{}) error
DecoderFunc adapts an decoder function into Decoder.
func (DecoderFunc) Decode ¶
func (f DecoderFunc) Decode(v interface{}) error
Decode delegates invocations to the underlying function itself.
type DecoderWrapper ¶ added in v1.4.0
DecoderWrapper is a wrapper around a *json.Decoder that adds support for protos to the Decode method.
func (DecoderWrapper) Decode ¶ added in v1.4.0
func (d DecoderWrapper) Decode(v interface{}) error
Decode wraps the embedded decoder's Decode method to support protos using a jsonpb.Unmarshaler.
type Delimited ¶ added in v1.3.1
type Delimited interface { // Delimiter returns the record seperator for the stream. Delimiter() []byte }
Delimited defines the streaming delimiter.
type Encoder ¶
type Encoder interface {
Encode(v interface{}) error
}
Encoder encodes gRPC payloads / fields into byte sequence.
type EncoderFunc ¶
type EncoderFunc func(v interface{}) error
EncoderFunc adapts an encoder function into Encoder
func (EncoderFunc) Encode ¶
func (f EncoderFunc) Encode(v interface{}) error
Encode delegates invocations to the underlying function itself.
type HandlerFunc ¶
A HandlerFunc handles a specific pair of path pattern and HTTP method.
type HeaderMatcherFunc ¶ added in v1.3.0
HeaderMatcherFunc checks whether a header key should be forwarded to/from gRPC context.
type JSONBuiltin ¶
type JSONBuiltin struct{}
JSONBuiltin is a Marshaler which marshals/unmarshals into/from JSON with the standard "encoding/json" package of Golang. Although it is generally faster for simple proto messages than JSONPb, it does not support advanced features of protobuf, e.g. map, oneof, ....
The NewEncoder and NewDecoder types return *json.Encoder and *json.Decoder respectively.
func (*JSONBuiltin) ContentType ¶
func (*JSONBuiltin) ContentType() string
ContentType always Returns "application/json".
func (*JSONBuiltin) Delimiter ¶ added in v1.3.1
func (j *JSONBuiltin) Delimiter() []byte
Delimiter for newline encoded JSON streams.
func (*JSONBuiltin) Marshal ¶
func (j *JSONBuiltin) Marshal(v interface{}) ([]byte, error)
Marshal marshals "v" into JSON
func (*JSONBuiltin) NewDecoder ¶
func (j *JSONBuiltin) NewDecoder(r io.Reader) Decoder
NewDecoder returns a Decoder which reads JSON stream from "r".
func (*JSONBuiltin) NewEncoder ¶
func (j *JSONBuiltin) NewEncoder(w io.Writer) Encoder
NewEncoder returns an Encoder which writes JSON stream into "w".
func (*JSONBuiltin) Unmarshal ¶
func (j *JSONBuiltin) Unmarshal(data []byte, v interface{}) error
Unmarshal unmarshals JSON data into "v".
type JSONPb ¶
JSONPb is a Marshaler which marshals/unmarshals into/from JSON with the "github.com/golang/protobuf/jsonpb". It supports fully functionality of protobuf unlike JSONBuiltin.
The NewDecoder method returns a DecoderWrapper, so the underlying *json.Decoder methods can be used.
func (*JSONPb) ContentType ¶
ContentType always returns "application/json".
func (*JSONPb) NewDecoder ¶
NewDecoder returns a Decoder which reads JSON stream from "r".
func (*JSONPb) NewEncoder ¶
NewEncoder returns an Encoder which writes JSON stream into "w".
type Marshaler ¶
type Marshaler interface { // Marshal marshals "v" into byte sequence. Marshal(v interface{}) ([]byte, error) // Unmarshal unmarshals "data" into "v". // "v" must be a pointer value. Unmarshal(data []byte, v interface{}) error // NewDecoder returns a Decoder which reads byte sequence from "r". NewDecoder(r io.Reader) Decoder // NewEncoder returns an Encoder which writes bytes sequence into "w". NewEncoder(w io.Writer) Encoder // ContentType returns the Content-Type which this marshaler is responsible for. ContentType() string }
Marshaler defines a conversion between byte sequence and gRPC payloads / fields.
type Pattern ¶
type Pattern struct {
// contains filtered or unexported fields
}
Pattern is a template pattern of http request paths defined in github.com/googleapis/googleapis/google/api/http.proto.
func MustPattern ¶
MustPattern is a helper function which makes it easier to call NewPattern in variable initialization.
func NewPattern ¶
NewPattern returns a new Pattern from the given definition values. "ops" is a sequence of op codes. "pool" is a constant pool. "verb" is the verb part of the pattern. It is empty if the pattern does not have the part. "version" must be 1 for now. It returns an error if the given definition is invalid.
type ProtoErrorHandlerFunc ¶ added in v1.3.0
type ProtoErrorHandlerFunc func(context.Context, *ServeMux, Marshaler, http.ResponseWriter, *http.Request, error)
ProtoErrorHandlerFunc handles the error as a gRPC error generated via status package and replies to the request.
type ProtoMarshaller ¶ added in v1.3.1
type ProtoMarshaller struct{}
ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
func (*ProtoMarshaller) ContentType ¶ added in v1.3.1
func (*ProtoMarshaller) ContentType() string
ContentType always returns "application/octet-stream".
func (*ProtoMarshaller) Marshal ¶ added in v1.3.1
func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error)
Marshal marshals "value" into Proto
func (*ProtoMarshaller) NewDecoder ¶ added in v1.3.1
func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder
NewDecoder returns a Decoder which reads proto stream from "reader".
func (*ProtoMarshaller) NewEncoder ¶ added in v1.3.1
func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder
NewEncoder returns an Encoder which writes proto stream into "writer".
func (*ProtoMarshaller) Unmarshal ¶ added in v1.3.1
func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error
Unmarshal unmarshals proto "data" into "value"
type ServeMux ¶
type ServeMux struct {
// contains filtered or unexported fields
}
ServeMux is a request multiplexer for grpc-gateway. It matches http requests to patterns and invokes the corresponding handler.
func NewServeMux ¶
func NewServeMux(opts ...ServeMuxOption) *ServeMux
NewServeMux returns a new ServeMux whose internal mapping is empty.
func (*ServeMux) GetForwardResponseOptions ¶
func (s *ServeMux) GetForwardResponseOptions() []func(context.Context, http.ResponseWriter, proto.Message) error
GetForwardResponseOptions returns the ForwardResponseOptions associated with this ServeMux.
type ServeMuxOption ¶
type ServeMuxOption func(*ServeMux)
ServeMuxOption is an option that can be given to a ServeMux on construction.
func WithForwardResponseOption ¶
func WithForwardResponseOption(forwardResponseOption func(context.Context, http.ResponseWriter, proto.Message) error) ServeMuxOption
WithForwardResponseOption returns a ServeMuxOption representing the forwardResponseOption.
forwardResponseOption is an option that will be called on the relevant context.Context, http.ResponseWriter, and proto.Message before every forwarded response.
The message may be nil in the case where just a header is being sent.
func WithIncomingHeaderMatcher ¶ added in v1.3.0
func WithIncomingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption
WithIncomingHeaderMatcher returns a ServeMuxOption representing a headerMatcher for incoming request to gateway.
This matcher will be called with each header in http.Request. If matcher returns true, that header will be passed to gRPC context. To transform the header before passing to gRPC context, matcher should return modified header.
func WithMarshalerOption ¶
func WithMarshalerOption(mime string, marshaler Marshaler) ServeMuxOption
WithMarshalerOption returns a ServeMuxOption which associates inbound and outbound Marshalers to a MIME type in mux.
func WithMetadata ¶ added in v1.3.0
WithMetadata returns a ServeMuxOption for passing metadata to a gRPC context.
This can be used by services that need to read from http.Request and modify gRPC context. A common use case is reading token from cookie and adding it in gRPC context.
func WithOutgoingHeaderMatcher ¶ added in v1.3.0
func WithOutgoingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption
WithOutgoingHeaderMatcher returns a ServeMuxOption representing a headerMatcher for outgoing response from gateway.
This matcher will be called with each header in response header metadata. If matcher returns true, that header will be passed to http response returned from gateway. To transform the header before passing to response, matcher should return modified header.
func WithProtoErrorHandler ¶ added in v1.3.0
func WithProtoErrorHandler(fn ProtoErrorHandlerFunc) ServeMuxOption
WithProtoErrorHandler returns a ServeMuxOption for passing metadata to a gRPC context.
This can be used to handle an error as general proto message defined by gRPC. The response including body and status is not backward compatible with the default error handler. When this option is used, HTTPError and OtherErrorHandler are overwritten on initialization.
type ServerMetadata ¶
ServerMetadata consists of metadata sent from gRPC server.
func ServerMetadataFromContext ¶
func ServerMetadataFromContext(ctx context.Context) (md ServerMetadata, ok bool)
ServerMetadataFromContext returns the ServerMetadata in ctx