[VOL-3196] Enhanced gRPC interfaces to create and propagate Span for log correlation
Change-Id: I8bbf2263a7090b73555027cc54ff5c55a66ee4fb
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/context.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/context.go
new file mode 100644
index 0000000..583025c
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/context.go
@@ -0,0 +1,78 @@
+package grpc_ctxtags
+
+import (
+ "context"
+)
+
+type ctxMarker struct{}
+
+var (
+ // ctxMarkerKey is the Context value marker used by *all* logging middleware.
+ // The logging middleware object must interf
+ ctxMarkerKey = &ctxMarker{}
+ // NoopTags is a trivial, minimum overhead implementation of Tags for which all operations are no-ops.
+ NoopTags = &noopTags{}
+)
+
+// Tags is the interface used for storing request tags between Context calls.
+// The default implementation is *not* thread safe, and should be handled only in the context of the request.
+type Tags interface {
+ // Set sets the given key in the metadata tags.
+ Set(key string, value interface{}) Tags
+ // Has checks if the given key exists.
+ Has(key string) bool
+ // Values returns a map of key to values.
+ // Do not modify the underlying map, please use Set instead.
+ Values() map[string]interface{}
+}
+
+type mapTags struct {
+ values map[string]interface{}
+}
+
+func (t *mapTags) Set(key string, value interface{}) Tags {
+ t.values[key] = value
+ return t
+}
+
+func (t *mapTags) Has(key string) bool {
+ _, ok := t.values[key]
+ return ok
+}
+
+func (t *mapTags) Values() map[string]interface{} {
+ return t.values
+}
+
+type noopTags struct{}
+
+func (t *noopTags) Set(key string, value interface{}) Tags {
+ return t
+}
+
+func (t *noopTags) Has(key string) bool {
+ return false
+}
+
+func (t *noopTags) Values() map[string]interface{} {
+ return nil
+}
+
+// Extracts returns a pre-existing Tags object in the Context.
+// If the context wasn't set in a tag interceptor, a no-op Tag storage is returned that will *not* be propagated in context.
+func Extract(ctx context.Context) Tags {
+ t, ok := ctx.Value(ctxMarkerKey).(Tags)
+ if !ok {
+ return NoopTags
+ }
+
+ return t
+}
+
+func setInContext(ctx context.Context, tags Tags) context.Context {
+ return context.WithValue(ctx, ctxMarkerKey, tags)
+}
+
+func newTags() Tags {
+ return &mapTags{values: make(map[string]interface{})}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/doc.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/doc.go
new file mode 100644
index 0000000..960638d
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/doc.go
@@ -0,0 +1,22 @@
+/*
+`grpc_ctxtags` adds a Tag object to the context that can be used by other middleware to add context about a request.
+
+Request Context Tags
+
+Tags describe information about the request, and can be set and used by other middleware, or handlers. Tags are used
+for logging and tracing of requests. Tags are populated both upwards, *and* downwards in the interceptor-handler stack.
+
+You can automatically extract tags (in `grpc.request.<field_name>`) from request payloads.
+
+For unary and server-streaming methods, pass in the `WithFieldExtractor` option. For client-streams and bidirectional-streams, you can
+use `WithFieldExtractorForInitialReq` which will extract the tags from the first message passed from client to server.
+Note the tags will not be modified for subsequent requests, so this option only makes sense when the initial message
+establishes the meta-data for the stream.
+
+If a user doesn't use the interceptors that initialize the `Tags` object, all operations following from an `Extract(ctx)`
+will be no-ops. This is to ensure that code doesn't panic if the interceptors weren't used.
+
+Tags fields are typed, and shallow and should follow the OpenTracing semantics convention:
+https://github.com/opentracing/specification/blob/master/semantic_conventions.md
+*/
+package grpc_ctxtags
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/fieldextractor.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/fieldextractor.go
new file mode 100644
index 0000000..549ff48
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/fieldextractor.go
@@ -0,0 +1,85 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_ctxtags
+
+import (
+ "reflect"
+)
+
+// RequestFieldExtractorFunc is a user-provided function that extracts field information from a gRPC request.
+// It is called from tags middleware on arrival of unary request or a server-stream request.
+// Keys and values will be added to the context tags of the request. If there are no fields, you should return a nil.
+type RequestFieldExtractorFunc func(fullMethod string, req interface{}) map[string]interface{}
+
+type requestFieldsExtractor interface {
+ // ExtractRequestFields is a method declared on a Protobuf message that extracts fields from the interface.
+ // The values from the extracted fields should be set in the appendToMap, in order to avoid allocations.
+ ExtractRequestFields(appendToMap map[string]interface{})
+}
+
+// CodeGenRequestFieldExtractor is a function that relies on code-generated functions that export log fields from requests.
+// These are usually coming from a protoc-plugin that generates additional information based on custom field options.
+func CodeGenRequestFieldExtractor(fullMethod string, req interface{}) map[string]interface{} {
+ if ext, ok := req.(requestFieldsExtractor); ok {
+ retMap := make(map[string]interface{})
+ ext.ExtractRequestFields(retMap)
+ if len(retMap) == 0 {
+ return nil
+ }
+ return retMap
+ }
+ return nil
+}
+
+// TagBasedRequestFieldExtractor is a function that relies on Go struct tags to export log fields from requests.
+// These are usually coming from a protoc-plugin, such as Gogo protobuf.
+//
+// message Metadata {
+// repeated string tags = 1 [ (gogoproto.moretags) = "log_field:\"meta_tags\"" ];
+// }
+//
+// The tagName is configurable using the tagName variable. Here it would be "log_field".
+func TagBasedRequestFieldExtractor(tagName string) RequestFieldExtractorFunc {
+ return func(fullMethod string, req interface{}) map[string]interface{} {
+ retMap := make(map[string]interface{})
+ reflectMessageTags(req, retMap, tagName)
+ if len(retMap) == 0 {
+ return nil
+ }
+ return retMap
+ }
+}
+
+func reflectMessageTags(msg interface{}, existingMap map[string]interface{}, tagName string) {
+ v := reflect.ValueOf(msg)
+ // Only deal with pointers to structs.
+ if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
+ return
+ }
+ // Deref the pointer get to the struct.
+ v = v.Elem()
+ t := v.Type()
+ for i := 0; i < v.NumField(); i++ {
+ field := v.Field(i)
+ kind := field.Kind()
+ // Only recurse down direct pointers, which should only be to nested structs.
+ if kind == reflect.Ptr {
+ reflectMessageTags(field.Interface(), existingMap, tagName)
+ }
+ // In case of arrays/splices (repeated fields) go down to the concrete type.
+ if kind == reflect.Array || kind == reflect.Slice {
+ if field.Len() == 0 {
+ continue
+ }
+ kind = field.Index(0).Kind()
+ }
+ // Only be interested in
+ if (kind >= reflect.Bool && kind <= reflect.Float64) || kind == reflect.String {
+ if tag := t.Field(i).Tag.Get(tagName); tag != "" {
+ existingMap[tag] = field.Interface()
+ }
+ }
+ }
+ return
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go
new file mode 100644
index 0000000..038afd2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go
@@ -0,0 +1,83 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_ctxtags
+
+import (
+ "github.com/grpc-ecosystem/go-grpc-middleware"
+ "golang.org/x/net/context"
+ "google.golang.org/grpc"
+ "google.golang.org/grpc/peer"
+)
+
+// UnaryServerInterceptor returns a new unary server interceptors that sets the values for request tags.
+func UnaryServerInterceptor(opts ...Option) grpc.UnaryServerInterceptor {
+ o := evaluateOptions(opts)
+ return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+ newCtx := newTagsForCtx(ctx)
+ if o.requestFieldsFunc != nil {
+ setRequestFieldTags(newCtx, o.requestFieldsFunc, info.FullMethod, req)
+ }
+ return handler(newCtx, req)
+ }
+}
+
+// StreamServerInterceptor returns a new streaming server interceptor that sets the values for request tags.
+func StreamServerInterceptor(opts ...Option) grpc.StreamServerInterceptor {
+ o := evaluateOptions(opts)
+ return func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+ newCtx := newTagsForCtx(stream.Context())
+ if o.requestFieldsFunc == nil {
+ // Short-circuit, don't do the expensive bit of allocating a wrappedStream.
+ wrappedStream := grpc_middleware.WrapServerStream(stream)
+ wrappedStream.WrappedContext = newCtx
+ return handler(srv, wrappedStream)
+ }
+ wrapped := &wrappedStream{stream, info, o, newCtx, true}
+ err := handler(srv, wrapped)
+ return err
+ }
+}
+
+// wrappedStream is a thin wrapper around grpc.ServerStream that allows modifying context and extracts log fields from the initial message.
+type wrappedStream struct {
+ grpc.ServerStream
+ info *grpc.StreamServerInfo
+ opts *options
+ // WrappedContext is the wrapper's own Context. You can assign it.
+ WrappedContext context.Context
+ initial bool
+}
+
+// Context returns the wrapper's WrappedContext, overwriting the nested grpc.ServerStream.Context()
+func (w *wrappedStream) Context() context.Context {
+ return w.WrappedContext
+}
+
+func (w *wrappedStream) RecvMsg(m interface{}) error {
+ err := w.ServerStream.RecvMsg(m)
+ // We only do log fields extraction on the single-request of a server-side stream.
+ if !w.info.IsClientStream || w.opts.requestFieldsFromInitial && w.initial {
+ w.initial = false
+
+ setRequestFieldTags(w.Context(), w.opts.requestFieldsFunc, w.info.FullMethod, m)
+ }
+ return err
+}
+
+func newTagsForCtx(ctx context.Context) context.Context {
+ t := newTags()
+ if peer, ok := peer.FromContext(ctx); ok {
+ t.Set("peer.address", peer.Addr.String())
+ }
+ return setInContext(ctx, t)
+}
+
+func setRequestFieldTags(ctx context.Context, f RequestFieldExtractorFunc, fullMethodName string, req interface{}) {
+ if valMap := f(fullMethodName, req); valMap != nil {
+ t := Extract(ctx)
+ for k, v := range valMap {
+ t.Set("grpc.request."+k, v)
+ }
+ }
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/options.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/options.go
new file mode 100644
index 0000000..952775f
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/options.go
@@ -0,0 +1,44 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_ctxtags
+
+var (
+ defaultOptions = &options{
+ requestFieldsFunc: nil,
+ }
+)
+
+type options struct {
+ requestFieldsFunc RequestFieldExtractorFunc
+ requestFieldsFromInitial bool
+}
+
+func evaluateOptions(opts []Option) *options {
+ optCopy := &options{}
+ *optCopy = *defaultOptions
+ for _, o := range opts {
+ o(optCopy)
+ }
+ return optCopy
+}
+
+type Option func(*options)
+
+// WithFieldExtractor customizes the function for extracting log fields from protobuf messages, for
+// unary and server-streamed methods only.
+func WithFieldExtractor(f RequestFieldExtractorFunc) Option {
+ return func(o *options) {
+ o.requestFieldsFunc = f
+ }
+}
+
+// WithFieldExtractorForInitialReq customizes the function for extracting log fields from protobuf messages,
+// for all unary and streaming methods. For client-streams and bidirectional-streams, the tags will be
+// extracted from the first message from the client.
+func WithFieldExtractorForInitialReq(f RequestFieldExtractorFunc) Option {
+ return func(o *options) {
+ o.requestFieldsFunc = f
+ o.requestFieldsFromInitial = true
+ }
+}