From de6d2c524430287c699aaa898c1325da6afea539 Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Wed, 20 Jun 2018 22:39:07 +0100 Subject: Update dependencies --- vendor/go.opencensus.io/plugin/ochttp/trace.go | 199 +++++++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 vendor/go.opencensus.io/plugin/ochttp/trace.go (limited to 'vendor/go.opencensus.io/plugin/ochttp/trace.go') diff --git a/vendor/go.opencensus.io/plugin/ochttp/trace.go b/vendor/go.opencensus.io/plugin/ochttp/trace.go new file mode 100644 index 0000000..79bbfd1 --- /dev/null +++ b/vendor/go.opencensus.io/plugin/ochttp/trace.go @@ -0,0 +1,199 @@ +// Copyright 2018, OpenCensus Authors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package ochttp + +import ( + "io" + "net/http" + "net/url" + + "go.opencensus.io/plugin/ochttp/propagation/b3" + "go.opencensus.io/trace" + "go.opencensus.io/trace/propagation" +) + +// TODO(jbd): Add godoc examples. + +var defaultFormat propagation.HTTPFormat = &b3.HTTPFormat{} + +// Attributes recorded on the span for the requests. +// Only trace exporters will need them. +const ( + HostAttribute = "http.host" + MethodAttribute = "http.method" + PathAttribute = "http.path" + UserAgentAttribute = "http.user_agent" + StatusCodeAttribute = "http.status_code" +) + +type traceTransport struct { + base http.RoundTripper + startOptions trace.StartOptions + format propagation.HTTPFormat +} + +// TODO(jbd): Add message events for request and response size. + +// RoundTrip creates a trace.Span and inserts it into the outgoing request's headers. +// The created span can follow a parent span, if a parent is presented in +// the request's context. +func (t *traceTransport) RoundTrip(req *http.Request) (*http.Response, error) { + name := spanNameFromURL(req.URL) + // TODO(jbd): Discuss whether we want to prefix + // outgoing requests with Sent. + _, span := trace.StartSpan(req.Context(), name, + trace.WithSampler(t.startOptions.Sampler), + trace.WithSpanKind(trace.SpanKindClient)) + + req = req.WithContext(trace.WithSpan(req.Context(), span)) + if t.format != nil { + t.format.SpanContextToRequest(span.SpanContext(), req) + } + + span.AddAttributes(requestAttrs(req)...) + resp, err := t.base.RoundTrip(req) + if err != nil { + span.SetStatus(trace.Status{Code: trace.StatusCodeUnknown, Message: err.Error()}) + span.End() + return resp, err + } + + span.AddAttributes(responseAttrs(resp)...) + span.SetStatus(TraceStatus(resp.StatusCode, resp.Status)) + + // span.End() will be invoked after + // a read from resp.Body returns io.EOF or when + // resp.Body.Close() is invoked. + resp.Body = &bodyTracker{rc: resp.Body, span: span} + return resp, err +} + +// bodyTracker wraps a response.Body and invokes +// trace.EndSpan on encountering io.EOF on reading +// the body of the original response. +type bodyTracker struct { + rc io.ReadCloser + span *trace.Span +} + +var _ io.ReadCloser = (*bodyTracker)(nil) + +func (bt *bodyTracker) Read(b []byte) (int, error) { + n, err := bt.rc.Read(b) + + switch err { + case nil: + return n, nil + case io.EOF: + bt.span.End() + default: + // For all other errors, set the span status + bt.span.SetStatus(trace.Status{ + // Code 2 is the error code for Internal server error. + Code: 2, + Message: err.Error(), + }) + } + return n, err +} + +func (bt *bodyTracker) Close() error { + // Invoking endSpan on Close will help catch the cases + // in which a read returned a non-nil error, we set the + // span status but didn't end the span. + bt.span.End() + return bt.rc.Close() +} + +// CancelRequest cancels an in-flight request by closing its connection. +func (t *traceTransport) CancelRequest(req *http.Request) { + type canceler interface { + CancelRequest(*http.Request) + } + if cr, ok := t.base.(canceler); ok { + cr.CancelRequest(req) + } +} + +func spanNameFromURL(u *url.URL) string { + return u.Path +} + +func requestAttrs(r *http.Request) []trace.Attribute { + return []trace.Attribute{ + trace.StringAttribute(PathAttribute, r.URL.Path), + trace.StringAttribute(HostAttribute, r.URL.Host), + trace.StringAttribute(MethodAttribute, r.Method), + trace.StringAttribute(UserAgentAttribute, r.UserAgent()), + } +} + +func responseAttrs(resp *http.Response) []trace.Attribute { + return []trace.Attribute{ + trace.Int64Attribute(StatusCodeAttribute, int64(resp.StatusCode)), + } +} + +// TraceStatus converts the HTTP status code to a trace.Status that +// represents the outcome as closely as possible. +func TraceStatus(httpStatusCode int, statusLine string) trace.Status { + var code int32 + if httpStatusCode < 200 || httpStatusCode >= 400 { + code = trace.StatusCodeUnknown + } + switch httpStatusCode { + case 499: + code = trace.StatusCodeCancelled + case http.StatusBadRequest: + code = trace.StatusCodeInvalidArgument + case http.StatusGatewayTimeout: + code = trace.StatusCodeDeadlineExceeded + case http.StatusNotFound: + code = trace.StatusCodeNotFound + case http.StatusForbidden: + code = trace.StatusCodePermissionDenied + case http.StatusUnauthorized: // 401 is actually unauthenticated. + code = trace.StatusCodeUnauthenticated + case http.StatusTooManyRequests: + code = trace.StatusCodeResourceExhausted + case http.StatusNotImplemented: + code = trace.StatusCodeUnimplemented + case http.StatusServiceUnavailable: + code = trace.StatusCodeUnavailable + case http.StatusOK: + code = trace.StatusCodeOK + } + return trace.Status{Code: code, Message: codeToStr[code]} +} + +var codeToStr = map[int32]string{ + trace.StatusCodeOK: `"OK"`, + trace.StatusCodeCancelled: `"CANCELLED"`, + trace.StatusCodeUnknown: `"UNKNOWN"`, + trace.StatusCodeInvalidArgument: `"INVALID_ARGUMENT"`, + trace.StatusCodeDeadlineExceeded: `"DEADLINE_EXCEEDED"`, + trace.StatusCodeNotFound: `"NOT_FOUND"`, + trace.StatusCodeAlreadyExists: `"ALREADY_EXISTS"`, + trace.StatusCodePermissionDenied: `"PERMISSION_DENIED"`, + trace.StatusCodeResourceExhausted: `"RESOURCE_EXHAUSTED"`, + trace.StatusCodeFailedPrecondition: `"FAILED_PRECONDITION"`, + trace.StatusCodeAborted: `"ABORTED"`, + trace.StatusCodeOutOfRange: `"OUT_OF_RANGE"`, + trace.StatusCodeUnimplemented: `"UNIMPLEMENTED"`, + trace.StatusCodeInternal: `"INTERNAL"`, + trace.StatusCodeUnavailable: `"UNAVAILABLE"`, + trace.StatusCodeDataLoss: `"DATA_LOSS"`, + trace.StatusCodeUnauthenticated: `"UNAUTHENTICATED"`, +} -- cgit v1.2.3