diff options
author | Andrii Kushch <andrii.kushch@gmail.com> | 2022-03-08 20:18:32 +0100 |
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committer | GitHub <noreply@github.com> | 2022-03-08 12:18:32 -0700 |
commit | d0b608af3178bc674936f4b1c6cce00591ebbf09 (patch) | |
tree | a8646d0d406acf98df62856815d4eae4d44cdd4f /modules/caddyhttp/tracing/tracer.go | |
parent | d9b1d463259a6f8f520edd6659dac11218c82b4e (diff) |
tracing: New OpenTelemetry module (#4361)
* opentelemetry: create a new module
* fix imports
* fix test
* Update modules/caddyhttp/opentelemetry/README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update modules/caddyhttp/opentelemetry/README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update modules/caddyhttp/opentelemetry/README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update modules/caddyhttp/opentelemetry/tracer.go
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* rename error ErrUnsupportedTracesProtocol
* replace spaces with tabs in the test data
* Update modules/caddyhttp/opentelemetry/README.md
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
* Update modules/caddyhttp/opentelemetry/README.md
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
* replace spaces with tabs in the README.md
* use default values for a propagation and exporter protocol
* set http attributes with helper
* simplify code
* Cleanup modules/caddyhttp/opentelemetry/README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update link in README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update documentation in README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update link to naming spec in README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Rename module from opentelemetry to tracing
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Rename span_name to span
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Rename span_name to span
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Simplify otel resource creation
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* handle extra attributes
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* update go.opentelemetry.io/otel/semconv to 1.7.0
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* update go.opentelemetry.io/otel version
* remove environment variable handling
* always use tracecontext,baggage as propagators
* extract tracer name into variable
* rename OpenTelemetry to Tracing
* simplify resource creation
* update go.mod
* rename package from opentelemetry to tracing
* cleanup tests
* update Caddyfile example in README.md
* update README.md
* fix test
* fix module name in README.md
* fix module name in README.md
* change names in README.md and tests
* order imports
* remove redundant tests
* Update documentation README.md
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Fix grammar
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update comments
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* Update comments
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
* update go.sum
* update go.sum
* Add otelhttp instrumentation, update OpenTelemetry libraries.
* Use otelhttp instrumentation for instrumenting HTTP requests.
This change uses context.WithValue to inject the next handler into the
request context via a "nextCall" carrier struct, and pass it on to a
standard Go HTTP handler returned by otelhttp.NewHandler. The
underlying handler will extract the next handler from the context,
call it and pass the returned error to the carrier struct.
* use zap.Error() for the error log
* remove README.md
* update dependencies
* clean up the code
* change comment
* move serveHTTP method from separate file
* add syntax to the UnmarshalCaddyfile comment
* go import the file
* admin: Write proper status on invalid requests (#4569) (fix #4561)
* update dependencies
Co-authored-by: Dave Henderson <dhenderson@gmail.com>
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
Co-authored-by: Vibhav Pant <vibhavp@gmail.com>
Co-authored-by: Alok Naushad <alokme123@gmail.com>
Co-authored-by: Cedric Ziel <cedric@cedric-ziel.com>
Diffstat (limited to 'modules/caddyhttp/tracing/tracer.go')
-rw-r--r-- | modules/caddyhttp/tracing/tracer.go | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/modules/caddyhttp/tracing/tracer.go b/modules/caddyhttp/tracing/tracer.go new file mode 100644 index 0000000..ce23944 --- /dev/null +++ b/modules/caddyhttp/tracing/tracer.go @@ -0,0 +1,108 @@ +package tracing + +import ( + "context" + "fmt" + "net/http" + + "github.com/caddyserver/caddy/v2" + + caddycmd "github.com/caddyserver/caddy/v2/cmd" + "github.com/caddyserver/caddy/v2/modules/caddyhttp" + "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp" + "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc" + "go.opentelemetry.io/otel/propagation" + "go.opentelemetry.io/otel/sdk/resource" + sdktrace "go.opentelemetry.io/otel/sdk/trace" + semconv "go.opentelemetry.io/otel/semconv/v1.7.0" + "go.uber.org/zap" +) + +const ( + webEngineName = "Caddy" + defaultSpanName = "handler" + nextCallCtxKey caddy.CtxKey = "nextCall" +) + +// nextCall store the next handler, and the error value return on calling it (if any) +type nextCall struct { + next caddyhttp.Handler + err error +} + +// openTelemetryWrapper is responsible for the tracing injection, extraction and propagation. +type openTelemetryWrapper struct { + propagators propagation.TextMapPropagator + + handler http.Handler + + spanName string +} + +// newOpenTelemetryWrapper is responsible for the openTelemetryWrapper initialization using provided configuration. +func newOpenTelemetryWrapper( + ctx context.Context, + spanName string, +) (openTelemetryWrapper, error) { + if spanName == "" { + spanName = defaultSpanName + } + + ot := openTelemetryWrapper{ + spanName: spanName, + } + + res, err := ot.newResource(webEngineName, caddycmd.CaddyVersion()) + if err != nil { + return ot, fmt.Errorf("creating resource error: %w", err) + } + + traceExporter, err := otlptracegrpc.New(ctx) + if err != nil { + return ot, fmt.Errorf("creating trace exporter error: %w", err) + } + + ot.propagators = propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}) + + tracerProvider := globalTracerProvider.getTracerProvider( + sdktrace.WithBatcher(traceExporter), + sdktrace.WithResource(res), + ) + + ot.handler = otelhttp.NewHandler(http.HandlerFunc(ot.serveHTTP), ot.spanName, otelhttp.WithTracerProvider(tracerProvider), otelhttp.WithPropagators(ot.propagators)) + return ot, nil +} + +// serveHTTP injects a tracing context and call the next handler. +func (ot *openTelemetryWrapper) serveHTTP(w http.ResponseWriter, r *http.Request) { + ot.propagators.Inject(r.Context(), propagation.HeaderCarrier(r.Header)) + next := r.Context().Value(nextCallCtxKey).(*nextCall) + next.err = next.next.ServeHTTP(w, r) +} + +// ServeHTTP propagates call to the by wrapped by `otelhttp` next handler. +func (ot *openTelemetryWrapper) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error { + n := &nextCall{ + next: next, + err: nil, + } + ot.handler.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), nextCallCtxKey, n))) + + return n.err +} + +// cleanup flush all remaining data and shutdown a tracerProvider +func (ot *openTelemetryWrapper) cleanup(logger *zap.Logger) error { + return globalTracerProvider.cleanupTracerProvider(logger) +} + +// newResource creates a resource that describe current handler instance and merge it with a default attributes value. +func (ot *openTelemetryWrapper) newResource( + webEngineName, + webEngineVersion string, +) (*resource.Resource, error) { + return resource.Merge(resource.Default(), resource.NewSchemaless( + semconv.WebEngineNameKey.String(webEngineName), + semconv.WebEngineVersionKey.String(webEngineVersion), + )) +} |