feat: standardize OpenTelemetry HTTP span names to include method and route pattern

CHANGELOG.md

@@ -1,3 +1,6 @@
+# v0.12.0
+* feat: Add support for excluding HTTP request paths from logging using configurable regular expressions.
+
 # v0.11.1:
 * docs: Add comprehensive package-level documentation for the `http` package.
 * docs: Improve documentation for the `InitHTTPServer` function.

pkg/config/config.go

@@ -10,6 +10,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"regexp"
 	"runtime/debug"
 	"time"
 
@@ -105,6 +106,12 @@ func prepareConfig(cfg *AppConfig) error {
 		}
 	}
 
+	// Prepare user-provided expressions, panic up-front if invalid
+	cfg.HTTP.excludeRegexps = make([]*regexp.Regexp, len(cfg.HTTP.LogExcludePathRegexps))
+	for i, re := range cfg.HTTP.LogExcludePathRegexps {
+		cfg.HTTP.excludeRegexps[i] = regexp.MustCompile(re)
+	}
+
 	return errs
 }
 

pkg/config/types_http.go

@@ -1,6 +1,10 @@
 package config
 
-import "time"
+import (
+	"regexp"
+	"sync"
+	"time"
+)
 
 var defaultHTTPConfig = &HTTPConfig{
 	Enabled: true,
@@ -17,10 +21,20 @@ type HTTPConfig struct {
 	Enabled               bool     `yaml:"enabled" env:"APP_HTTP_ENABLED" json:"enabled,omitempty"`
 	Listen                string   `yaml:"listen,omitempty" env:"APP_HTTP_LISTEN" json:"listen,omitempty"`
 	LogRequests           bool     `yaml:"logRequests" env:"APP_HTTP_LOG_REQUESTS" json:"logRequests,omitempty"`
+	LogExcludePathRegexps []string `yaml:"logExcludePathRegexps" env:"APP_HTTP_LOG_EXCLUDE_PATH_REGEXPS" json:"logExcludePathRegexps,omitempty"`
 	ReadTimeout           string   `yaml:"readTimeout" env:"APP_HTTP_READ_TIMEOUT" json:"readTimeout,omitempty"`    // Go duration (e.g. 10s)
 	WriteTimeout          string   `yaml:"writeTimeout" env:"APP_HTTP_WRITE_TIMEOUT" json:"writeTimeout,omitempty"` // Go duration (e.g. 10s)
 	IdleTimeout           string   `yaml:"idleTimeout" env:"APP_HTTP_IDLE_TIMEOUT" json:"idleTimeout,omitempty"`    // Go duration (e.g. 10s)
+	excludeRegexps        []*regexp.Regexp
 	rT                    *time.Duration
 	wT                    *time.Duration
 	iT                    *time.Duration
+	lock                  sync.RWMutex
+}
+
+func (h *HTTPConfig) GetExcludeRegexps() []*regexp.Regexp {
+	h.lock.RLock()
+	defer h.lock.RUnlock()
+
+	return h.excludeRegexps
 }

pkg/srv/http/http.go

@@ -10,6 +10,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"regexp"
 	"strings"
 	"time"
 
@@ -27,6 +28,7 @@ import (
 var (
 	httpMeter                   metric.Meter
 	httpTracer                  trace.Tracer
+	httpPatternWithMethodRegexp = regexp.MustCompile(`(\w+) .*`)
 	defReadTimeout              = 10 * time.Second
 	defWriteTimeout             = 10 * time.Second
 	defIdleTimeout              = 15 * time.Second
@@ -39,19 +41,12 @@ func prepHTTPServer(opts *opts.AppHTTP) *http.Server {
 		mux = &http.ServeMux{}
 	)
 
-	// NOTE: Wraps handle func with otelhttp handler and
-	// inserts route tag
-	otelHandleFunc := func(pattern string, handlerFunc func(http.ResponseWriter, *http.Request)) {
-		handler := otelhttp.WithRouteTag(pattern, http.HandlerFunc(handlerFunc))
-		mux.Handle(pattern, handler) // Associate pattern with handler
-	}
-
 	healthChecks := handleHealthCheckFunc(opts.Ctx, opts.HealthChecks...)
-	otelHandleFunc("/health", healthChecks)
-	otelHandleFunc("/", healthChecks)
+	mux.HandleFunc("/health", healthChecks)
+	mux.HandleFunc("/", healthChecks)
 
 	for _, f := range opts.Funcs {
-		otelHandleFunc(f.Path, f.HandlerFunc)
+		mux.HandleFunc(f.Path, f.HandlerFunc)
 	}
 
 	// Prometheus metrics endpoint
@@ -74,12 +69,12 @@ func prepHTTPServer(opts *opts.AppHTTP) *http.Server {
 		if h.StripPrefix {
 			h.Handler = http.StripPrefix(h.Prefix[:len(h.Prefix)-1], h.Handler)
 		}
-		mux.Handle(h.Prefix, h.Handler)
+		mux.Handle(h.Prefix, otelhttp.WithRouteTag(h.Prefix, h.Handler))
 	}
 
-	// Add OTEL, skip health-check spans
-	// NOTE: Add any other span exclusions here
+	// Add OTEL instrumentation, filter noise, set span names
 	handler := otelhttp.NewHandler(mux, "/",
+		// TODO: Make configurable similar to config.http.LogExcludePathRegexps
 		otelhttp.WithFilter(func(r *http.Request) bool {
 			switch r.URL.Path {
 			case "/health":
@@ -89,6 +84,18 @@ func prepHTTPServer(opts *opts.AppHTTP) *http.Server {
 			default:
 				return true
 			}
+		}),
+		otelhttp.WithSpanNameFormatter(func(operation string, r *http.Request) string {
+			endpoint := r.URL.Path
+			if _, pattern := mux.Handler(r); pattern != "" {
+				endpoint = pattern
+			}
+
+			if httpPatternWithMethodRegexp.MatchString(endpoint) {
+				return endpoint
+			}
+
+			return fmt.Sprintf("%s %s", r.Method, endpoint)
 		}))
 
 	// Set timeouts from defaults, override

pkg/srv/http/http_log.go

@@ -10,6 +10,8 @@ import (
 	"time"
 
 	"github.com/rs/zerolog"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
 )
 
 var ExcludeFromLogging = regexp.MustCompile(`\/(ready|live|metrics)$`)
@@ -21,12 +23,22 @@ type LoggingResponseWriter struct {
 }
 
 func loggingMiddleware(appCtx context.Context, next http.Handler) http.Handler {
+	appConfig := config.MustFromCtx(appCtx)
+
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if ExcludeFromLogging.Match([]byte(r.URL.Path)) {
 			next.ServeHTTP(w, r)
 			return
 		}
 
+		// User-configurable logging exclusions
+		for _, re := range appConfig.HTTP.GetExcludeRegexps() {
+			if re.MatchString(r.URL.Path) {
+				next.ServeHTTP(w, r)
+				return
+			}
+		}
+
 		log := zerolog.Ctx(appCtx)
 
 		start := time.Now()