feat(lib): add log filtering rules

Closes #942

Signed-off-by: Xe Iaso <me@xeiaso.net>

internal/log.go

@@ -1,31 +1,10 @@
 package internal
 
 import (
-	"fmt"
-	"log"
 	"log/slog"
 	"net/http"
-	"os"
-	"strings"
 )
 
-func InitSlog(level string) {
-	var programLevel slog.Level
-	if err := (&programLevel).UnmarshalText([]byte(level)); err != nil {
-		fmt.Fprintf(os.Stderr, "invalid log level %s: %v, using info\n", level, err)
-		programLevel = slog.LevelInfo
-	}
-
-	leveler := &slog.LevelVar{}
-	leveler.Set(programLevel)
-
-	h := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
-		AddSource: true,
-		Level:     leveler,
-	})
-	slog.SetDefault(slog.New(h))
-}
-
 func GetRequestLogger(base *slog.Logger, r *http.Request) *slog.Logger {
 	host := r.Host
 	if host == "" {
@@ -44,27 +23,3 @@ func GetRequestLogger(base *slog.Logger, r *http.Request) *slog.Logger {
 		"x-real-ip", r.Header.Get("X-Real-Ip"),
 	)
 }
-
-// ErrorLogFilter is used to suppress "context canceled" logs from the http server when a request is canceled (e.g., when a client disconnects).
-type ErrorLogFilter struct {
-	Unwrap *log.Logger
-}
-
-func (elf *ErrorLogFilter) Write(p []byte) (n int, err error) {
-	logMessage := string(p)
-	if strings.Contains(logMessage, "context canceled") {
-		return len(p), nil // Suppress the log by doing nothing
-	}
-	if strings.Contains(logMessage, "Unsolicited response received on idle HTTP channel") {
-		return len(p), nil
-	}
-	if elf.Unwrap != nil {
-		return elf.Unwrap.Writer().Write(p)
-	}
-	return len(p), nil
-}
-
-func GetFilteredHTTPLogger() *log.Logger {
-	stdErrLogger := log.New(os.Stderr, "", log.LstdFlags) // essentially what the default logger is.
-	return log.New(&ErrorLogFilter{Unwrap: stdErrLogger}, "", 0)
-}

internal/log_test.go

@@ -1,82 +0,0 @@
-package internal
-
-import (
-	"bytes"
-	"log"
-	"log/slog"
-	"net/http"
-	"strings"
-	"testing"
-)
-
-func TestErrorLogFilter(t *testing.T) {
-	var buf bytes.Buffer
-	destLogger := log.New(&buf, "", 0)
-	errorFilterWriter := &ErrorLogFilter{Unwrap: destLogger}
-	testErrorLogger := log.New(errorFilterWriter, "", 0)
-
-	// Test Case 1: Suppressed message
-	suppressedMessage := "http: proxy error: context canceled"
-	testErrorLogger.Println(suppressedMessage)
-
-	if buf.Len() != 0 {
-		t.Errorf("Suppressed message was written to output. Output: %q", buf.String())
-	}
-	buf.Reset()
-
-	// Test Case 2: Allowed message
-	allowedMessage := "http: another error occurred"
-	testErrorLogger.Println(allowedMessage)
-
-	output := buf.String()
-	if !strings.Contains(output, allowedMessage) {
-		t.Errorf("Allowed message was not written to output. Output: %q", output)
-	}
-	if !strings.HasSuffix(output, "\n") {
-		t.Errorf("Allowed message output is missing newline. Output: %q", output)
-	}
-	buf.Reset()
-
-	// Test Case 3: Partially matching message (should be suppressed)
-	partiallyMatchingMessage := "Some other log before http: proxy error: context canceled and after"
-	testErrorLogger.Println(partiallyMatchingMessage)
-
-	if buf.Len() != 0 {
-		t.Errorf("Partially matching message was written to output. Output: %q", buf.String())
-	}
-	buf.Reset()
-}
-
-func TestGetRequestLogger(t *testing.T) {
-	// Test case 1: Normal request with Host header
-	req1, _ := http.NewRequest("GET", "http://example.com/test", nil)
-	req1.Host = "example.com"
-
-	logger := slog.Default()
-	reqLogger := GetRequestLogger(logger, req1)
-
-	// We can't easily test the actual log output without setting up a test handler,
-	// but we can verify the function doesn't panic and returns a logger
-	if reqLogger == nil {
-		t.Error("GetRequestLogger returned nil")
-	}
-
-	// Test case 2: Subrequest auth mode with X-Forwarded-Host
-	req2, _ := http.NewRequest("GET", "http://test.com/auth", nil)
-	req2.Host = ""
-	req2.Header.Set("X-Forwarded-Host", "original-site.com")
-
-	reqLogger2 := GetRequestLogger(logger, req2)
-	if reqLogger2 == nil {
-		t.Error("GetRequestLogger returned nil for X-Forwarded-Host case")
-	}
-
-	// Test case 3: No host information available
-	req3, _ := http.NewRequest("GET", "http://test.com/nohost", nil)
-	req3.Host = ""
-
-	reqLogger3 := GetRequestLogger(logger, req3)
-	if reqLogger3 == nil {
-		t.Error("GetRequestLogger returned nil for no host case")
-	}
-}