Add flags to filter errors and status codes (#95)

http-tracer.go

@@ -22,6 +22,7 @@ import (
 	"io"
 	"io/ioutil"
 	"net/http"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -301,6 +302,16 @@ func doTrace(trace TraceInfo, backend *Backend) {
 		return
 	}
 
+	if globalErrorsOnly && (st.StatusCode < 400 || st.StatusCode >= 600) {
+		return
+	}
+
+	if len(globalStatusCodes) > 0 {
+		if !slices.Contains(globalStatusCodes, st.StatusCode) {
+			return
+		}
+	}
+
 	if globalJSONEnabled {
 		if globalDebugEnabled {
 			buf := &bytes.Buffer{}

main.go

@@ -66,6 +66,8 @@ var (
 	globalTrace          string
 	globalJSONEnabled    bool
 	globalConsoleDisplay bool
+	globalErrorsOnly     bool
+	globalStatusCodes    []int
 	globalConnStats      []*ConnStats
 	log2                 *logrus.Logger
 )
@@ -807,6 +809,8 @@ func sidekickMain(ctx *cli.Context) {
 	globalQuietEnabled = ctx.GlobalBool("quiet")
 	globalConsoleDisplay = globalLoggingEnabled || ctx.IsSet("trace") || !term.IsTerminal(int(os.Stdout.Fd()))
 	globalDebugEnabled = ctx.GlobalBool("debug")
+	globalErrorsOnly = ctx.GlobalBool("errors")
+	globalStatusCodes = ctx.GlobalIntSlice("status-code")
 
 	go func() {
 		t := time.NewTicker(ctx.GlobalDuration("dns-ttl"))
@@ -961,6 +965,14 @@ func main() {
 			Usage: "choose custom DNS TTL value for DNS refreshes for load balanced endpoints",
 			Value: 10 * time.Minute,
 		},
+		cli.BoolFlag{
+			Name:  "errors , e",
+			Usage: "filter out any non-error responses",
+		},
+		cli.IntSliceFlag{
+			Name:  "status-code",
+			Usage: "filter by given status code",
+		},
 	}
 	app.CustomAppHelpTemplate = `NAME:
   {{.Name}} - {{.Description}}