From 802217158c50a13f9b29249a71522c1f8cea5385 Mon Sep 17 00:00:00 2001
From: "T. von Dein" <scip@noreply.codeberg.org>
Date: Thu, 18 Jun 2026 08:54:00 +0200
Subject: [PATCH] feature/add-profiler (#42)

---
 .gitignore        |  2 ++
 Makefile          |  7 +++++--
 cmd/root.go       | 28 ++++++++++++++++++++++++++++
 pkg/cfg/config.go |  3 ++-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index 77d8a3e..e056ce6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,3 +30,5 @@ esctl
 *.sh
 *.json
 *.log
+
+cpu.profile
diff --git a/Makefile b/Makefile
index c141875..8a6c325 100644
--- a/Makefile
+++ b/Makefile
@@ -106,5 +106,8 @@ show-versions: buildlocal
 	@echo "### go version used for building:"
 	@grep -m 1 go go.mod
 
-# lint:
-# 	golangci-lint run -p bugs -p unused
+.PHONY: profile
+profile: buildlocal
+	./esctl api ls --profile-file cpu.profile
+	go tool pprof -text esctl cpu.profile
+	go tool pprof --http localhost:8888 ./esctl cpu.profile
diff --git a/cmd/root.go b/cmd/root.go
index 84d4804..f939257 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -19,7 +19,9 @@ package cmd
 import (
 	"context"
 	"fmt"
+	golog "log"
 	"os"
+	"runtime/pprof"
 
 	"codeberg.org/scip/esctl/pkg/cfg"
 	"codeberg.org/scip/esctl/pkg/es"
@@ -83,6 +85,12 @@ func Main() int {
 				Usage:       "output mode (tsv, markdown, json, yaml) default: tsv",
 				Destination: &conf.Output,
 			},
+			&cli.StringFlag{
+				Name:        "profile-file",
+				Usage:       "golang profiler output file",
+				Destination: &conf.ProfileFile,
+				Hidden:      true,
+			},
 		},
 
 		Commands: []*cli.Command{
@@ -115,6 +123,26 @@ func Main() int {
 
 			log.Init(conf)
 
+			if conf.ProfileFile != "" {
+				// enable  cpu profiling. Do  NOT use q  to stop the  game but
+				// close the window to get a profile
+				fd, err := os.Create(conf.ProfileFile)
+				if err != nil {
+					return nil, err
+				}
+				defer func() {
+					if err := fd.Close(); err != nil {
+						golog.Fatal(err)
+					}
+				}()
+
+				if err := pprof.StartCPUProfile(fd); err != nil {
+					golog.Fatal(err)
+				}
+
+				defer pprof.StopCPUProfile()
+			}
+
 			return nil, nil
 		},
 	}
diff --git a/pkg/cfg/config.go b/pkg/cfg/config.go
index 26b0f8c..5994f7a 100644
--- a/pkg/cfg/config.go
+++ b/pkg/cfg/config.go
@@ -54,7 +54,8 @@ type Config struct {
 	Output         string // -o <mode>
 	Clusters       map[string]*Cluster
 	DefaultCluster *Cluster
-	HaveJQ         bool // determined at runtime by ourselfes
+	HaveJQ         bool   // determined at runtime by ourselfes
+	ProfileFile    string // for internal use (golang profiling)
 
 	Index            string // index: -i
 	Failed, Partials bool   // index: flags