fix: output logs to file during loading

agent/agent.go

@@ -78,6 +78,7 @@ func SetupAgent(options ac.AgentOptions) {
 		{
 			bf, err := loader.LoadBPF(&options)
 			if err != nil {
+				common.AgentLog.Error("Failed to load BPF programs: ", err)
 				if bf != nil {
 					bf.Close()
 				}

agent/render/loader/loader_render.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"kyanos/agent/common"
+	c "kyanos/common"
 	"os"
 	"strings"
 	"time"
@@ -108,6 +109,7 @@ func (m model) View() string {
 }
 
 func Start(ctx context.Context, options common.AgentOptions) {
+	c.SetLogToFile()
 	const numLastResults = 5
 	m := model{
 		spinner: spinner.New(spinner.WithSpinner(spinner.Dot)),

bpf/loader/btf.go

@@ -63,9 +63,9 @@ func generateBTF(fileBytes []byte) (*btf.Spec, error) {
 	return btfPath, nil
 }
 
-func loadBTFSpec(options *ac.AgentOptions) *btf.Spec {
+func loadBTFSpec(options *ac.AgentOptions) (*btf.Spec, error) {
 	if bpf.IsKernelSupportHasBTF() {
-		return nil
+		return nil, nil
 	}
 
 	options.LoadPorgressChannel <- "starting load BTF file"
@@ -73,7 +73,8 @@ func loadBTFSpec(options *ac.AgentOptions) *btf.Spec {
 	if options.BTFFilePath != "" {
 		btfPath, err := btf.LoadSpec(options.BTFFilePath)
 		if err != nil {
-			common.AgentLog.Fatalf("can't load btf spec from file %s: %v", options.BTFFilePath, err)
+			common.AgentLog.Warnf("can't load btf spec from file %s: %v\n", options.BTFFilePath, err)
+			return nil, err
 		}
 		spec = btfPath
 		options.LoadPorgressChannel <- "starting load BTF file: success!"
@@ -84,11 +85,11 @@ func loadBTFSpec(options *ac.AgentOptions) *btf.Spec {
 			if needGenerateBTF {
 				spec, err = generateBTF(fileBytes)
 				if err != nil {
-					common.AgentLog.Warnf("failed to generate btf file: %+v", err)
+					common.AgentLog.Warnf("failed to generate btf file: %+v\n", err)
 				}
 			}
 		} else {
-			common.AgentLog.Warnf("failed to load embeded btf file: %+v", err)
+			common.AgentLog.Warnf("failed to load embeded btf file: %+v\n", err)
 		}
 	}
 
@@ -97,7 +98,7 @@ func loadBTFSpec(options *ac.AgentOptions) *btf.Spec {
 		options.LoadPorgressChannel <- "starting load BTF from network..."
 		btfSpec, _, err := loadBTFSpecFallback("")
 		if err != nil {
-			common.AgentLog.Warnf("failed to get btf file from network: %+v", err)
+			common.AgentLog.Warnf("failed to get btf file from network: %+v\n", err)
 		} else {
 			spec = btfSpec
 		}
@@ -110,18 +111,18 @@ func loadBTFSpec(options *ac.AgentOptions) *btf.Spec {
 			if needGenerateBTF {
 				spec, err = generateBTF(fileBytes)
 				if err != nil {
-					common.AgentLog.Warnf("failed to generate btf file (best matched): %+v", err)
+					common.AgentLog.Warnf("failed to generate btf file (best matched): %+v\n", err)
 				}
 			}
 		} else {
-			common.AgentLog.Warnf("failed to load embedded btf file (best matched): %+v", err)
+			common.AgentLog.Warnf("failed to load embedded btf file (best matched): %+v\n", err)
 		}
 	}
 
 	if spec == nil {
-		common.AgentLog.Fatalf("can't find btf file to load!")
+		return nil, fmt.Errorf("can't find btf file to load!")
 	}
-	return spec
+	return spec, nil
 }
 
 func loadBTFSpecFallback(path string) (*btf.Spec, string, error) {

bpf/loader/loader.go

@@ -57,12 +57,17 @@ func LoadBPF(options *ac.AgentOptions) (*BPF, error) {
 	var bf *BPF = &BPF{}
 
 	if err := features.HaveProgramType(ebpf.Kprobe); errors.Is(err, ebpf.ErrNotSupported) {
-		common.AgentLog.Fatalf("Require oldest kernel version is 3.10.0-957, pls check your kernel version by `uname -r`")
+		common.AgentLog.Errorf("Require oldest kernel version is 3.10.0-957, pls check your kernel version by `uname -r`\n")
+		return nil, err
 	}
 
+	btfSpec, err := loadBTFSpec(options)
+	if err != nil {
+		return nil, err
+	}
 	collectionOptions = &ebpf.CollectionOptions{
 		Programs: ebpf.ProgramOptions{
-			KernelTypes: loadBTFSpec(options),
+			KernelTypes: btfSpec,
 		},
 	}
 

common/log.go

@@ -36,8 +36,13 @@ var ConntrackLog *Klogger = &Klogger{logrus.New()}
 var ProtocolParserLog *Klogger = &Klogger{logrus.New()}
 
 var Loggers []*Klogger = []*Klogger{DefaultLog, AgentLog, BPFLog, BPFEventLog, UprobeLog, ConntrackLog, ProtocolParserLog}
+var SetLogToFileFlag = false
 
 func SetLogToFile() {
+	if SetLogToFileFlag {
+		return
+	}
+	SetLogToFileFlag = true
 	for _, l := range Loggers {
 		l.SetOut(io.Discard)
 		logdir := "/tmp"

go.sum

@@ -317,8 +317,6 @@ golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.27.0 h1:GXm2NjJrPaiv/h1tb2UH8QfgC/hOf/+z0p6PT8o1w7A=
 golang.org/x/crypto v0.27.0/go.mod h1:1Xngt8kV6Dvbssa53Ziq6Eqn0HqbZi5Z6R0ZpwQzt70=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
-golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f h1:XdNn9LlyWAhLVp6P/i8QYBW+hlyhrhei9uErw2B5GJo=
-golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f/go.mod h1:D5SMRVC3C2/4+F/DB1wZsLRnSNimn2Sp/NPsCrsv8ak=
 golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d h1:0olWaB5pg3+oychR51GUVCEsGkeCU/2JxjBgIo4f3M0=
 golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -343,8 +341,6 @@ golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.9.0 h1:fEo0HyrW1GIgZdpbhCRO0PkJajUS5H9IFUztCgEo2jQ=
-golang.org/x/sync v0.9.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
 golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=