Read FDB client traces when --debug is passed on the start.

Author: melgenek

demo/tls/docker-compose.yaml

@@ -32,13 +32,11 @@ services:
   f8n-demo:
     container_name: f8n-demo
     image: ghcr.io/melgenek/f8n:v0.3.0
-    environment:
-      FDB_NETWORK_OPTION_TRACE_ENABLE: "/tmp"
-      FDB_NETWORK_OPTION_TRACE_FORMAT: "json"
     volumes:
       - ./fdb_pki:/opt/fdb/tls:ro
       - ./etcd_pki:/opt/etcd/tls:ro
     command:
+      - --debug
       - --endpoint
       - "fdb://docker:docker@fdb-demo:4500:tls"
       # FDB client TLS

pkg/drivers/fdb/fdb.go

@@ -65,6 +65,9 @@ func (f *FDB) Start(ctx context.Context) error {
 	fdb.MustAPIVersion(730)
 	f.ctx = ctx
 
+	if err := logFDBTraces(); err != nil {
+		return err
+	}
 	if err := f.setTLSConfig(); err != nil {
 		return err
 	}

pkg/drivers/fdb/fdb_log_util.go

@@ -0,0 +1,70 @@
+package fdb
+
+import (
+	"bufio"
+	"fmt"
+	"github.com/apple/foundationdb/bindings/go/src/fdb"
+	"github.com/sirupsen/logrus"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+func newestTrace() (string, error) {
+	files, _ := filepath.Glob("/tmp/trace*.json")
+	if len(files) == 0 {
+		return "", fmt.Errorf("no files found")
+	}
+	sort.Slice(files, func(i, j int) bool {
+		fi, _ := os.Stat(files[i])
+		fj, _ := os.Stat(files[j])
+		return fi.ModTime().After(fj.ModTime())
+	})
+	return files[0], nil
+}
+
+func followFile(file string) {
+	f, err := os.Open(file)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	_, err = f.Seek(0, io.SeekStart)
+	if err != nil {
+		return
+	}
+	r := bufio.NewReader(f)
+
+	for {
+		line, err := r.ReadString('\n')
+		if err != nil {
+			return
+		}
+		logrus.Debug(strings.TrimRight(line, "\n"))
+	}
+}
+
+func logFDBTraces() error {
+	if logrus.IsLevelEnabled(logrus.DebugLevel) {
+		if err := fdb.Options().SetTraceEnable("/tmp"); err != nil {
+			return err
+		}
+		if err := fdb.Options().SetTraceFormat("json"); err != nil {
+			return err
+		}
+		go func() {
+			prevFile := ""
+			for {
+				nextFile, err := newestTrace()
+				if err == nil && nextFile != prevFile {
+					followFile(nextFile)
+					prevFile = nextFile
+				}
+			}
+		}()
+	}
+	return nil
+}

pkg/drivers/fdb/fdb_test.go

@@ -26,6 +26,12 @@ var connectionString = env.GetString("FDB_CONNECTION_STRING", "docker:docker@127
 func TestMain(m *testing.M) {
 	CleanDirOnStart = true
 	logrus.SetLevel(logrus.WarnLevel)
+	logrus.SetFormatter(&logrus.JSONFormatter{
+		FieldMap: logrus.FieldMap{
+			logrus.FieldKeyLevel: "severity",
+			logrus.FieldKeyMsg:   "message",
+		},
+	})
 	forceRetryTransaction = func(i int) bool { return i < 2 }
 
 	code := m.Run()