log: capture exit conditions

Replace executions of 'os.Exit()', 'log.Fatal()', and 'log.Fatalf()' with
'TraceLogger.Exit()', 'TraceLogger.Fatal()', and 'TraceLogger.Fatalf()',
respectively. When these are called, log the appropriate 'exit'/'atexit'
events.

Note that 'TraceLogger.Fatal()' and 'TraceLogger.Fatalf()' currently do not
log the error (or error format + args) they receive. This will be updated in
a later patch, but the unused arguments are added now to avoid needing to
remove then later add back the arguments passed to 'log.Fatal()' and
'log.Fatalf()' by their callers.

Signed-off-by: Victoria Dye <[email protected]>

Author: vdye

cmd/git-bundle-server/main.go

@@ -2,14 +2,13 @@ package main
 
 import (
 	"context"
-	"log"
 	"os"
 
 	"github.com/github/git-bundle-server/internal/argparse"
-	tracelog "github.com/github/git-bundle-server/internal/log"
+	"github.com/github/git-bundle-server/internal/log"
 )
 
-func all(logger tracelog.TraceLogger) []argparse.Subcommand {
+func all(logger log.TraceLogger) []argparse.Subcommand {
 	return []argparse.Subcommand{
 		NewDeleteCommand(logger),
 		NewInitCommand(logger),
@@ -22,7 +21,7 @@ func all(logger tracelog.TraceLogger) []argparse.Subcommand {
 }
 
 func main() {
-	tracelog.WithTraceLogger(context.Background(), func(ctx context.Context, logger tracelog.TraceLogger) {
+	log.WithTraceLogger(context.Background(), func(ctx context.Context, logger log.TraceLogger) {
 		cmds := all(logger)
 
 		parser := argparse.NewArgParser(logger, "git-bundle-server <command> [<options>]")
@@ -34,7 +33,7 @@ func main() {
 
 		err := parser.InvokeSubcommand(ctx)
 		if err != nil {
-			log.Fatalf("Failed with error: %s", err)
+			logger.Fatalf(ctx, "Failed with error: %s", err)
 		}
 	})
 }

cmd/git-bundle-web-server/bundle-server.go

@@ -3,7 +3,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"log"
 	"net/http"
 	"os"
 	"os/signal"
@@ -13,17 +12,17 @@ import (
 
 	"github.com/github/git-bundle-server/internal/common"
 	"github.com/github/git-bundle-server/internal/core"
-	tracelog "github.com/github/git-bundle-server/internal/log"
+	"github.com/github/git-bundle-server/internal/log"
 )
 
 type bundleWebServer struct {
-	logger             tracelog.TraceLogger
+	logger             log.TraceLogger
 	server             *http.Server
 	serverWaitGroup    *sync.WaitGroup
 	listenAndServeFunc func() error
 }
 
-func NewBundleWebServer(logger tracelog.TraceLogger,
+func NewBundleWebServer(logger log.TraceLogger,
 	port string, certFile string, keyFile string,
 ) *bundleWebServer {
 	bundleServer := &bundleWebServer{
@@ -123,7 +122,7 @@ func (b *bundleWebServer) StartServerAsync(ctx context.Context) {
 		// Return error unless it indicates graceful shutdown
 		err := b.listenAndServeFunc()
 		if err != nil && err != http.ErrServerClosed {
-			log.Fatal(err)
+			b.logger.Fatal(ctx, err)
 		}
 	}(ctx)
 

internal/argparse/argparse.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"os"
 	"strings"
 
 	"github.com/github/git-bundle-server/internal/log"
@@ -146,7 +145,7 @@ func (a *argParser) Parse(ctx context.Context, args []string) {
 	if err != nil {
 		// The error was already printed (via a.FlagSet.Usage()), so we
 		// just need to exit
-		os.Exit(usageExitCode)
+		a.logger.Exit(ctx, usageExitCode)
 	}
 
 	if len(a.subcommands) > 0 {
@@ -222,5 +221,5 @@ func (a *argParser) Usage(ctx context.Context, errFmt string, args ...any) {
 	fmt.Fprintf(a.FlagSet.Output(), errFmt+"\n", args...)
 	a.FlagSet.Usage()
 
-	os.Exit(usageExitCode)
+	a.logger.Exit(ctx, usageExitCode)
 }

internal/log/logger.go

@@ -2,10 +2,13 @@ package log
 
 import (
 	"context"
-	"os"
 )
 
-type TraceLogger interface{}
+type TraceLogger interface {
+	Exit(ctx context.Context, exitCode int)
+	Fatal(ctx context.Context, err error)
+	Fatalf(ctx context.Context, format string, a ...any)
+}
 
 type traceLoggerInternal interface {
 	// Internal setup/teardown functions
@@ -26,8 +29,7 @@ func WithTraceLogger(
 	defer func() {
 		if recover() != nil {
 			// Panicking - exit with error
-			logger.logExit(ctx, 1)
-			os.Exit(1)
+			logger.Exit(ctx, 1)
 		} else {
 			// Just log the exit (but don't os.Exit()) so we can exit normally
 			logger.logExit(ctx, 0)

internal/log/trace2.go

@@ -165,3 +165,16 @@ func (t *Trace2) logExit(ctx context.Context, exitCode int) {
 
 	t.logger.Sync()
 }
+
+func (t *Trace2) Exit(ctx context.Context, exitCode int) {
+	t.logExit(ctx, exitCode)
+	os.Exit(exitCode)
+}
+
+func (t *Trace2) Fatal(ctx context.Context, err error) {
+	t.Exit(ctx, 1)
+}
+
+func (t *Trace2) Fatalf(ctx context.Context, format string, a ...any) {
+	t.Exit(ctx, 1)
+}