[ws-daemon] Collect logs from runc command

components/ws-daemon/pkg/content/initializer.go

@@ -9,11 +9,13 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
+	"sync"
 	"syscall"
 
 	"github.com/opencontainers/runtime-spec/specs-go"
@@ -229,12 +231,36 @@ func RunInitializer(ctx context.Context, destination string, initializer *csapi.
 		withDebug = "--debug"
 	}
 
+	logEntry := log.WithFields(opts.OWI)
+
+	rd, rw := io.Pipe()
+	defer rw.Close()
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		b := make([]byte, 4096)
+		for {
+			n, err := rd.Read(b)
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				log.WithError(err).Error("cannot read from content initializer output")
+				return
+			}
+
+			logEntry.Debug(string(b[:n]))
+		}
+	}()
+
 	cmd = exec.Command("runc", "--root", "state", withDebug, "--log-format", "json", "run", "gogogo")
 	cmd.Dir = tmpdir
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
+	cmd.Stdout = rw
+	cmd.Stderr = rw
 	cmd.Stdin = os.Stdin
 	err = cmd.Run()
+	wg.Wait()
 	if err != nil {
 		if exiterr, ok := err.(*exec.ExitError); ok {
 			// The program has exited with an exit code != 0. If it's 42, it was deliberate.
@@ -249,6 +275,8 @@ func RunInitializer(ctx context.Context, destination string, initializer *csapi.
 	return nil
 }
 
+// CombinedOutput
+
 // RunInitializerChild is the function that's expected to run when we call `/proc/self/exe content-initializer`
 func RunInitializerChild() (err error) {
 	fc, err := os.ReadFile("/content.json")