Merge release-20210726.0-32-gcbb99336c (automated)

4 files changed, 38 insertions, 0 deletions

diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index 548797788..60b532798 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -109,6 +109,11 @@ const (
 	LifecycleResume = "Lifecycle.Resume"
 )
 
+// Filesystem related commands (see fs.go for more details).
+const (
+	FsCat = "Fs.Cat"
+)
+
 // ControlSocketAddr generates an abstract unix socket name for the given ID.
 func ControlSocketAddr(id string) string {
 	return fmt.Sprintf("\x00runsc-sandbox.%s", id)
@@ -151,6 +156,7 @@ func newController(fd int, l *Loader) (*controller, error) {
 	ctrl.srv.Register(&debug{})
 	ctrl.srv.Register(&control.Logging{})
 	ctrl.srv.Register(&control.Lifecycle{l.k})
+	ctrl.srv.Register(&control.Fs{l.k})
 
 	if l.root.conf.ProfileEnable {
 		ctrl.srv.Register(control.NewProfile(l.k))
diff --git a/runsc/cmd/debug.go b/runsc/cmd/debug.go
index da81cf048..f773ccca0 100644
--- a/runsc/cmd/debug.go
+++ b/runsc/cmd/debug.go
@@ -48,6 +48,7 @@ type Debug struct {
 	delay        time.Duration
 	duration     time.Duration
 	ps           bool
+	cat          stringSlice
 }
 
 // Name implements subcommands.Command.
@@ -81,6 +82,7 @@ func (d *Debug) SetFlags(f *flag.FlagSet) {
 	f.StringVar(&d.logLevel, "log-level", "", "The log level to set: warning (0), info (1), or debug (2).")
 	f.StringVar(&d.logPackets, "log-packets", "", "A boolean value to enable or disable packet logging: true or false.")
 	f.BoolVar(&d.ps, "ps", false, "lists processes")
+	f.Var(&d.cat, "cat", "reads files and print to standard output")
 }
 
 // Execute implements subcommands.Command.Execute.
@@ -367,5 +369,11 @@ func (d *Debug) Execute(_ context.Context, f *flag.FlagSet, args ...interface{})
 		return subcommands.ExitFailure
 	}
 
+	if d.cat != nil {
+		if err := c.Cat(d.cat, os.Stdout); err != nil {
+			return Errorf("Cat failed: %v", err)
+		}
+	}
+
 	return subcommands.ExitSuccess
 }
diff --git a/runsc/container/container.go b/runsc/container/container.go
index 6a9a07afe..d1f979eb2 100644
--- a/runsc/container/container.go
+++ b/runsc/container/container.go
@@ -646,6 +646,12 @@ func (c *Container) Resume() error {
 	return c.saveLocked()
 }
 
+// Cat prints out the content of the files.
+func (c *Container) Cat(files []string, out *os.File) error {
+	log.Debugf("Cat in container, cid: %s, files: %+v", c.ID, files)
+	return c.Sandbox.Cat(c.ID, files, out)
+}
+
 // State returns the metadata of the container.
 func (c *Container) State() specs.State {
 	return specs.State{
diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go
index 822da8c5e..b15572a98 100644
--- a/runsc/sandbox/sandbox.go
+++ b/runsc/sandbox/sandbox.go
@@ -1002,6 +1002,24 @@ func (s *Sandbox) Resume(cid string) error {
 	return nil
 }
 
+// Cat sends the cat call for a container in the sandbox.
+func (s *Sandbox) Cat(cid string, files []string, out *os.File) error {
+	log.Debugf("Cat sandbox %q", s.ID)
+	conn, err := s.sandboxConnect()
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	if err := conn.Call(boot.FsCat, &control.CatOpts{
+		Files:       files,
+		FilePayload: urpc.FilePayload{Files: []*os.File{out}},
+	}, nil); err != nil {
+		return fmt.Errorf("Cat container %q: %v", cid, err)
+	}
+	return nil
+}
+
 // IsRunning returns true if the sandbox or gofer process is running.
 func (s *Sandbox) IsRunning() bool {
 	if s.Pid != 0 {