Add 'runsc debug' command

It prints sandbox stacks to the log to help debug stuckness. I expect
that many more options will be added in the future.

PiperOrigin-RevId: 201405931
Change-Id: I87e560800cd5a5a7b210dc25a5661363c8c3a16e

1 files changed, 29 insertions, 0 deletions

diff --git a/runsc/boot/debug.go b/runsc/boot/debug.go
new file mode 100644
index 000000000..971962c91
--- /dev/null
+++ b/runsc/boot/debug.go
@@ -0,0 +1,29 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package boot
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/log"
+)
+
+type debug struct {
+}
+
+// Stacks collects all sandbox stacks and copies them to 'stacks'.
+func (*debug) Stacks(_ *struct{}, stacks *string) error {
+	buf := log.Stacks(true)
+	*stacks = string(buf)
+	return nil
+}