Updated cleanup code to be more explicit about ignoring errors.

Errors are shown as being ignored by assigning to the blank identifier.

PiperOrigin-RevId: 218103819
Change-Id: I7cc7b9d8ac503a03de5504ebdeb99ed30a531cf2

runsc/cgroup/cgroup.go

@@ -190,7 +190,9 @@ func (c *Cgroup) Install(res *specs.LinuxResources) error {
 	// Mark that cgroup resources are owned by me.
 	log.Debugf("Creating cgroup %q", c.Name)
 	c.Own = true
-	clean := specutils.MakeCleanup(func() { c.Uninstall() })
+	// The Cleanup object cleans up partially created cgroups when an error occurs.
+	// Errors occuring during cleanup itself are ignored.
+	clean := specutils.MakeCleanup(func() { _ = c.Uninstall() })
 	defer clean.Clean()
 
 	for key, ctrl := range controllers {

runsc/container/container.go

@@ -262,7 +262,9 @@ func Create(id string, spec *specs.Spec, conf *boot.Config, bundleDir, consoleSo
 		Status:        Creating,
 		Owner:         os.Getenv("USER"),
 	}
-	cu := specutils.MakeCleanup(func() { c.Destroy() })
+	// The Cleanup object cleans up partially created containers when an error occurs.
+	// Any errors occuring during cleanup itself are ignored.
+	cu := specutils.MakeCleanup(func() { _ = c.Destroy() })
 	defer cu.Clean()
 
 	// If the metadata annotations indicate that this container should be
@@ -424,6 +426,8 @@ func Run(id string, spec *specs.Spec, conf *boot.Config, bundleDir, consoleSocke
 	if err != nil {
 		return 0, fmt.Errorf("error creating container: %v", err)
 	}
+	// Clean up partially created container if an error ocurrs.
+	// Any errors returned by Destroy() itself are ignored.
 	defer c.Destroy()
 
 	if err := c.Start(conf); err != nil {

runsc/sandbox/sandbox.go

@@ -68,7 +68,9 @@ type Sandbox struct {
 // sandbox.
 func Create(id string, spec *specs.Spec, conf *boot.Config, bundleDir, consoleSocket, userLog string, ioFiles []*os.File) (*Sandbox, error) {
 	s := &Sandbox{ID: id}
-	c := specutils.MakeCleanup(func() { s.destroy() })
+	// The Cleanup object cleans up partially created sandboxes when an error occurs.
+	// Any errors occuring during cleanup itself are ignored.
+	c := specutils.MakeCleanup(func() { _ = s.destroy() })
 	defer c.Clean()
 
 	if cg, ok := cgroup.New(spec); ok {