Push signal-delivery and wait into the sandbox.

This is another step towards multi-container support.

Previously, we delivered signals directly to the sandbox process (which then
forwarded the signal to PID 1 inside the sandbox). Similarly, we waited on a
container by waiting on the sandbox process itself. This approach will not work
when there are multiple containers inside the sandbox, and we need to
signal/wait on individual containers.

This CL adds two new messages, ContainerSignal and ContainerWait. These
messages include the id of the container to signal/wait. The controller inside
the sandbox receives these messages and signals/waits on the appropriate
process inside the sandbox.

The container id is plumbed into the sandbox, but it currently is not used. We
still end up signaling/waiting on PID 1 in all cases.  Once we actually have
multiple containers inside the sandbox, we will need to keep some sort of map
of container id -> pid (or possibly pid namespace), and signal/kill the
appropriate process for the container.

PiperOrigin-RevId: 197028366
Change-Id: I07b4d5dc91ecd2affc1447e6b4bdd6b0b7360895

1 files changed, 4 insertions, 3 deletions

diff --git a/runsc/boot/events.go b/runsc/boot/events.go
index ef6459b01..0eb75c14c 100644
--- a/runsc/boot/events.go
+++ b/runsc/boot/events.go
@@ -59,10 +59,11 @@ type Memory struct {
 	Raw       map[string]uint64 `json:"raw,omitempty"`
 }
 
-func (a *application) Event(_ *struct{}, out *Event) error {
+// Event gets the events from the container.
+func (cm *containerManager) Event(_ *struct{}, out *Event) error {
 	stats := &Stats{}
-	stats.populateMemory(a.k)
-	stats.populatePIDs(a.k)
+	stats.populateMemory(cm.k)
+	stats.populatePIDs(cm.k)
 	*out = Event{Type: "stats", Data: stats}
 	return nil
 }