hst/instance: store priv side pid

This can receive signals, so is more useful to the caller.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/hakurei/print.go

@@ -66,7 +66,7 @@ func printShowInstance(
 
 	if instance != nil {
 		t.Printf("State\n")
-		t.Printf(" Instance:\t%s (%d)\n", instance.ID.String(), instance.PID)
+		t.Printf(" Instance:\t%s (%d -> %d)\n", instance.ID.String(), instance.PID, instance.ShimPID)
 		t.Printf(" Uptime:\t%s\n", now.Sub(instance.Time).Round(time.Second).String())
 		t.Printf("\n")
 	}

cmd/hakurei/print_test.go

@@ -18,7 +18,8 @@ var (
 	}
 	testState = &hst.State{
 		ID:      testID,
-		PID:    0xDEADBEEF,
+		PID:     0xcafebabe,
+		ShimPID: 0xdeadbeef,
 		Config:  hst.Template(),
 		Time:    testAppTime,
 	}
@@ -131,7 +132,7 @@ Session bus
 `, false},
 
 		{"instance", testState, hst.Template(), false, false, `State
- Instance:    8e2c76b066dabe574cf073bdb46eb5c1 (3735928559)
+ Instance:    8e2c76b066dabe574cf073bdb46eb5c1 (3405691582 -> 3735928559)
  Uptime:      1h2m32s
 
 App
@@ -173,7 +174,7 @@ System bus
 		{"instance pd", testState, new(hst.Config), false, false, `Error: configuration missing container state!
 
 State
- Instance:    8e2c76b066dabe574cf073bdb46eb5c1 (3735928559)
+ Instance:    8e2c76b066dabe574cf073bdb46eb5c1 (3405691582 -> 3735928559)
  Uptime:      1h2m32s
 
 App
@@ -186,7 +187,8 @@ App
 `, true},
 		{"json instance", testState, nil, false, true, `{
   "instance": "8e2c76b066dabe574cf073bdb46eb5c1",
-  "pid": 3735928559,
+  "pid": 3405691582,
+  "shim_pid": 3735928559,
   "config": {
     "id": "org.chromium.Chromium",
     "enablements": {
@@ -527,13 +529,14 @@ func TestPrintPs(t *testing.T) {
 `},
 
 		{"valid", map[hst.ID]*hst.State{testID: testState}, false, false, `    Instance    PID           Application                  Uptime
-    8e2c76b0    3735928559    9 (org.chromium.Chromium)    1h2m32s
+    8e2c76b0    3405691582    9 (org.chromium.Chromium)    1h2m32s
 `},
 		{"valid short", map[hst.ID]*hst.State{testID: testState}, true, false, "8e2c76b0\n"},
 		{"valid json", map[hst.ID]*hst.State{testID: testState}, false, true, `{
   "8e2c76b066dabe574cf073bdb46eb5c1": {
     "instance": "8e2c76b066dabe574cf073bdb46eb5c1",
-    "pid": 3735928559,
+    "pid": 3405691582,
+    "shim_pid": 3735928559,
     "config": {
       "id": "org.chromium.Chromium",
       "enablements": {

hst/instance.go

@@ -74,8 +74,11 @@ func (a *ID) UnmarshalText(text []byte) error {
 type State struct {
 	// Unique instance id, created by [NewInstanceID].
 	ID ID `json:"instance"`
-	// Shim process pid. Runs as the target user.
+	// Monitoring process pid. Runs as the priv user.
 	PID int `json:"pid"`
+	// Shim process pid. Runs as the target user.
+	ShimPID int `json:"shim_pid"`
+
 	// Configuration used to start the container.
 	Config *Config `json:"config"`
 

internal/app/process.go

@@ -291,7 +291,8 @@ func (k *outcome) main(msg message.Msg) {
 	if ok, err := ms.store.Do(k.state.identity.unwrap(), func(c state.Cursor) {
 		if err := c.Save(&hst.State{
 			ID:      k.state.id.unwrap(),
-			PID:    ms.cmd.Process.Pid,
+			PID:     os.Getpid(),
+			ShimPID: ms.cmd.Process.Pid,
 			Config:  k.config,
 			Time:    *ms.Time,
 		}); err != nil {