agent: use hypervisor pid as backup proxy pid for non-kata proxy cases

Then we can check hypervisor liveness in those cases to avoid long
timeout when connecting to the agent when hypervisor is dead.

For kata-agent, we still use the kata-proxy pid for the same purpose.

Signed-off-by: Peng Tao <bergwolf@hyper.sh>

virtcontainers/kata_agent.go

@@ -616,6 +616,7 @@ func (k *kataAgent) startProxy(sandbox *Sandbox) error {
 
 	proxyParams := proxyParams{
 		id:         sandbox.id,
+		hid:        sandbox.hypervisor.pid(),
 		path:       sandbox.config.ProxyConfig.Path,
 		agentURL:   agentURL,
 		consoleURL: consoleURL,
@@ -1600,7 +1601,14 @@ func (k *kataAgent) connect() error {
 		return nil
 	}
 
-	k.Logger().WithField("url", k.state.URL).Info("New client")
+	if k.state.ProxyPid > 0 {
+		// check that proxy is running before talk with it avoiding long timeouts
+		if err := syscall.Kill(k.state.ProxyPid, syscall.Signal(0)); err != nil {
+			return errors.New("Proxy is not running")
+		}
+	}
+
+	k.Logger().WithField("url", k.state.URL).WithField("proxy", k.state.ProxyPid).Info("New client")
 	client, err := kataclient.NewAgentClient(k.ctx, k.state.URL, k.proxyBuiltIn)
 	if err != nil {
 		k.dead = true
@@ -1792,13 +1800,6 @@ func (k *kataAgent) sendReq(request interface{}) (interface{}, error) {
 	span.SetTag("request", request)
 	defer span.Finish()
 
-	if k.state.ProxyPid > 0 {
-		// check that proxy is running before talk with it avoiding long timeouts
-		if err := syscall.Kill(k.state.ProxyPid, syscall.Signal(0)); err != nil {
-			return nil, fmt.Errorf("Proxy is not running: %v", err)
-		}
-	}
-
 	if err := k.connect(); err != nil {
 		return nil, err
 	}

virtcontainers/kata_builtin_proxy.go

@@ -64,7 +64,7 @@ func (p *kataBuiltInProxy) start(params proxyParams) (int, string, error) {
 		}
 	}
 
-	return -1, params.agentURL, nil
+	return params.hid, params.agentURL, nil
 }
 
 // stop is the proxy stop implementation for kata builtin proxy.

virtcontainers/no_proxy.go

@@ -34,7 +34,7 @@ func (p *noProxy) start(params proxyParams) (int, string, error) {
 		return -1, "", fmt.Errorf("AgentURL cannot be empty")
 	}
 
-	return 0, params.agentURL, nil
+	return params.hid, params.agentURL, nil
 }
 
 // stop is noProxy stop implementation for proxy interface.

virtcontainers/noop_proxy.go

@@ -14,7 +14,7 @@ var noopProxyURL = "noopProxyURL"
 // register is the proxy start implementation for testing purpose.
 // It does nothing.
 func (p *noopProxy) start(params proxyParams) (int, string, error) {
-	return 0, noopProxyURL, nil
+	return params.hid, noopProxyURL, nil
 }
 
 // stop is the proxy stop implementation for testing purpose.

virtcontainers/proxy.go

@@ -28,6 +28,7 @@ type proxyParams struct {
 	agentURL   string
 	consoleURL string
 	logger     *logrus.Entry
+	hid        int
 	debug      bool
 }