fix SSH ping CPU spin and Linux releases

frontend/scripts/test-session-lifecycle.js

@@ -222,11 +222,82 @@ async function testCompleteAppTeardownIsImmediateAndIdempotent() {
   assert.strictEqual(app._closingSessions.size, 0);
 }
 
+async function testLatencyPingIsSingleFlightAndIgnoresStaleResults() {
+  const flushAsync = () => new Promise((resolve) => setImmediate(resolve));
+  let nextTimerID = 1;
+  const timers = new Map();
+  const latencyEl = { textContent: "", className: "" };
+  const context = loadScript("src/js/app.js", {
+    setTimeout: (callback) => {
+      const id = nextTimerID++;
+      timers.set(id, callback);
+      return id;
+    },
+    clearTimeout: (id) => timers.delete(id),
+    document: {
+      querySelector: () => null,
+      getElementById: (id) => (id === "status-latency" ? latencyEl : null),
+      addEventListener: () => {},
+    },
+  });
+  const App = context.window.NexusTerminal.App;
+  const app = Object.create(App.prototype);
+  app._latencySessionID = null;
+  app._latencyTimer = null;
+  app._latencyGeneration = 0;
+  app._latencyPingInFlight = false;
+
+  const pending = [];
+  context.window.NexusTerminal.wailsService = {
+    PingSession: (sessionID) =>
+      new Promise((resolve, reject) => {
+        pending.push({ sessionID, resolve, reject });
+      }),
+  };
+
+  app._startLatencyPing("session-a");
+  app._startLatencyPing("session-a");
+  assert.strictEqual(pending.length, 1, "an in-flight ping must not overlap");
+  assert.strictEqual(timers.size, 0, "the next ping waits for completion");
+
+  app._startLatencyPing("session-b");
+  assert.strictEqual(pending.length, 2);
+  pending[0].reject(new Error("stale session closed"));
+  await flushAsync();
+  assert.strictEqual(app._latencySessionID, "session-b");
+  assert.strictEqual(
+    app._latencyPingInFlight,
+    true,
+    "a stale rejection must not stop the current session ping",
+  );
+
+  pending[1].resolve(42);
+  await flushAsync();
+  assert.strictEqual(latencyEl.textContent, "42 ms");
+  assert.strictEqual(latencyEl.className, "latency-good");
+  assert.strictEqual(timers.size, 1, "one follow-up ping should be scheduled");
+
+  const followUp = timers.values().next().value;
+  timers.clear();
+  followUp();
+  assert.strictEqual(pending.length, 3);
+  assert.strictEqual(pending[2].sessionID, "session-b");
+  assert.strictEqual(timers.size, 0, "follow-up pings must also be single-flight");
+
+  pending[2].resolve(250);
+  await flushAsync();
+  assert.strictEqual(latencyEl.className, "latency-bad");
+  assert.strictEqual(timers.size, 1);
+  app._stopLatencyPing();
+  assert.strictEqual(timers.size, 0);
+}
+
 (async () => {
   await testRepeatedSplitCleanup();
   testClosedPaneRejectsLateConnection();
   testPerSessionStoresReleaseIDs();
   await testCompleteAppTeardownIsImmediateAndIdempotent();
+  await testLatencyPingIsSingleFlightAndIgnoresStaleResults();
   console.log("Session lifecycle regression tests passed.");
 })().catch((err) => {
   console.error(err);

frontend/src/js/app.js

@@ -49,6 +49,10 @@
       this.leviathan = new LeviathanWorkbench(this);
       /** @type {Map<string, Promise<void>>} Idempotent in-flight session closes. */
       this._closingSessions = new Map();
+      this._latencySessionID = null;
+      this._latencyTimer = null;
+      this._latencyGeneration = 0;
+      this._latencyPingInFlight = false;
       this.updateInfo = null;
       this.mode = "nexus";
     }
@@ -1362,17 +1366,44 @@
     }
 
     _startLatencyPing(sessionID) {
-      // Don't restart if already pinging the same session.
+      // Do not queue overlapping backend requests for the active session.
-      if (this._latencySessionID === sessionID && this._latencyTimer) return;
+      if (
+        this._latencySessionID === sessionID &&
+        (this._latencyTimer || this._latencyPingInFlight)
+      ) {
+        return;
+      }
       this._stopLatencyPing();
       this._latencySessionID = sessionID;
+      const generation = this._latencyGeneration;
+
+      const isCurrent = () =>
+        this._latencyGeneration === generation &&
+        this._latencySessionID === sessionID;
+
+      const scheduleNext = () => {
+        if (!isCurrent() || this._latencyTimer) return;
+        this._latencyTimer = setTimeout(() => {
+          this._latencyTimer = null;
+          void doPing();
+        }, 10000);
+      };
 
       const doPing = async () => {
-        if (!window.NexusTerminal?.wailsService) return;
+        if (!isCurrent()) return;
+        if (!window.NexusTerminal?.wailsService) {
+          scheduleNext();
+          return;
+        }
+
+        this._latencyPingInFlight = true;
+        let succeeded = false;
         try {
           const ms = await window.NexusTerminal.wailsService.PingSession(sessionID);
+          if (!isCurrent()) return;
+          succeeded = true;
           const el = document.getElementById("status-latency");
-          if (el && this._latencySessionID === sessionID) {
+          if (el) {
             el.textContent = ms + " ms";
             el.className =
               ms < 100
@@ -1382,6 +1413,7 @@
                   : "latency-bad";
           }
         } catch (_) {
+          if (!isCurrent()) return;
           // Session may have disconnected — clear indicator.
           const el = document.getElementById("status-latency");
           if (el) {
@@ -1389,18 +1421,24 @@
             el.className = "";
           }
           this._stopLatencyPing();
+        } finally {
+          if (isCurrent()) {
+            this._latencyPingInFlight = false;
+            if (succeeded) scheduleNext();
+          }
         }
       };
 
-      doPing();
+      void doPing();
-      this._latencyTimer = setInterval(doPing, 10000);
     }
 
     _stopLatencyPing() {
+      this._latencyGeneration = (this._latencyGeneration || 0) + 1;
       if (this._latencyTimer) {
-        clearInterval(this._latencyTimer);
+        clearTimeout(this._latencyTimer);
         this._latencyTimer = null;
       }
+      this._latencyPingInFlight = false;
       this._latencySessionID = null;
     }
 

go.mod

@@ -16,9 +16,9 @@ require (
 	github.com/ulikunitz/xz v0.5.15
 	github.com/wailsapp/wails/v2 v2.12.0
 	github.com/zalando/go-keyring v0.2.8
-	golang.org/x/crypto v0.52.0
+	golang.org/x/crypto v0.55.0
-	golang.org/x/net v0.55.0
+	golang.org/x/net v0.57.0
-	golang.org/x/text v0.37.0
+	golang.org/x/text v0.41.0
 	modernc.org/sqlite v1.53.0
 )
 
@@ -51,7 +51,7 @@ require (
 	github.com/valyala/fasttemplate v1.2.2 // indirect
 	github.com/wailsapp/go-webview2 v1.0.23 // indirect
 	github.com/wailsapp/mimetype v1.4.1 // indirect
-	golang.org/x/sys v0.45.0 // indirect
+	golang.org/x/sys v0.47.0 // indirect
 	modernc.org/libc v1.73.4 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.11.0 // indirect

go.sum

@@ -99,31 +99,31 @@ github.com/wailsapp/wails/v2 v2.12.0 h1:BHO/kLNWFHYjCzucxbzAYZWUjub1Tvb4cSguQozH
 github.com/wailsapp/wails/v2 v2.12.0/go.mod h1:mo1bzK1DEJrobt7YrBjgxvb5Sihb1mhAY09hppbibQg=
 github.com/zalando/go-keyring v0.2.8 h1:6sD/Ucpl7jNq10rM2pgqTs0sZ9V3qMrqfIIy5YPccHs=
 github.com/zalando/go-keyring v0.2.8/go.mod h1:tsMo+VpRq5NGyKfxoBVjCuMrG47yj8cmakZDO5QGii0=
-golang.org/x/crypto v0.52.0 h1:RMs7fP2rXdep0CftQlK8Uf+kibLm7qkCcradZWYz988=
+golang.org/x/crypto v0.55.0 h1:+KWHjbgOaAQ66dh/YlkZKHlz9ZUlq61AFirAR9ntP8M=
-golang.org/x/crypto v0.52.0/go.mod h1:1QgfPxDqh0T2M/elOJtp9RvuR95kVjir0e6/BvEmGbc=
+golang.org/x/crypto v0.55.0/go.mod h1:uq0V9dE/fzQuJtbnL+2EhWOE63vo164FY8xqEnV9xis=
-golang.org/x/mod v0.36.0 h1:JJjpVx6myfUsUdAzZuOSTTmRE0PfZeNWzzvKrP7amb4=
+golang.org/x/mod v0.38.0 h1:MECBjubtXD7yj4HrhIUcywNaGeNVUdfVnxmPajOk4yk=
-golang.org/x/mod v0.36.0/go.mod h1:moc6ELqsWcOw5Ef3xVprK5ul/MvtVvkIXLziUOICjUQ=
+golang.org/x/mod v0.38.0/go.mod h1:V6Xz0pq8TQ3dGqVQ1FVHuelZpAL0uNhSkk9ogYP3c40=
 golang.org/x/net v0.0.0-20210505024714-0287a6fb4125/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.55.0 h1:bcvxaJn3e1U6InsFWt1JUq1aSjnRxLzT2rtD2KfkDF8=
+golang.org/x/net v0.57.0 h1:K5+3DljvIuDG9/Jv9rvyMywYNFCQ9RSUY6OOTTkT+tE=
-golang.org/x/net v0.55.0/go.mod h1:L5U2KuzuOe1lY7Z+aWVIKK6qEeJXnXV9yzGA+WCHJww=
+golang.org/x/net v0.57.0/go.mod h1:KpXc8iv+r3XplLAG/f7Jsf9RPszJzdR0f58q9vGOuEU=
-golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
+golang.org/x/sync v0.22.0 h1:SZjpbeLmrCk4xhRSZFNZW5gFUeCeFgjekvI/+gfScek=
-golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+golang.org/x/sync v0.22.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
 golang.org/x/sys v0.0.0-20200810151505-1b9f1253b3ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20220712014510-0a85c31ab51e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
+golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
-golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.43.0 h1:S4RLU2sB31O/NCl+zFN9Aru9A/Cq2aqKpTZJ6B+DwT4=
+golang.org/x/term v0.45.0 h1:NwWyBmoJCbfTHpxrWoZ9C6/VxOf7ic219I8xZZFdrf0=
-golang.org/x/term v0.43.0/go.mod h1:lrhlHNdQJHO+1qVYiHfFKVuVioJIheAc3fBSMFYEIsk=
+golang.org/x/term v0.45.0/go.mod h1:9aqxs0blBcrm/n0L9QW0aRVD+ktan8ssZromtqJC43w=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.37.0 h1:Cqjiwd9eSg8e0QAkyCaQTNHFIIzWtidPahFWR83rTrc=
+golang.org/x/text v0.41.0 h1:vz/seA0lnX87Othu2f/0L24RcgrXD9/YFTSuGjj3rH8=
-golang.org/x/text v0.37.0/go.mod h1:a5sjxXGs9hsn/AJVwuElvCAo9v8QYLzvavO5z2PiM38=
+golang.org/x/text v0.41.0/go.mod h1:jvf1O8ajNzZqhSrQBPbutR/EB83Cc0CFrezNQIwbb5M=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.45.0 h1:18qN3FAooORvApf5XjCXgsuayZOEtXf6JK18I3+ONa8=
+golang.org/x/tools v0.48.0 h1:3+hClM1aLL5mjMKm5ovokw9epgRXPuu2tILgismM6RE=
-golang.org/x/tools v0.45.0/go.mod h1:LuUGqqaXcXMEFEruIVJVm5mgDD8vww/z/SR1gQ4uE/0=
+golang.org/x/tools v0.48.0/go.mod h1:08xX0orndb/F7jJxGDicx061tyd5pcMto75YMAXr6lk=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 modernc.org/cc/v4 v4.28.4 h1:Hd/4Es+MBj+/7hSdZaisNyu6bv3V0Dp2MdllyfqaH+c=

internal/sshclient/sshclient_test.go

@@ -1,6 +1,8 @@
 package sshclient
 
 import (
+	"crypto/ed25519"
+	"crypto/rand"
 	"net"
 	"testing"
 	"time"
@@ -57,3 +59,94 @@ func TestJumpHostClientConfigUsesFinalHostKeyCallback(t *testing.T) {
 		t.Fatal("final host key callback was not used")
 	}
 }
+
+func TestPingReturnsAfterSSHTransportCloses(t *testing.T) {
+	_, privateKey, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("GenerateKey() error = %v", err)
+	}
+	signer, err := ssh.NewSignerFromKey(privateKey)
+	if err != nil {
+		t.Fatalf("NewSignerFromKey() error = %v", err)
+	}
+
+	serverConfig := &ssh.ServerConfig{NoClientAuth: true}
+	serverConfig.AddHostKey(signer)
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("Listen() error = %v", err)
+	}
+	t.Cleanup(func() { _ = listener.Close() })
+
+	serverReady := make(chan *ssh.ServerConn, 1)
+	serverErrors := make(chan error, 1)
+	go func() {
+		conn, acceptErr := listener.Accept()
+		if acceptErr != nil {
+			serverErrors <- acceptErr
+			return
+		}
+		serverConn, _, _, handshakeErr := ssh.NewServerConn(conn, serverConfig)
+		if handshakeErr != nil {
+			_ = conn.Close()
+			serverErrors <- handshakeErr
+			return
+		}
+		serverReady <- serverConn
+	}()
+
+	conn, err := net.DialTimeout("tcp", listener.Addr().String(), 2*time.Second)
+	if err != nil {
+		t.Fatalf("DialTimeout() error = %v", err)
+	}
+	clientConn, channels, requests, err := ssh.NewClientConn(conn, listener.Addr().String(), &ssh.ClientConfig{
+		User:            "test",
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(), // Test server uses an ephemeral key.
+	})
+	if err != nil {
+		_ = conn.Close()
+		t.Fatalf("NewClientConn() error = %v", err)
+	}
+	rawClient := ssh.NewClient(clientConn, channels, requests)
+
+	var serverConn *ssh.ServerConn
+	select {
+	case serverConn = <-serverReady:
+	case serverErr := <-serverErrors:
+		t.Fatalf("SSH server handshake error = %v", serverErr)
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for SSH server handshake")
+	}
+
+	client := NewClient(&models.Profile{})
+	client.mu.Lock()
+	client.sshClient = rawClient
+	client.connected = true
+	client.mu.Unlock()
+	t.Cleanup(func() { _ = client.Close() })
+
+	if err := serverConn.Close(); err != nil {
+		t.Fatalf("server Close() error = %v", err)
+	}
+	waitDone := make(chan error, 1)
+	go func() { waitDone <- rawClient.Wait() }()
+	select {
+	case <-waitDone:
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for SSH transport to close")
+	}
+
+	pingDone := make(chan error, 1)
+	go func() {
+		_, pingErr := client.Ping()
+		pingDone <- pingErr
+	}()
+	select {
+	case pingErr := <-pingDone:
+		if pingErr == nil {
+			t.Fatal("Ping() succeeded after the SSH transport closed")
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("Ping() did not return after the SSH transport closed")
+	}
+}

scripts/linux-release.Dockerfile

@@ -0,0 +1,30 @@
+ARG GO_IMAGE
+FROM ${GO_IMAGE}
+
+ARG NODE_ARCH
+ARG NODE_VERSION
+ARG WAILS_VERSION
+
+ENV PATH="/opt/node/bin:/go/bin:/usr/local/go/bin:${PATH}"
+
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+        ca-certificates \
+        curl \
+        git \
+        libdigest-sha-perl \
+        libgtk-3-dev \
+        libwebkit2gtk-4.1-dev \
+        pkg-config \
+        xz-utils \
+        zip \
+    && node_archive="node-v${NODE_VERSION}-linux-${NODE_ARCH}.tar.xz" \
+    && curl -fsSLo "/tmp/${node_archive}" \
+        "https://nodejs.org/dist/v${NODE_VERSION}/${node_archive}" \
+    && mkdir -p /opt/node \
+    && tar -xJf "/tmp/${node_archive}" -C /opt/node --strip-components=1 \
+    && rm -f "/tmp/${node_archive}" \
+    && go install "github.com/wailsapp/wails/v2/cmd/wails@${WAILS_VERSION}" \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /src