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fix(liveness): skip self.close() on SIGTERM during HMR/watch #1212

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fix(liveness): skip self.close() on SIGTERM during HMR/watch #1212

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12 changes: 11 additions & 1 deletion runtime/middlewares/liveness.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -65,12 +65,22 @@ const buildHandler = (
}
});
};
// In production (k8s), SIGTERM comes from the kubelet and the process must
// shut down. In local dev, Deno's HMR/watch sends SIGTERM to the child
// process expecting a clean restart cycle — calling self.close() here kills
// the process before HMR can relaunch it, breaking hot-reload entirely.
// Deno runtime flags (--unstable-hmr, --watch) are NOT visible in Deno.args,
// so we detect production by the presence of KUBERNETES_SERVICE_HOST which is
// always injected into k8s pods.
const isK8s = Boolean(Deno.env.get("KUBERNETES_SERVICE_HOST"));
try {
if (Deno.build.os !== "windows") {
Deno.addSignalListener("SIGTERM", () => {
const checks = runChecks();
console.log(checks);
self.close();
if (isK8s) {
self.close();
Comment on lines +75 to +82

@coderabbitai coderabbitai Bot Jun 25, 2026

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🩺 Stability & Availability | 🟠 Major | ⚡ Quick win

Don't use Kubernetes presence as the shutdown default.

Lines 75-82 now change SIGTERM behavior from “close unless we're in watch/HMR” to “close only in Kubernetes”. That widens the behavior change to every non-k8s runtime, so ordinary production deployments outside Kubernetes will now skip self.close() too. The exception should be keyed off the specific dev/watch mode, with self.close() remaining the default for normal SIGTERM handling.

Suggested change 
-  const isK8s = Boolean(Deno.env.get("KUBERNETES_SERVICE_HOST"));
+  const isWatchMode = Deno.env.get("DECO_WATCH_MODE") === "1";
   try {
     if (Deno.build.os !== "windows") {
       Deno.addSignalListener("SIGTERM", () => {
         const checks = runChecks();
         console.log(checks);
-        if (isK8s) {
+        if (!isWatchMode) {
           self.close();
         }
       });
     }
   } catch (err) {
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
const isK8s = Boolean(Deno.env.get("KUBERNETES_SERVICE_HOST"));
try {
if (Deno.build.os !== "windows") {
Deno.addSignalListener("SIGTERM", () => {
const checks = runChecks();
console.log(checks);
self.close();
if (isK8s) {
self.close();
const isWatchMode = Deno.env.get("DECO_WATCH_MODE") === "1";
try {
if (Deno.build.os !== "windows") {
Deno.addSignalListener("SIGTERM", () => {
const checks = runChecks();
console.log(checks);
if (!isWatchMode) {
self.close();
🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@runtime/middlewares/liveness.ts` around lines 75 - 82, The SIGTERM handler in
liveness.ts now gates self.close() on Kubernetes detection, which makes non-K8s
production skips the default shutdown path. Update the logic in the SIGTERM
listener so the exception is based on the specific dev/watch/HMR mode instead of
isK8s, and keep self.close() as the default behavior for normal shutdown
handling in runChecks()/Deno.addSignalListener.

}
});
}
} catch (err) {
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