wip

Author: timacdonald

agent/box.json.dist

@@ -1,4 +1,5 @@
 {
+    "$schema": "https://raw.githubusercontent.com/box-project/box/refs/heads/main/res/schema.json",
     "main": "src/agent.php",
     "output": "build/agent.phar",
     "alias": "nightwatch-agent.phar",

agent/build/agent.phar

@@ -1 +1 @@
-EA7F6BABFE0D3F3B53FEE7E9C5F2E657FAF8CA6156CC92AF7ADC0F750930A98963BC7BB69056C010F4A5B77B4B53C064618A53DE62B1B482A2D75EAEDA38B682
+C0978882D751DC34E15523FF52762FD07A38E47F79482287AFAEABF1CB797FBF38747687A11CE7C65BA97F7F682A8683E58EDA5AD509E84F981354F675858369

agent/build/signature.txt

@@ -54,6 +54,7 @@ public function write(string $payload): void
             $this->ingest($records);
         } elseif ($this->buffer->isNotEmpty()) {
             $this->flushBufferAfterDelayTimer ??= Loop::addTimer($this->maxBufferDurationInSeconds, function (): void {
+                // TODO Must not throw an exception
                 $records = $this->buffer->flush();
 
                 $this->flushBufferAfterDelayTimer = null;

agent/src/Ingest.php

@@ -114,6 +114,7 @@ private function scheduleRefreshIn(int $seconds): void
         $seconds = max($this->minRefreshDurationInSeconds, $seconds);
 
         Loop::addTimer($seconds, function (): void {
+            // TODO must not throw an exception
             $this->refresh()->then(function (?IngestDetails $ingestDetails): void {
                 $this->ingestDetails = resolve($ingestDetails);
             });

agent/src/IngestDetailsRepository.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Laravel\NightwatchAgent;
+
+use Closure;
+use React\EventLoop\Loop;
+use RuntimeException;
+
+use function call_user_func;
+use function file_get_contents;
+use function trim;
+
+class Signature
+{
+    private string $signature;
+
+    /**
+     * @param  (Closure(string $before, string $after): mixed)  $onChange
+     */
+    public function __construct(
+        private string $path,
+        private int $verificationIntervalInSeconds,
+        private Closure $onChange,
+    ) {
+        //
+    }
+
+    public function capture(): void
+    {
+        $signature = file_get_contents($this->path);
+
+        if ($signature === false) {
+            throw new RuntimeException('Unable to read the signature file');
+        }
+
+        if (trim($signature) === '') {
+            throw new RuntimeException('Signature file is empty');
+        }
+
+        $this->signature = $signature;
+
+        Loop::addPeriodicTimer($this->verificationIntervalInSeconds, function () {
+            // TODO must not throw an exception
+            $this->verify(...);
+        });
+    }
+
+    private function verify(): void
+    {
+        $newSignature = file_get_contents($this->path);
+
+        if ($newSignature === false) {
+            throw new RuntimeException('Unable to verify the signature file');
+        }
+
+        if ($this->signature !== $newSignature) {
+            call_user_func($this->onChange, $this->signature, $newSignature);
+        }
+    }
+}

agent/src/Signature.php

@@ -75,8 +75,8 @@
     minRefreshDurationInSeconds: 60,
     server: $server,
     packageVersion: $packageVersion,
-    onAuthenticationSuccess: static fn (IngestDetails $ingestDetails, float $duration) => $info('Authentication successful ['.round($duration, 3).'s]'),
-    onAuthenticationError: static fn (Throwable $e, float $duration) => $info('Authentication failed ['.round($duration, 3).'s]: '.$e->getMessage()),
+    onAuthenticationSuccess: static fn (IngestDetails $ingestDetails, float $duration) => $info('Authentication successful against ['.$baseUrl.'] ['.round($duration, 3).'s]'),
+    onAuthenticationError: static fn (Throwable $e, float $duration) => $info('Authentication failed against ['.$baseUrl.'] ['.round($duration, 3).'s]: '.$e->getMessage()),
 );
 
 $ingest = (new IngestFactory)(
@@ -95,16 +95,28 @@
 
 $server = (new ServerFactory)(
     listenOn: $listenOn,
-    onServerStarted: static fn () => $info("Nightwatch agent initiated: Listening on [{$listenOn}]."),
+    onServerStarted: static fn () => $info("Nightwatch agent initiated: Listening on [{$listenOn}]"),
     onServerError: static fn (Throwable $e) => $error("Server error: {$e->getMessage()}"),
     onConnectionError: static fn (Throwable $e) => $error("Connection error: {$e->getMessage()}"),
     onPayloadReceived: $ingest->write(...),
 );
 
+$signature = new Signature(
+    path: $basePath.'/signature.txt',
+    verificationIntervalInSeconds: 5,
+    onChange: static function (string $before, string $after) use ($info) {
+        $info("Restarting the agent as the signature has changed [{$before}] [{$after}]");
+
+        Loop::stop();
+    },
+);
+
 /*
  * Get things rolling...
  */
 
+$signature->capture();
+
 $server->start();
 
 $ingestDetails->hydrate();

agent/src/agent.php

@@ -0,0 +1,13 @@
+<?php
+
+use Laravel\NightwatchAgent\Signature;
+
+it('throws an exception if the signature file does not exist', function () {
+    $signature = new Signature(
+        path: __DIR__.'/file-that-does-not-exist',
+        verificationIntervalInSeconds: 1,
+        onChange: fn () => null,
+    );
+
+    $signature->capture();
+})->throws(RuntimeException::class);

agent/tests/Unit/SignatureTest.php

@@ -1,4 +1,5 @@
 {
+    "$schema": "https://raw.githubusercontent.com/box-project/box/refs/heads/main/res/schema.json",
     "main": "src/client.php",
     "output": "build/client.phar",
     "alias": "nightwatch-client.phar",

client/box.json.dist

@@ -0,0 +1,6 @@
+# Restart
+
+- There is not really any need to restart on every deployment. It would be detrimental to data collection process to do so unless:
+    - The agent has changed.
+    - The agent has received data it no longer understands, e.g, a payload version change.
+    - Environment variables / configuration variables that the agent requires has changed. Currently this is only the `NIGHTWATCH_TOKEN` which is unlikely to change enough to make restarting on every deploy worth it.