[4.x] Prevent horizon:purge from killing too many processes

src/MasterSupervisor.php

@@ -96,9 +96,11 @@ public static function name()
      */
     public static function basename()
     {
+        $pathHash = substr(md5(__DIR__), 0, 4);
+
         return static::$nameResolver
-                        ? call_user_func(static::$nameResolver)
-                        : Str::slug(gethostname());
+                        ? call_user_func(static::$nameResolver).'-'.$pathHash
+                        : Str::slug(gethostname()).'-'.$pathHash;
     }
 
     /**

src/ProcessInspector.php

@@ -33,10 +33,9 @@ public function __construct(Exec $exec)
      */
     public function current()
     {
-        return array_diff(
-            $this->exec->run('pgrep -f [h]orizon'),
-            $this->exec->run('pgrep -f horizon:purge')
-        );
+        $supervisorBasename = MasterSupervisor::basename();
+
+        return $this->exec->run("pgrep -f '[h]orizon.*[ =]{$supervisorBasename}-'");
     }
 
     /**
@@ -46,17 +45,27 @@ public function current()
      */
     public function orphaned()
     {
-        return array_diff($this->current(), $this->monitoring());
+        return array_diff(
+            array_merge($this->current(), $this->mastersWithoutSupervisors()),
+            $this->validMonitoring()
+        );
     }
 
     /**
-     * Get all of the process IDs Horizon is actively monitoring.
+     * Get all of the process IDs that Horizon is actively monitoring and that are valid. For master processes "valid"
+     * means they have child processes (supervisors). For supervisors it means their parent processes (masters) exist.
      *
      * @return array
      */
-    public function monitoring()
+    public function validMonitoring()
     {
+        $masters = $this->monitoredMastersWithSupervisors();
+        $masterNames = array_flip(Arr::pluck($masters, 'name'));
+
         return collect(app(SupervisorRepository::class)->all())
+            ->filter(function ($supervisor) use (&$masterNames) {
+                return isset($masterNames[data_get($supervisor, 'master')]);
+            })
             ->pluck('pid')
             ->pipe(function ($processes) {
                 $processes->each(function ($process) use (&$processes) {
@@ -65,8 +74,36 @@ public function monitoring()
 
                 return $processes;
             })
-            ->merge(
-                Arr::pluck(app(MasterSupervisorRepository::class)->all(), 'pid')
-            )->all();
+            ->merge(Arr::pluck($masters, 'pid'))
+            ->all();
+    }
+
+    /**
+     * Get data of master processes that have child processes (supervisors) and are monitored by Horizon.
+     *
+     * @return array
+     */
+    public function monitoredMastersWithSupervisors()
+    {
+        return collect(app(MasterSupervisorRepository::class)->all())->filter(function ($master) {
+            return ! empty($this->exec->run('pgrep -P '.data_get($master, 'pid')));
+        })
+            ->values()
+            ->all();
+    }
+
+    /**
+     * Get IDs of all master Horizon processes that don't have any supervisors.
+     *
+     * @return array
+     */
+    public function mastersWithoutSupervisors()
+    {
+        return collect($this->exec->run('pgrep -f [h]orizon$'))
+            ->filter(function ($pid) {
+                return empty($this->exec->run('pgrep -P '.$pid));
+            })
+            ->values()
+            ->all();
     }
 }

tests/Feature/ProcessInspectorTest.php

@@ -5,6 +5,7 @@
 use Laravel\Horizon\Contracts\MasterSupervisorRepository;
 use Laravel\Horizon\Contracts\SupervisorRepository;
 use Laravel\Horizon\Exec;
+use Laravel\Horizon\MasterSupervisor;
 use Laravel\Horizon\ProcessInspector;
 use Laravel\Horizon\Tests\IntegrationTest;
 use Mockery;
@@ -14,8 +15,10 @@ class ProcessInspectorTest extends IntegrationTest
     public function test_finds_orphaned_process_ids()
     {
         $exec = Mockery::mock(Exec::class);
-        $exec->shouldReceive('run')->with('pgrep -f [h]orizon')->andReturn([1, 2, 3, 4, 5, 6]);
-        $exec->shouldReceive('run')->with('pgrep -f horizon:purge')->andReturn([]);
+        $exec->shouldReceive('run')->with(Mockery::pattern('/^pgrep -f \'\[h\]orizon\.\*\[ =\]/'))
+            ->andReturn([1, 2, 3, 4, 5, 6]);
+        $exec->shouldReceive('run')->with('pgrep -f [h]orizon$')->andReturn([6]);
+        $exec->shouldReceive('run')->with('pgrep -P 6')->andReturn([2, 3]);
         $exec->shouldReceive('run')->with('pgrep -P 2')->andReturn([4]);
         $exec->shouldReceive('run')->with('pgrep -P 3')->andReturn([5]);
         $this->app->instance(Exec::class, $exec);
@@ -24,9 +27,11 @@ public function test_finds_orphaned_process_ids()
         $supervisors->shouldReceive('all')->andReturn([
             [
                 'pid' => 2,
+                'master' => 'test',
             ],
             [
                 'pid' => 3,
+                'master' => 'test',
             ],
         ]);
         $this->app->instance(SupervisorRepository::class, $supervisors);
@@ -35,6 +40,7 @@ public function test_finds_orphaned_process_ids()
         $masters->shouldReceive('all')->andReturn([
             [
                 'pid' => 6,
+                'name' => 'test',
             ],
         ]);
         $this->app->instance(MasterSupervisorRepository::class, $masters);
@@ -43,4 +49,55 @@ public function test_finds_orphaned_process_ids()
 
         $this->assertEquals([1], $inspector->orphaned());
     }
+
+    public function test_it_uses_master_supervisor_basename_to_find_current_processes()
+    {
+        $exec = Mockery::mock(Exec::class);
+        $this->app->instance(Exec::class, $exec);
+        $masterBasename = MasterSupervisor::basename();
+        $exec->shouldReceive('run')->with(Mockery::pattern("/pgrep -f '\[h\]orizon\.\*\[ =\].*{$masterBasename}-'/"))
+            ->andReturn([1]);
+
+        $this->assertEquals([1], resolve(ProcessInspector::class)->current());
+    }
+
+    public function test_it_finds_monitored_masters_that_have_supervisor_processes()
+    {
+        $exec = Mockery::mock(Exec::class);
+        $this->app->instance(Exec::class, $exec);
+        $exec->shouldReceive('run')->with('pgrep -P 3')->andReturn([1, 2]);
+        $exec->shouldReceive('run')->with('pgrep -P 4')->andReturn([]);
+
+        $masters = Mockery::mock(MasterSupervisorRepository::class);
+        $this->app->instance(MasterSupervisorRepository::class, $masters);
+        $masters->shouldReceive('all')->andReturn([
+            [
+                'pid' => 3,
+            ],
+            [
+                'pid' => 4,
+            ],
+        ]);
+
+        $inspector = resolve(ProcessInspector::class);
+
+        $this->assertEquals([
+            [
+                'pid' => 3,
+            ],
+        ], $inspector->monitoredMastersWithSupervisors());
+    }
+
+    public function test_it_finds_master_processes_without_supervisor_child_processes()
+    {
+        $exec = Mockery::mock(Exec::class);
+        $this->app->instance(Exec::class, $exec);
+        $exec->shouldReceive('run')->with('pgrep -f [h]orizon$')->andReturn([1, 2]);
+        $exec->shouldReceive('run')->with('pgrep -P 1')->andReturn([[3, 4]]);
+        $exec->shouldReceive('run')->with('pgrep -P 2')->andReturn([]);
+
+        $inspector = resolve(ProcessInspector::class);
+
+        $this->assertEquals([2], $inspector->mastersWithoutSupervisors());
+    }
 }