From bb9eb40a5033abb2157994e087fdc6dd0a3cc559 Mon Sep 17 00:00:00 2001
From: Matt Hensley <130569+matt-hensley@users.noreply.github.com>
Date: Mon, 1 Apr 2024 18:20:09 -0400
Subject: [PATCH] Add host.id for non-containerized systems (#1266)

Co-authored-by: Tobias Bachert <git@b-privat.de>
Co-authored-by: Chris Lightfoot-Wild <github-clw@wild.me.uk>
---
 src/SDK/Resource/Detectors/Host.php           | 72 +++++++++++++++++++
 .../Unit/SDK/Resource/Detectors/HostTest.php  | 53 ++++++++++++++
 2 files changed, 125 insertions(+)

diff --git a/src/SDK/Resource/Detectors/Host.php b/src/SDK/Resource/Detectors/Host.php
index dd2554540..af5082778 100644
--- a/src/SDK/Resource/Detectors/Host.php
+++ b/src/SDK/Resource/Detectors/Host.php
@@ -15,13 +15,85 @@
  */
 final class Host implements ResourceDetectorInterface
 {
+    private const PATH_ETC_MACHINEID = 'etc/machine-id';
+    private const PATH_VAR_LIB_DBUS_MACHINEID = 'var/lib/dbus/machine-id';
+    private const PATH_ETC_HOSTID = 'etc/hostid';
+
+    public function __construct(
+        private readonly string $dir = '/',
+        private readonly string $os = PHP_OS_FAMILY,
+    ) {
+    }
+
     public function getResource(): ResourceInfo
     {
         $attributes = [
             ResourceAttributes::HOST_NAME => php_uname('n'),
             ResourceAttributes::HOST_ARCH => php_uname('m'),
+            ResourceAttributes::HOST_ID => $this->getMachineId(),
         ];
 
         return ResourceInfo::create(Attributes::create($attributes), ResourceAttributes::SCHEMA_URL);
     }
+
+    private function getMachineId(): ?string
+    {
+        return match ($this->os) {
+            'Linux' => $this->getLinuxId(),
+            'BSD' => $this->getBsdId(),
+            'Darwin' => $this->getMacOsId(),
+            'Windows' => $this->getWindowsId(),
+            default => null,
+        };
+    }
+
+    private function getLinuxId(): ?string
+    {
+        $paths = [self::PATH_ETC_MACHINEID, self::PATH_VAR_LIB_DBUS_MACHINEID];
+
+        foreach ($paths as $path) {
+            if (file_exists($this->dir . $path)) {
+                return trim(file_get_contents($this->dir . $path));
+            }
+        }
+
+        return null;
+    }
+
+    private function getBsdId(): ?string
+    {
+        if (file_exists($this->dir . self::PATH_ETC_HOSTID)) {
+            return trim(file_get_contents($this->dir . self::PATH_ETC_HOSTID));
+        }
+
+        $out = exec('kenv -q smbios.system.uuid');
+
+        if ($out != false) {
+            return $out;
+        }
+
+        return null;
+    }
+
+    private function getMacOsId(): ?string
+    {
+        $out = exec('ioreg -rd1 -c IOPlatformExpertDevice | awk \'/IOPlatformUUID/ { split($0, line, "\""); printf("%s\n", line[4]); }\'');
+
+        if ($out != false) {
+            return $out;
+        }
+
+        return null;
+    }
+
+    private function getWindowsId(): ?string
+    {
+        $out = exec('powershell.exe -Command "Get-ItemPropertyValue -Path HKLM:\SOFTWARE\Microsoft\Cryptography -Name MachineGuid"');
+
+        if ($out != false) {
+            return $out;
+        }
+
+        return null;
+    }
 }
diff --git a/tests/Unit/SDK/Resource/Detectors/HostTest.php b/tests/Unit/SDK/Resource/Detectors/HostTest.php
index 9264dc0e6..2bcddfddd 100644
--- a/tests/Unit/SDK/Resource/Detectors/HostTest.php
+++ b/tests/Unit/SDK/Resource/Detectors/HostTest.php
@@ -6,6 +6,7 @@
 
 use OpenTelemetry\SDK\Resource\Detectors;
 use OpenTelemetry\SemConv\ResourceAttributes;
+use org\bovigo\vfs\vfsStream;
 use PHPUnit\Framework\TestCase;
 
 /**
@@ -22,4 +23,56 @@ public function test_host_get_resource(): void
         $this->assertIsString($resource->getAttributes()->get(ResourceAttributes::HOST_NAME));
         $this->assertIsString($resource->getAttributes()->get(ResourceAttributes::HOST_ARCH));
     }
+
+    /**
+     * @dataProvider hostIdData
+     */
+    public function test_host_id_filesystem(string $os, array $files, ?string $expectedId): void
+    {
+        $root = vfsStream::setup('/', null, $files);
+        $resouceDetector = new Detectors\Host($root->url(), $os);
+        $resource = $resouceDetector->getResource();
+
+        if ($expectedId === null) {
+            $this->assertFalse($resource->getAttributes()->has(ResourceAttributes::HOST_ID));
+
+            return;
+        }
+
+        $hostId = $resource->getAttributes()->get(ResourceAttributes::HOST_ID);
+        $this->assertIsString($hostId);
+        $this->assertSame($expectedId, $hostId);
+    }
+
+    public static function hostIdData(): array
+    {
+        $etc_machineid = [
+            'etc' => [
+                'machine-id' => '1234567890',
+            ],
+        ];
+        $varLibDbus = [
+            'var' => [
+                'lib' => [
+                    'dbus' => [
+                        'machine-id' => '0987654321',
+                    ],
+                ],
+            ],
+        ];
+        $etc_hostid = [
+            'etc' => [
+                'hostid' => '1234567890',
+            ],
+        ];
+
+        return [
+            ['Linux', [], null],
+            ['Linux', $etc_machineid, '1234567890'],
+            ['Linux', array_merge($etc_machineid, $varLibDbus), '1234567890'],
+            ['Linux', $etc_machineid, '1234567890'],
+            ['BSD', [], null],
+            ['BSD', $etc_hostid, '1234567890'],
+        ];
+    }
 }