k8s container id detection (#191)

update container detection to follow current best-practise, per bug report. we should check v1 then v2, and a few other updates I ripped off from java's implementation. adding tests for k8s and podman, and break inline content out into fixtures.
open-telemetry · Sep 15, 2023 · a973a41 · a973a41
1 parent e317b41
commit a973a41
Show file tree

Hide file tree

Showing 10 changed files with 217 additions and 23 deletions.
diff --git a/src/ResourceDetectors/Container/.php-cs-fixer.php b/src/ResourceDetectors/Container/.php-cs-fixer.php
@@ -20,7 +20,7 @@
     'blank_line_before_statement' => true,
     'cast_spaces' => true,
     'declare_strict_types' => true,
-    'function_typehint_space' => true,
+    'type_declaration_spaces' => true,
     'include' => true,
     'lowercase_cast' => true,
     'new_with_braces' => true,
@@ -34,7 +34,7 @@
     'phpdoc_scalar' => true,
     'phpdoc_types' => true,
     'short_scalar_cast' => true,
-    'single_blank_line_before_namespace' => true,
+    'blank_lines_before_namespace' => true,
     'single_quote' => true,
     'trailing_comma_in_multiline' => true,
     ])

diff --git a/src/ResourceDetectors/Container/README.md b/src/ResourceDetectors/Container/README.md
@@ -1,6 +1,7 @@
 # OpenTelemetry Container Detector
 
 This package provides an OpenTelemetry `ResourceDetector` which will detect docker container id at runtime, using either V1 (cgroup) or V2 (mountinfo).
+It should work with docker, kubernetes, and podman containers.
 
 ## Requirements
 

diff --git a/src/ResourceDetectors/Container/composer.json b/src/ResourceDetectors/Container/composer.json
@@ -10,7 +10,7 @@
   "prefer-stable": true,
   "require": {
     "php": "^7.0|^8.0",
-    "open-telemetry/sdk": ">= 1.0.0beta10"
+    "open-telemetry/sdk": ">= 1.0.0RC1 <= 2"
   },
   "autoload": {
     "psr-4": {

diff --git a/src/ResourceDetectors/Container/src/Container.php b/src/ResourceDetectors/Container/src/Container.php
@@ -11,11 +11,13 @@
 
 /**
  * @see https://github.com/open-telemetry/opentelemetry-specification/blob/v1.18.0/specification/resource/semantic_conventions/container.md
+ * @see https://github.com/open-telemetry/opentelemetry-java-instrumentation/blob/v1.29.0/instrumentation/resources/library/src/main/java/io/opentelemetry/instrumentation/resources/ContainerResource.java
  */
 final class Container implements ResourceDetectorInterface
 {
     private string $dir;
-    private const CONTAINER_ID_LENGTH = 64;
+    private const CONTAINER_ID_REGEX = '/^[0-9a-f]{64}$/';
+    private const V1_CONTAINER_ID_REGEX = '/\.?[0-9a-f]{64}\-?/';
     private const CGROUP_V1 = 'cgroup';
     private const CGROUP_V2 = 'mountinfo';
     private const HOSTNAME = 'hostname';
@@ -38,9 +40,14 @@ public function getResource(): ResourceInfo
 
     private function getContainerId(): ?string
     {
-        return $this->getContainerIdV2() ?? $this->getContainerIdV1();
+        return $this->getContainerIdV1() ?? $this->getContainerIdV2();
     }
 
+    /**
+     * Each line of cgroup file looks like "14:name=systemd:/docker/.../... A hex string is expected
+     * inside the last section separated by '/' Each segment of the '/' can contain metadata separated
+     * by either '.' (at beginning) or '-' (at end)
+     */
     private function getContainerIdV1(): ?string
     {
         if (!file_exists(sprintf('%s/%s', $this->dir, self::CGROUP_V1))) {
@@ -50,11 +57,20 @@ private function getContainerIdV1(): ?string
         if (!$data) {
             return null;
         }
-        $lines = explode('\n', $data);
+        $lines = explode(PHP_EOL, $data);
         foreach ($lines as $line) {
-            if (strlen($line) >= self::CONTAINER_ID_LENGTH) {
-                //if string is longer than CONTAINER_ID_LENGTH, return the last CONTAINER_ID_LENGTH chars
-                return substr($line, strlen($line) - self::CONTAINER_ID_LENGTH);
+            if (strpos($line, '/') === false) {
+                continue;
+            }
+            $parts = explode('/', $line);
+            $section = end($parts);
+            $colon = strrpos($section, ':');
+            if ($colon !== false) {
+                return substr($section, $colon);
+            }
+            $matches = [];
+            if (preg_match(self::V1_CONTAINER_ID_REGEX, $section, $matches) === 1) {
+                return $matches[0];
             }
         }
 
@@ -75,7 +91,7 @@ private function getContainerIdV2(): ?string
             if (strpos($line, self::HOSTNAME) !== false) {
                 $parts = explode('/', $line);
                 foreach ($parts as $part) {
-                    if (strlen($part) === self::CONTAINER_ID_LENGTH) {
+                    if (preg_match(self::CONTAINER_ID_REGEX, $part) === 1) {
                         return $part;
                     }
                 }

diff --git a/src/ResourceDetectors/Container/tests/Unit/ContainerTest.php b/src/ResourceDetectors/Container/tests/Unit/ContainerTest.php
@@ -25,15 +25,65 @@ public function setUp(): void
         $this->detector = new Container($root->url());
     }
 
-    public function test_valid_v1(): void
+    /**
+     * cgroup (v1) should take precedence over mountinfo (v2)
+     * @dataProvider cgroupMountinfoProvider
+     */
+    public function test_with_cgroup_and_mountinfo(string $cgroup, string $mountinfo, string $expected): void
     {
-        $valid = 'a8493b8a4f6f23b65c5db50be86619ca4da078da040aa3d5ccff26fe50de205d';
-        $this->cgroup->setContent($valid);
+        $cgroup && $this->cgroup->setContent($cgroup);
+        $mountinfo && $this->mountinfo->setContent($mountinfo);
+        $resource = $this->detector->getResource();
+
+        $this->assertSame($expected, $resource->getAttributes()->get(ResourceAttributes::CONTAINER_ID));
+    }
+
+    public static function cgroupMountinfoProvider(): array
+    {
+        return [
+            'k8s' => [
+                file_get_contents(__DIR__ . '/fixtures/v1.cgroup.k8s.txt'),
+                file_get_contents(__DIR__ . '/fixtures/v2.mountinfo.k8s.txt'),
+                '78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075',
+            ],
+            'docker with invalid cgroup' => [
+                'no-container-ids-here',
+                file_get_contents(__DIR__ . '/fixtures/v2.mountinfo.docker.txt'),
+                'a8493b8a4f6f23b65c5db50be86619ca4da078da040aa3d5ccff26fe50de205d',
+            ],
+            'podman' => [
+                'no-container-ids-here',
+                file_get_contents(__DIR__ . '/fixtures/v2.mountinfo.podman.txt'),
+                '2a33efc76e519c137fe6093179653788bed6162d4a15e5131c8e835c968afbe6',
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider cgroupProvider
+     */
+    public function test_valid_v1(string $data, string $expected): void
+    {
+        $this->cgroup->setContent($data);
         $resource = $this->detector->getResource();
 
         $this->assertSame(ResourceAttributes::SCHEMA_URL, $resource->getSchemaUrl());
         $this->assertIsString($resource->getAttributes()->get(ResourceAttributes::CONTAINER_ID));
-        $this->assertSame($valid, $resource->getAttributes()->get(ResourceAttributes::CONTAINER_ID));
+        $this->assertSame($expected, $resource->getAttributes()->get(ResourceAttributes::CONTAINER_ID));
+    }
+
+    public static function cgroupProvider(): array
+    {
+        return [
+            'docker' => [
+                file_get_contents(__DIR__ . '/fixtures/v1.cgroup.docker.txt'),
+                '7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605',
+            ],
+            'k8s' => [
+                file_get_contents(__DIR__ . '/fixtures/v1.cgroup.k8s.txt'),
+                '78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075',
+            ],
+        ];
     }
 
     public function test_invalid_v1(): void
@@ -44,23 +94,32 @@ public function test_invalid_v1(): void
         $this->assertEmpty($resource->getAttributes());
     }
 
-    public function test_valid_v2(): void
+    /**
+     * @dataProvider mountinfoProvider
+     */
+    public function test_valid_v2(string $data, string $expected): void
     {
-        $expected = 'a8493b8a4f6f23b65c5db50be86619ca4da078da040aa3d5ccff26fe50de205d';
-        $data = <<< EOS
-1366 1365 0:30 / /sys/fs/cgroup ro,nosuid,nodev,noexec,relatime - cgroup2 cgroup rw
-1408 1362 0:107 / /dev/mqueue rw,nosuid,nodev,noexec,relatime - mqueue mqueue rw
-1579 1362 0:112 / /dev/shm rw,nosuid,nodev,noexec,relatime - tmpfs shm rw,size=65536k,inode64
-1581 1359 259:2 /var/lib/docker/containers/a8493b8a4f6f23b65c5db50be86619ca4da078da040aa3d5ccff26fe50de205d/hostname /etc/hostname rw,relatime - ext4 /dev/nvme0n1p2 rw,errors=remount-ro
-1583 1359 259:3 /brett/docker/otel/opentelemetry-php /usr/src/myapp rw,relatime - ext4 /dev/nvme0n1p3 rw
-EOS;
         $this->mountinfo->withContent($data);
         $resource = $this->detector->getResource();
 
         $this->assertCount(1, $resource->getAttributes());
         $this->assertSame($expected, $resource->getAttributes()->get(ResourceAttributes::CONTAINER_ID));
     }
 
+    public static function mountinfoProvider(): array
+    {
+        return [
+            'docker' => [
+                file_get_contents(__DIR__ . '/fixtures/v2.mountinfo.docker.txt'),
+                'a8493b8a4f6f23b65c5db50be86619ca4da078da040aa3d5ccff26fe50de205d',
+            ],
+            'podman' => [
+                file_get_contents(__DIR__ . '/fixtures/v2.mountinfo.podman.txt'),
+                '2a33efc76e519c137fe6093179653788bed6162d4a15e5131c8e835c968afbe6',
+            ],
+        ];
+    }
+
     public function test_invalid_v2(): void
     {
         $data = <<< EOS

diff --git a/src/ResourceDetectors/Container/tests/Unit/fixtures/v1.cgroup.docker.txt b/src/ResourceDetectors/Container/tests/Unit/fixtures/v1.cgroup.docker.txt
@@ -0,0 +1,14 @@
+14:name=systemd:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+13:pids:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+12:hugetlb:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+11:net_prio:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+10:perf_event:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+9:net_cls:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+8:freezer:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+7:devices:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+6:memory:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+5:blkio:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+4:cpuacct:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+3:cpu:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+2:cpuset:/docker/7be92808767a667f35c8505cbf40d14e931ef6db5b0210329cf193b15ba9d605
+1:name=openrc:/docker
diff --git a/src/ResourceDetectors/Container/tests/Unit/fixtures/v1.cgroup.k8s.txt b/src/ResourceDetectors/Container/tests/Unit/fixtures/v1.cgroup.k8s.txt
@@ -0,0 +1,13 @@
+13:devices:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+12:pids:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+11:perf_event:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+10:freezer:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+9:cpuset:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+8:hugetlb:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+7:rdma:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+6:misc:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+5:memory:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+4:cpu,cpuacct:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+3:blkio:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+2:net_cls,net_prio:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
+1:name=systemd:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod542985b6_0726_4d82_bf85_36e327b167b3.slice/crio-78ea929aa43e7b71f7c36583d82038d92a76800bf5da9b8850e8bd7b514bc075.scope
diff --git a/src/ResourceDetectors/Container/tests/Unit/fixtures/v2.mountinfo.docker.txt b/src/ResourceDetectors/Container/tests/Unit/fixtures/v2.mountinfo.docker.txt
@@ -0,0 +1,5 @@
+1366 1365 0:30 / /sys/fs/cgroup ro,nosuid,nodev,noexec,relatime - cgroup2 cgroup rw
+1408 1362 0:107 / /dev/mqueue rw,nosuid,nodev,noexec,relatime - mqueue mqueue rw
+1579 1362 0:112 / /dev/shm rw,nosuid,nodev,noexec,relatime - tmpfs shm rw,size=65536k,inode64
+1581 1359 259:2 /var/lib/docker/containers/a8493b8a4f6f23b65c5db50be86619ca4da078da040aa3d5ccff26fe50de205d/hostname /etc/hostname rw,relatime - ext4 /dev/nvme0n1p2 rw,errors=remount-ro
+1583 1359 259:3 /brett/docker/otel/opentelemetry-php /usr/src/myapp rw,relatime - ext4 /dev/nvme0n1p3 rw