Support cgroup v2 (#7167)

This resolves #6694. We've been tracking the update to cgroup version support and want to get ahead of the widespread usage. The surface of the existing `ContainerResource` has not changed, but its internals have been factored out to two "extractor" utilities -- one that understands cgroup v1 and another for v2. v1 is attempted and, if successful, the result is used. If v1 fails, then the `ContainerResource` will fall back to v2. As mentioned in #6694, the approach taken in this PR is borrowed from [this SO post](https://stackoverflow.com/questions/68816329/how-to-get-docker-container-id-from-within-the-container-with-cgroup-v2) combined with local experimentation on docker desktop on a Mac, which already uses cgroup2 v2.
open-telemetry · Nov 15, 2022 · b09fb67 · b09fb67
1 parent 33b0b58
commit b09fb67
Showing 6 changed files with 395 additions and 148 deletions.
diff --git a/...rc/main/java/io/opentelemetry/instrumentation/resources/CgroupV1ContainerIdExtractor.java b/...rc/main/java/io/opentelemetry/instrumentation/resources/CgroupV1ContainerIdExtractor.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.resources;
+
+import io.opentelemetry.api.internal.OtelEncodingUtils;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Optional;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
+
+/** Utility for extracting the container ID from runtimes inside cgroup v1 containers. */
+final class CgroupV1ContainerIdExtractor {
+
+  private static final Logger logger =
+      Logger.getLogger(CgroupV1ContainerIdExtractor.class.getName());
+  static final Path V1_CGROUP_PATH = Paths.get("/proc/self/cgroup");
+  private final ContainerResource.Filesystem filesystem;
+
+  CgroupV1ContainerIdExtractor() {
+    this(ContainerResource.FILESYSTEM_INSTANCE);
+  }
+
+  // Exists for testing
+  CgroupV1ContainerIdExtractor(ContainerResource.Filesystem filesystem) {
+    this.filesystem = filesystem;
+  }
+
+  /**
+   * 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)
+   *
+   * @return containerId
+   */
+  Optional<String> extractContainerId() {
+    if (!filesystem.isReadable(V1_CGROUP_PATH)) {
+      return Optional.empty();
+    }
+    try (Stream<String> lines = filesystem.lines(V1_CGROUP_PATH)) {
+      return lines
+          .filter(line -> !line.isEmpty())
+          .map(CgroupV1ContainerIdExtractor::getIdFromLine)
+          .filter(Optional::isPresent)
+          .findFirst()
+          .orElse(Optional.empty());
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Unable to read file", e);
+    }
+    return Optional.empty();
+  }
+
+  private static Optional<String> getIdFromLine(String line) {
+    // This cgroup output line should have the container id in it
+    int lastSlashIdx = line.lastIndexOf('/');
+    if (lastSlashIdx < 0) {
+      return Optional.empty();
+    }
+
+    String containerId;
+
+    String lastSection = line.substring(lastSlashIdx + 1);
+    int colonIdx = lastSection.lastIndexOf(':');
+
+    if (colonIdx != -1) {
+      // since containerd v1.5.0+, containerId is divided by the last colon when the cgroupDriver is
+      // systemd:
+      // https://github.com/containerd/containerd/blob/release/1.5/pkg/cri/server/helpers_linux.go#L64
+      containerId = lastSection.substring(colonIdx + 1);
+    } else {
+      int startIdx = lastSection.lastIndexOf('-');
+      int endIdx = lastSection.lastIndexOf('.');
+
+      startIdx = startIdx == -1 ? 0 : startIdx + 1;
+      if (endIdx == -1) {
+        endIdx = lastSection.length();
+      }
+      if (startIdx > endIdx) {
+        return Optional.empty();
+      }
+
+      containerId = lastSection.substring(startIdx, endIdx);
+    }
+
+    if (OtelEncodingUtils.isValidBase16String(containerId) && !containerId.isEmpty()) {
+      return Optional.of(containerId);
+    } else {
+      return Optional.empty();
+    }
+  }
+}
diff --git a/...rc/main/java/io/opentelemetry/instrumentation/resources/CgroupV2ContainerIdExtractor.java b/...rc/main/java/io/opentelemetry/instrumentation/resources/CgroupV2ContainerIdExtractor.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.resources;
+
+import static java.util.Optional.empty;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Optional;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/** Utility for extracting the container ID from runtimes inside cgroup v2 containers. */
+class CgroupV2ContainerIdExtractor {
+
+  private static final Logger logger =
+      Logger.getLogger(CgroupV2ContainerIdExtractor.class.getName());
+
+  static final Path V2_CGROUP_PATH = Paths.get("/proc/self/mountinfo");
+  private static final Pattern CONTAINER_RE =
+      Pattern.compile(".*/docker/containers/([0-9a-f]{64})/.*");
+
+  private final ContainerResource.Filesystem filesystem;
+
+  CgroupV2ContainerIdExtractor() {
+    this(ContainerResource.FILESYSTEM_INSTANCE);
+  }
+
+  // Exists for testing
+  CgroupV2ContainerIdExtractor(ContainerResource.Filesystem filesystem) {
+    this.filesystem = filesystem;
+  }
+
+  Optional<String> extractContainerId() {
+    if (!filesystem.isReadable(V2_CGROUP_PATH)) {
+      return empty();
+    }
+    try {
+      return filesystem
+          .lines(V2_CGROUP_PATH)
+          .map(CONTAINER_RE::matcher)
+          .filter(Matcher::matches)
+          .findFirst()
+          .map(matcher -> matcher.group(1));
+    } catch (IOException e) {
+      logger.log(Level.WARNING, "Unable to read v2 cgroup path", e);
+    }
+    return empty();
+  }
+}
diff --git a/...s/library/src/main/java/io/opentelemetry/instrumentation/resources/ContainerResource.java b/...s/library/src/main/java/io/opentelemetry/instrumentation/resources/ContainerResource.java
@@ -5,106 +5,75 @@
 
 package io.opentelemetry.instrumentation.resources;
 
+import static io.opentelemetry.semconv.resource.attributes.ResourceAttributes.CONTAINER_ID;
+
+import com.google.errorprone.annotations.MustBeClosed;
 import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.internal.OtelEncodingUtils;
 import io.opentelemetry.sdk.resources.Resource;
-import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
+import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.Optional;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 import java.util.stream.Stream;
 
-/** Factory for {@link Resource} retrieving Container ID information. */
+/**
+ * Factory for {@link Resource} retrieving Container ID information. It supports both cgroup v1 and
+ * v2 runtimes.
+ */
 public final class ContainerResource {
 
-  private static final Logger logger = Logger.getLogger(ContainerResource.class.getName());
-  private static final String UNIQUE_HOST_NAME_FILE_NAME = "/proc/self/cgroup";
-  private static final Resource INSTANCE = buildSingleton(UNIQUE_HOST_NAME_FILE_NAME);
+  static final Filesystem FILESYSTEM_INSTANCE = new Filesystem();
+  private static final Resource INSTANCE = buildSingleton();
 
-  private static Resource buildSingleton(String uniqueHostNameFileName) {
+  private static Resource buildSingleton() {
     // can't initialize this statically without running afoul of animalSniffer on paths
-    return buildResource(Paths.get(uniqueHostNameFileName));
+    return new ContainerResource().buildResource();
   }
 
-  // package private for testing
-  static Resource buildResource(Path path) {
-    return extractContainerId(path)
-        .map(
-            containerId ->
-                Resource.create(Attributes.of(ResourceAttributes.CONTAINER_ID, containerId)))
-        .orElseGet(Resource::empty);
+  private final CgroupV1ContainerIdExtractor v1Extractor;
+  private final CgroupV2ContainerIdExtractor v2Extractor;
+
+  private ContainerResource() {
+    this(new CgroupV1ContainerIdExtractor(), new CgroupV2ContainerIdExtractor());
   }
 
-  /** Returns resource with container information. */
-  public static Resource get() {
-    return INSTANCE;
+  // Visible for testing
+  ContainerResource(
+      CgroupV1ContainerIdExtractor v1Extractor, CgroupV2ContainerIdExtractor v2Extractor) {
+    this.v1Extractor = v1Extractor;
+    this.v2Extractor = v2Extractor;
   }
 
-  /**
-   * 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)
-   *
-   * @return containerId
-   */
-  private static Optional<String> extractContainerId(Path cgroupFilePath) {
-    if (!Files.exists(cgroupFilePath) || !Files.isReadable(cgroupFilePath)) {
-      return Optional.empty();
-    }
-    try (Stream<String> lines = Files.lines(cgroupFilePath)) {
-      return lines
-          .filter(line -> !line.isEmpty())
-          .map(ContainerResource::getIdFromLine)
-          .filter(Optional::isPresent)
-          .findFirst()
-          .orElse(Optional.empty());
-    } catch (Exception e) {
-      logger.log(Level.WARNING, "Unable to read file", e);
-    }
-    return Optional.empty();
+  // Visible for testing
+  Resource buildResource() {
+    return getContainerId()
+        .map(id -> Resource.create(Attributes.of(CONTAINER_ID, id)))
+        .orElseGet(Resource::empty);
   }
 
-  private static Optional<String> getIdFromLine(String line) {
-    // This cgroup output line should have the container id in it
-    int lastSlashIdx = line.lastIndexOf('/');
-    if (lastSlashIdx < 0) {
-      return Optional.empty();
+  private Optional<String> getContainerId() {
+    Optional<String> v1Result = v1Extractor.extractContainerId();
+    if (v1Result.isPresent()) {
+      return v1Result;
     }
+    return v2Extractor.extractContainerId();
+  }
 
-    String containerId;
-
-    String lastSection = line.substring(lastSlashIdx + 1);
-    int colonIdx = lastSection.lastIndexOf(':');
-
-    if (colonIdx != -1) {
-      // since containerd v1.5.0+, containerId is divided by the last colon when the cgroupDriver is
-      // systemd:
-      // https://github.com/containerd/containerd/blob/release/1.5/pkg/cri/server/helpers_linux.go#L64
-      containerId = lastSection.substring(colonIdx + 1);
-    } else {
-      int startIdx = lastSection.lastIndexOf('-');
-      int endIdx = lastSection.lastIndexOf('.');
+  /** Returns resource with container information. */
+  public static Resource get() {
+    return INSTANCE;
+  }
 
-      startIdx = startIdx == -1 ? 0 : startIdx + 1;
-      if (endIdx == -1) {
-        endIdx = lastSection.length();
-      }
-      if (startIdx > endIdx) {
-        return Optional.empty();
-      }
+  // Exists for testing
+  static class Filesystem {
 
-      containerId = lastSection.substring(startIdx, endIdx);
+    boolean isReadable(Path path) {
+      return Files.isReadable(path);
     }
 
-    if (OtelEncodingUtils.isValidBase16String(containerId) && !containerId.isEmpty()) {
-      return Optional.of(containerId);
-    } else {
-      return Optional.empty();
+    @MustBeClosed
+    Stream<String> lines(Path path) throws IOException {
+      return Files.lines(path);
     }
   }
-
-  private ContainerResource() {}
 }
diff --git a/...est/java/io/opentelemetry/instrumentation/resources/CgroupV1ContainerIdExtractorTest.java b/...est/java/io/opentelemetry/instrumentation/resources/CgroupV1ContainerIdExtractorTest.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.resources;
+
+import static io.opentelemetry.instrumentation.resources.CgroupV1ContainerIdExtractor.V1_CGROUP_PATH;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.params.provider.Arguments.arguments;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.util.Optional;
+import java.util.stream.Stream;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class CgroupV1ContainerIdExtractorTest {
+
+  @Mock ContainerResource.Filesystem filesystem;
+
+  @Test
+  void fileNotReadable() throws IOException {
+    when(filesystem.isReadable(V1_CGROUP_PATH)).thenReturn(false);
+    CgroupV1ContainerIdExtractor extractor = new CgroupV1ContainerIdExtractor(filesystem);
+    Optional<String> result = extractor.extractContainerId();
+    assertThat(result).isEmpty();
+    verify(filesystem, never()).lines(any());
+  }
+
+  @ParameterizedTest
+  @ValueSource(
+      strings = {
+        // invalid containerId (non-hex)
+        "13:name=systemd:/podruntime/docker/kubepods/ac679f8a8319c8cf7d38e1adf263bc08d23zzzz",
+        // unrecognized format (last "-" is after last ".")
+        "13:name=systemd:/podruntime/docker/kubepods/ac679f8.a8319c8cf7d38e1adf263bc08-d23zzzz"
+      })
+  void invalidContainerIds(String line) throws IOException {
+    when(filesystem.isReadable(V1_CGROUP_PATH)).thenReturn(true);
+    when(filesystem.lines(V1_CGROUP_PATH)).thenReturn(Stream.of(line));
+
+    CgroupV1ContainerIdExtractor extractor = new CgroupV1ContainerIdExtractor(filesystem);
+    Optional<String> result = extractor.extractContainerId();
+    assertThat(result).isEmpty();
+  }
+
+  @ParameterizedTest
+  @MethodSource("validLines")
+  void validCgroupLines(String line, String expectedContainerId) throws IOException {
+    when(filesystem.isReadable(V1_CGROUP_PATH)).thenReturn(true);
+    when(filesystem.lines(V1_CGROUP_PATH)).thenReturn(Stream.of(line));
+
+    CgroupV1ContainerIdExtractor extractor = new CgroupV1ContainerIdExtractor(filesystem);
+    Optional<String> result = extractor.extractContainerId();
+    assertThat(result.orElse("fail")).isEqualTo(expectedContainerId);
+  }
+
+  static Stream<Arguments> validLines() {
+    return Stream.of(
+        // with suffix
+        arguments(
+            "13:name=systemd:/podruntime/docker/kubepods/ac679f8a8319c8cf7d38e1adf263bc08d23.aaaa",
+            "ac679f8a8319c8cf7d38e1adf263bc08d23"),
+        // with prefix and suffix
+        arguments(
+            "13:name=systemd:/podruntime/docker/kubepods/crio-dc679f8a8319c8cf7d38e1adf263bc08d23.stuff",
+            "dc679f8a8319c8cf7d38e1adf263bc08d23"),
+        // just container id
+        arguments(
+            "13:name=systemd:/pod/d86d75589bf6cc254f3e2cc29debdf85dde404998aa128997a819ff991827356",
+            "d86d75589bf6cc254f3e2cc29debdf85dde404998aa128997a819ff991827356"),
+        // with prefix
+        arguments(
+            "//\n"
+                + "1:name=systemd:/podruntime/docker/kubepods/docker-dc579f8a8319c8cf7d38e1adf263bc08d23"
+                + "2:name=systemd:/podruntime/docker/kubepods/docker-dc579f8a8319c8cf7d38e1adf263bc08d23"
+                + "3:name=systemd:/podruntime/docker/kubepods/docker-dc579f8a8319c8cf7d38e1adf263bc08d23",
+            "dc579f8a8319c8cf7d38e1adf263bc08d23"),
+        // with two dashes in prefix
+        arguments(
+            "11:perf_event:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod4415fd05_2c0f_4533_909b_f2180dca8d7c.slice/cri-containerd-713a77a26fe2a38ebebd5709604a048c3d380db1eb16aa43aca0b2499e54733c.scope",
+            "713a77a26fe2a38ebebd5709604a048c3d380db1eb16aa43aca0b2499e54733c"),
+        // with colon, env: k8s v1.24.0, the cgroupDriver by systemd(default), and container is
+        // cri-containerd v1.6.8
+        arguments(
+            "11:devices:/system.slice/containerd.service/kubepods-pod87a18a64_b74a_454a_b10b_a4a36059d0a3.slice:cri-containerd:05c48c82caff3be3d7f1e896981dd410e81487538936914f32b624d168de9db0",
+            "05c48c82caff3be3d7f1e896981dd410e81487538936914f32b624d168de9db0"));
+  }
+}
diff --git a/...est/java/io/opentelemetry/instrumentation/resources/CgroupV2ContainerIdExtractorTest.java b/...est/java/io/opentelemetry/instrumentation/resources/CgroupV2ContainerIdExtractorTest.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.resources;
+
+import static io.opentelemetry.instrumentation.resources.CgroupV2ContainerIdExtractor.V2_CGROUP_PATH;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
+
+import java.util.Optional;
+import java.util.stream.Stream;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class CgroupV2ContainerIdExtractorTest {
+
+  @Mock ContainerResource.Filesystem filesystem;
+
+  @Test
+  void fileNotReadable() {
+    when(filesystem.isReadable(V2_CGROUP_PATH)).thenReturn(false);
+    CgroupV2ContainerIdExtractor extractor = new CgroupV2ContainerIdExtractor(filesystem);
+    Optional<String> result = extractor.extractContainerId();
+    assertThat(result).isSameAs(Optional.empty());
+  }
+
+  @Test
+  void extractSuccess() throws Exception {
+    when(filesystem.isReadable(V2_CGROUP_PATH)).thenReturn(true);
+    Stream<String> fileContent = getTestFileContent();
+    when(filesystem.lines(V2_CGROUP_PATH)).thenReturn(fileContent);
+    CgroupV2ContainerIdExtractor extractor = new CgroupV2ContainerIdExtractor(filesystem);
+    Optional<String> result = extractor.extractContainerId();
+    assertThat(result.orElse("fail"))
+        .isEqualTo("dc64b5743252dbaef6e30521c34d6bbd1620c8ce65bdb7bf9e7143b61bb5b183");
+  }
+
+  private static Stream<String> getTestFileContent() {
+    return Stream.of(
+        "456 375 0:143 / / rw,relatime master:175 - overlay overlay rw,lowerdir=/var/lib/docker/overlay2/l/37L57D2IM7MEWLVE2Q2ECNDT67:/var/lib/docker/overlay2/l/46FCA2JFPCSNFGAR5TSYLLNHLK,upperdir=/var/lib/docker/overlay2/4e82c300793d703c19bdf887bfdad8b0354edda884ea27a8a2df89ab292719a4/diff,workdir=/var/lib/docker/overlay2/4e82c300793d703c19bdf887bfdad8b0354edda884ea27a8a2df89ab292719a4/work",
+        "457 456 0:146 / /proc rw,nosuid,nodev,noexec,relatime - proc proc rw",
+        "466 456 0:147 / /dev rw,nosuid - tmpfs tmpfs rw,size=65536k,mode=755",
+        "467 466 0:148 / /dev/pts rw,nosuid,noexec,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=666",
+        "468 456 0:149 / /sys ro,nosuid,nodev,noexec,relatime - sysfs sysfs ro",
+        "469 468 0:30 / /sys/fs/cgroup ro,nosuid,nodev,noexec,relatime - cgroup2 cgroup rw",
+        "470 466 0:145 / /dev/mqueue rw,nosuid,nodev,noexec,relatime - mqueue mqueue rw",
+        "471 466 0:150 / /dev/shm rw,nosuid,nodev,noexec,relatime - tmpfs shm rw,size=65536k",
+        "472 456 254:1 /docker/containers/dc64b5743252dbaef6e30521c34d6bbd1620c8ce65bdb7bf9e7143b61bb5b183/resolv.conf /etc/resolv.conf rw,relatime - ext4 /dev/vda1 rw",
+        "473 456 254:1 /docker/containers/dc64b5743252dbaef6e30521c34d6bbd1620c8ce65bdb7bf9e7143b61bb5b183/hostname /etc/hostname rw,relatime - ext4 /dev/vda1 rw",
+        "474 456 254:1 /docker/containers/dc64b5743252dbaef6e30521c34d6bbd1620c8ce65bdb7bf9e7143b61bb5b183/hosts /etc/hosts rw,relatime - ext4 /dev/vda1 rw",
+        "376 466 0:148 /0 /dev/console rw,nosuid,noexec,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=666",
+        "377 457 0:146 /bus /proc/bus ro,nosuid,nodev,noexec,relatime - proc proc rw",
+        "378 457 0:146 /fs /proc/fs ro,nosuid,nodev,noexec,relatime - proc proc rw",
+        "379 457 0:146 /irq /proc/irq ro,nosuid,nodev,noexec,relatime - proc proc rw",
+        "380 457 0:146 /sys /proc/sys ro,nosuid,nodev,noexec,relatime - proc proc rw",
+        "381 457 0:146 /sysrq-trigger /proc/sysrq-trigger ro,nosuid,nodev,noexec,relatime - proc proc rw",
+        "382 457 0:151 / /proc/acpi ro,relatime - tmpfs tmpfs ro",
+        "383 457 0:147 /null /proc/kcore rw,nosuid - tmpfs tmpfs rw,size=65536k,mode=755",
+        "384 457 0:147 /null /proc/keys rw,nosuid - tmpfs tmpfs rw,size=65536k,mode=755",
+        "385 457 0:147 /null /proc/timer_list rw,nosuid - tmpfs tmpfs rw,size=65536k,mode=755",
+        "386 468 0:152 / /sys/firmware ro,relatime - tmpfs tmpfs ");
+  }
+}
diff --git a/...brary/src/test/java/io/opentelemetry/instrumentation/resources/ContainerResourceTest.java b/...brary/src/test/java/io/opentelemetry/instrumentation/resources/ContainerResourceTest.java
@@ -5,91 +5,49 @@
 
 package io.opentelemetry.instrumentation.resources;
 
-import static io.opentelemetry.instrumentation.resources.ContainerResource.buildResource;
+import static io.opentelemetry.semconv.resource.attributes.ResourceAttributes.CONTAINER_ID;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.params.provider.Arguments.arguments;
+import static org.mockito.Mockito.verifyNoInteractions;
+import static org.mockito.Mockito.when;
 
 import io.opentelemetry.sdk.resources.Resource;
-import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.stream.Stream;
+import java.util.Optional;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.io.TempDir;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
-import org.junit.jupiter.params.provider.ValueSource;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
 
+@ExtendWith(MockitoExtension.class)
 class ContainerResourceTest {
 
-  @ParameterizedTest
-  @ValueSource(
-      strings = {
-        // invalid containerId (non-hex)
-        "13:name=systemd:/podruntime/docker/kubepods/ac679f8a8319c8cf7d38e1adf263bc08d23zzzz",
-        // unrecognized format (last "-" is after last ".")
-        "13:name=systemd:/podruntime/docker/kubepods/ac679f8.a8319c8cf7d38e1adf263bc08-d23zzzz"
-      })
-  void buildResource_returnsEmptyResource_whenContainerIdIsInvalid(
-      String line, @TempDir Path tempFolder) throws IOException {
-    Path cgroup = createCgroup(tempFolder.resolve("cgroup"), line);
-    assertThat(buildResource(cgroup)).isEqualTo(Resource.empty());
-  }
+  public static final String TEST_CONTAINER_ID = "abcdef123123deadbeef";
+  @Mock CgroupV1ContainerIdExtractor v1;
+  @Mock CgroupV2ContainerIdExtractor v2;
 
   @Test
-  void buildResource_returnsEmptyResource_whenFileDoesNotExist(@TempDir Path tempFolder) {
-    Path cgroup = tempFolder.resolve("DoesNotExist");
-    assertThat(buildResource(cgroup)).isEqualTo(Resource.empty());
-  }
-
-  @ParameterizedTest
-  @MethodSource("validLines")
-  void buildResource_extractsContainerIdFromValidLines(
-      String line, String expectedContainerId, @TempDir Path tempFolder) throws IOException {
-    Path cgroup = createCgroup(tempFolder.resolve("cgroup"), line);
-    assertThat(getContainerId(buildResource(cgroup))).isEqualTo(expectedContainerId);
+  void v1Success() {
+    when(v1.extractContainerId()).thenReturn(Optional.of(TEST_CONTAINER_ID));
+    ContainerResource containerResource = new ContainerResource(v1, v2);
+    Resource resource = containerResource.buildResource();
+    assertThat(resource.getAttribute(CONTAINER_ID)).isEqualTo(TEST_CONTAINER_ID);
+    verifyNoInteractions(v2);
   }
 
-  static Stream<Arguments> validLines() {
-    return Stream.of(
-        // with suffix
-        arguments(
-            "13:name=systemd:/podruntime/docker/kubepods/ac679f8a8319c8cf7d38e1adf263bc08d23.aaaa",
-            "ac679f8a8319c8cf7d38e1adf263bc08d23"),
-        // with prefix and suffix
-        arguments(
-            "13:name=systemd:/podruntime/docker/kubepods/crio-dc679f8a8319c8cf7d38e1adf263bc08d23.stuff",
-            "dc679f8a8319c8cf7d38e1adf263bc08d23"),
-        // just container id
-        arguments(
-            "13:name=systemd:/pod/d86d75589bf6cc254f3e2cc29debdf85dde404998aa128997a819ff991827356",
-            "d86d75589bf6cc254f3e2cc29debdf85dde404998aa128997a819ff991827356"),
-        // with prefix
-        arguments(
-            "//\n"
-                + "1:name=systemd:/podruntime/docker/kubepods/docker-dc579f8a8319c8cf7d38e1adf263bc08d23"
-                + "2:name=systemd:/podruntime/docker/kubepods/docker-dc579f8a8319c8cf7d38e1adf263bc08d23"
-                + "3:name=systemd:/podruntime/docker/kubepods/docker-dc579f8a8319c8cf7d38e1adf263bc08d23",
-            "dc579f8a8319c8cf7d38e1adf263bc08d23"),
-        // with two dashes in prefix
-        arguments(
-            "11:perf_event:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod4415fd05_2c0f_4533_909b_f2180dca8d7c.slice/cri-containerd-713a77a26fe2a38ebebd5709604a048c3d380db1eb16aa43aca0b2499e54733c.scope",
-            "713a77a26fe2a38ebebd5709604a048c3d380db1eb16aa43aca0b2499e54733c"),
-        // with colon, env: k8s v1.24.0, the cgroupDriver by systemd(default), and container is
-        // cri-containerd v1.6.8
-        arguments(
-            "11:devices:/system.slice/containerd.service/kubepods-pod87a18a64_b74a_454a_b10b_a4a36059d0a3.slice:cri-containerd:05c48c82caff3be3d7f1e896981dd410e81487538936914f32b624d168de9db0",
-            "05c48c82caff3be3d7f1e896981dd410e81487538936914f32b624d168de9db0"));
-  }
-
-  private static String getContainerId(Resource resource) {
-    return resource.getAttribute(ResourceAttributes.CONTAINER_ID);
+  @Test
+  void v2Success() {
+    when(v1.extractContainerId()).thenReturn(Optional.empty());
+    when(v2.extractContainerId()).thenReturn(Optional.of(TEST_CONTAINER_ID));
+    ContainerResource containerResource = new ContainerResource(v1, v2);
+    Resource resource = containerResource.buildResource();
+    assertThat(resource.getAttribute(CONTAINER_ID)).isEqualTo(TEST_CONTAINER_ID);
   }
 
-  private static Path createCgroup(Path path, String line) throws IOException {
-    return Files.write(path, line.getBytes(StandardCharsets.UTF_8));
+  @Test
+  void bothVersionsFail() {
+    when(v1.extractContainerId()).thenReturn(Optional.empty());
+    when(v2.extractContainerId()).thenReturn(Optional.empty());
+    ContainerResource containerResource = new ContainerResource(v1, v2);
+    Resource resource = containerResource.buildResource();
+    assertThat(resource).isSameAs(Resource.empty());
   }
 }