Add cgroupv2 support.

Add support for modifying where cgroups is mounted to.
Fix bug with reading of the body of profile upload responses, early closing of the response prevented the body from being read

Author: johnoliver

agent/agent-profiler/agent-diagnostics-api/src/main/java/com/microsoft/applicationinsights/diagnostics/DiagnosticEngineFactory.java

@@ -4,12 +4,14 @@
 package com.microsoft.applicationinsights.diagnostics;
 
 import java.util.concurrent.ScheduledExecutorService;
+import javax.annotation.Nullable;
 
 /**
  * Factory to be invoked to create a DiagnosticEngine. This factory will be service loaded by the
  * agent and invoked. It is up to the provider of a DiagnosticEngine to provide a service loader for
  * this interface.
  */
 public interface DiagnosticEngineFactory {
-  DiagnosticEngine create(ScheduledExecutorService executorService);
+  DiagnosticEngine create(
+      ScheduledExecutorService executorService, @Nullable String cgroupBasePath);
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/appinsights/CodeOptimizerApplicationInsightFactoryJfr.java

@@ -6,13 +6,58 @@
 import com.google.auto.service.AutoService;
 import com.microsoft.applicationinsights.diagnostics.DiagnosticEngine;
 import com.microsoft.applicationinsights.diagnostics.DiagnosticEngineFactory;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.concurrent.ScheduledExecutorService;
+import javax.annotation.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /** Factory for Code Optimizer diagnostics to be service loaded */
 @AutoService(DiagnosticEngineFactory.class)
 public class CodeOptimizerApplicationInsightFactoryJfr implements DiagnosticEngineFactory {
+
+  private static final Path FILE_SYSTEM_ROOT =
+      Paths.get(System.getProperty("applicationinsights.profiler.filesystemRoot", "/"));
+  private static final Path CGROUP_DIR = Paths.get("./sys/fs/cgroup");
+
+  private static final Logger logger =
+      LoggerFactory.getLogger(CodeOptimizerApplicationInsightFactoryJfr.class);
+
   @Override
-  public DiagnosticEngine create(ScheduledExecutorService executorService) {
-    return new CodeOptimizerDiagnosticEngineJfr(executorService);
+  public DiagnosticEngine create(
+      ScheduledExecutorService executorService, @Nullable String cgroupBasePath) {
+    Path cgroupPath = getCgroupPath(cgroupBasePath);
+    return new CodeOptimizerDiagnosticEngineJfr(executorService, cgroupPath);
+  }
+
+  @SuppressFBWarnings(
+      value = "SECPTI", // Potential Path Traversal
+      justification =
+          "The constructed file path cannot be controlled by an end user of the instrumented application")
+  @Nullable
+  private static Path getCgroupPath(@Nullable String cgroupBasePath) {
+    Path cgroupPath = null;
+    if (cgroupBasePath != null) {
+      cgroupPath = Paths.get(cgroupBasePath);
+
+      if (!Files.exists(cgroupPath)) {
+        logger.warn("Configured Cgroup path {} does not exist, setting to default", cgroupBasePath);
+        cgroupPath = null;
+      }
+    }
+
+    if (cgroupPath == null) {
+      cgroupPath = FILE_SYSTEM_ROOT.resolve(CGROUP_DIR);
+
+      if (!Files.exists(cgroupPath)) {
+        logger.warn("Expected default Cgroup path {} does not exist", cgroupBasePath);
+        cgroupPath = null;
+      }
+    }
+
+    return cgroupPath;
   }
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/appinsights/CodeOptimizerDiagnosticEngineJfr.java

@@ -14,6 +14,7 @@
 import com.microsoft.applicationinsights.diagnostics.jfr.SystemStatsProvider;
 import java.io.IOException;
 import java.io.StringWriter;
+import java.nio.file.Path;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
@@ -33,10 +34,13 @@ public class CodeOptimizerDiagnosticEngineJfr implements DiagnosticEngine {
   public static final long TIME_BEFORE_END_OF_PROFILE_TO_EMIT_EVENT = 10L;
   private final ScheduledExecutorService executorService;
   private final Semaphore semaphore = new Semaphore(1, false);
+  private final Path cgroupBasePath;
   private int thisPid;
 
-  public CodeOptimizerDiagnosticEngineJfr(ScheduledExecutorService executorService) {
+  public CodeOptimizerDiagnosticEngineJfr(
+      ScheduledExecutorService executorService, Path cgroupBasePath) {
     this.executorService = executorService;
+    this.cgroupBasePath = cgroupBasePath;
   }
 
   @Override
@@ -49,14 +53,14 @@ public void init(int thisPid) {
     this.thisPid = thisPid;
 
     logger.debug("Initialising Code Optimizer Diagnostic Engine");
-    CodeOptimizerDiagnosticsJfrInit.initFeature(thisPid);
+    CodeOptimizerDiagnosticsJfrInit.initFeature(thisPid, cgroupBasePath);
     logger.debug("Code Optimizer Diagnostic Engine Initialised");
   }
 
-  private static void startDiagnosticCycle(int thisPid) {
+  private static void startDiagnosticCycle(int thisPid, Path cgroupBasePath) {
     logger.debug("Starting Code Optimizer Diagnostic Cycle");
-    CodeOptimizerDiagnosticsJfrInit.initFeature(thisPid);
-    CodeOptimizerDiagnosticsJfrInit.start(thisPid);
+    CodeOptimizerDiagnosticsJfrInit.initFeature(thisPid, cgroupBasePath);
+    CodeOptimizerDiagnosticsJfrInit.start(thisPid, cgroupBasePath);
   }
 
   private static void endDiagnosticCycle() {
@@ -70,13 +74,13 @@ public Future<DiagnosisResult<?>> performDiagnosis(AlertBreach alert) {
         new CompletableFuture<>();
     try {
       if (semaphore.tryAcquire(SEMAPHORE_TIMEOUT_IN_SEC, TimeUnit.SECONDS)) {
-        emitInfo(alert);
+        emitInfo(alert, cgroupBasePath);
 
         long profileDurationInSec = alert.getAlertConfiguration().getProfileDurationSeconds();
 
         long end = profileDurationInSec - TIME_BEFORE_END_OF_PROFILE_TO_EMIT_EVENT;
 
-        startDiagnosticCycle(thisPid);
+        startDiagnosticCycle(thisPid, cgroupBasePath);
 
         scheduleEmittingAlertBreachEvent(alert, end);
 
@@ -101,7 +105,7 @@ private void scheduleShutdown(
     executorService.schedule(
         () -> {
           try {
-            emitInfo(alert);
+            emitInfo(alert, cgroupBasePath);
 
             // We do not return a result atm
             diagnosisResultCompletableFuture.complete(null);
@@ -123,7 +127,7 @@ private void scheduleEmittingAlertBreachEvent(AlertBreach alert, long end) {
     executorService.schedule(
         () -> {
           try {
-            emitInfo(alert);
+            emitInfo(alert, cgroupBasePath);
           } catch (RuntimeException e) {
             logger.error("Failed to emit breach", e);
           }
@@ -132,10 +136,10 @@ private void scheduleEmittingAlertBreachEvent(AlertBreach alert, long end) {
         TimeUnit.SECONDS);
   }
 
-  private static void emitInfo(AlertBreach alert) {
+  private static void emitInfo(AlertBreach alert, Path cgroupBasePath) {
     logger.debug("Emitting Code Optimizer Diagnostic Event");
     emitAlertBreachJfrEvent(alert);
-    CodeOptimizerDiagnosticsJfrInit.emitCGroupData();
+    CodeOptimizerDiagnosticsJfrInit.emitCGroupData(cgroupBasePath);
     emitMachineStats();
   }
 

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/kernel/CGroupDataReader.java

@@ -19,4 +19,6 @@ public interface CGroupDataReader {
   long getCpuLimit() throws OperatingSystemInteractionException;
 
   long getCpuPeriod() throws OperatingSystemInteractionException;
+
+  boolean isAvailable();
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/kernel/CGroupUsageDataReader.java

@@ -13,4 +13,6 @@
 public interface CGroupUsageDataReader extends TwoStepUpdatable, Closeable {
   @Nullable
   List<Double> getTelemetry();
+
+  boolean isAvailable();
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/os/linux/cgroups/CGroupCpuSystemReader.java

@@ -3,11 +3,12 @@
 
 package com.microsoft.applicationinsights.diagnostics.collection.libos.os.linux.cgroups;
 
-@SuppressWarnings(
-    "checkstyle:AbbreviationAsWordInName") // CGroup is the standard abbreviation for Control Group
+import java.nio.file.Path;
+
+@SuppressWarnings("checkstyle:AbbreviationAsWordInName")
 public class CGroupCpuSystemReader extends CGroupValueReader {
   // total system CPU time (in nanoseconds) consumed by all tasks in this cgroup
-  public CGroupCpuSystemReader() {
-    super("/sys/fs/cgroup/cpu,cpuacct/cpuacct.usage_sys");
+  public CGroupCpuSystemReader(Path cgroupPath) {
+    super(cgroupPath.resolve("./cpuacct.usage_sys"));
   }
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/os/linux/cgroups/CGroupCpuUsageReader.java

@@ -3,11 +3,12 @@
 
 package com.microsoft.applicationinsights.diagnostics.collection.libos.os.linux.cgroups;
 
-@SuppressWarnings(
-    "checkstyle:AbbreviationAsWordInName") // CGroup is the standard abbreviation for Control Group
+import java.nio.file.Path;
+
+@SuppressWarnings("checkstyle:AbbreviationAsWordInName")
 public class CGroupCpuUsageReader extends CGroupValueReader {
   // total CPU usage (in nanoseconds) consumed by all tasks in this cgroup
-  public CGroupCpuUsageReader() {
-    super("/sys/fs/cgroup/cpu,cpuacct/cpuacct.usage");
+  public CGroupCpuUsageReader(Path cgroupPath) {
+    super(cgroupPath.resolve("./cpuacct.usage"));
   }
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/os/linux/cgroups/CGroupCpuUserReader.java

@@ -3,11 +3,12 @@
 
 package com.microsoft.applicationinsights.diagnostics.collection.libos.os.linux.cgroups;
 
-@SuppressWarnings(
-    "checkstyle:AbbreviationAsWordInName") // CGroup is the standard abbreviation for Control Group
+import java.nio.file.Path;
+
+@SuppressWarnings("checkstyle:AbbreviationAsWordInName")
 public class CGroupCpuUserReader extends CGroupValueReader {
   // total user CPU time (in nanoseconds) consumed by all tasks in this cgroup
-  public CGroupCpuUserReader() {
-    super("/sys/fs/cgroup/cpu,cpuacct/cpuacct.usage_user");
+  public CGroupCpuUserReader(Path cgroupPath) {
+    super(cgroupPath.resolve("./cpuacct.usage_user"));
   }
 }

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/os/linux/cgroups/CGroupStatReader.java

@@ -5,16 +5,15 @@
 
 import com.microsoft.applicationinsights.diagnostics.collection.libos.BigIncrementalCounter;
 import com.microsoft.applicationinsights.diagnostics.collection.libos.os.linux.TwoStepProcReader;
-import java.io.File;
+import java.nio.file.Path;
 
-@SuppressWarnings(
-    "checkstyle:AbbreviationAsWordInName") // CGroup is the standard abbreviation for Control Group
+@SuppressWarnings("checkstyle:AbbreviationAsWordInName")
 public class CGroupStatReader extends TwoStepProcReader {
   private final BigIncrementalCounter user = new BigIncrementalCounter();
   private final BigIncrementalCounter system = new BigIncrementalCounter();
 
-  public CGroupStatReader() {
-    super(new File("/sys/fs/cgroup/cpu,cpuacct/cpuacct.stat"), true);
+  public CGroupStatReader(Path cgroupPath) {
+    super(cgroupPath.resolve("./cpuacct.stat").toFile(), true);
   }
 
   @Override

agent/agent-profiler/agent-diagnostics/src/main/java/com/microsoft/applicationinsights/diagnostics/collection/libos/os/linux/cgroups/CGroupValueReader.java

@@ -5,15 +5,14 @@
 
 import com.microsoft.applicationinsights.diagnostics.collection.libos.BigIncrementalCounter;
 import com.microsoft.applicationinsights.diagnostics.collection.libos.os.linux.TwoStepProcReader;
-import java.io.File;
+import java.nio.file.Path;
 
-@SuppressWarnings(
-    "checkstyle:AbbreviationAsWordInName") // CGroup is the standard abbreviation for Control Group
+@SuppressWarnings("checkstyle:AbbreviationAsWordInName")
 public abstract class CGroupValueReader extends TwoStepProcReader {
   private final BigIncrementalCounter usage = new BigIncrementalCounter();
 
-  public CGroupValueReader(String fileName) {
-    super(new File(fileName), true);
+  public CGroupValueReader(Path file) {
+    super(file.toFile(), true);
   }
 
   @Override