Add cgroupv2 support and fix profile upload response body reading (#4592)

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