Phase1 jetty linux (#46)

* PoC for setting app server middleware attributes from splunk distro.

* First iteration of jetty test matrix.

* Proper end-to-end test for Jetty.

* Added copyright headers.

* Spotless.

* Temporarily build test images before smoke test.

* Rename shared to bootstrap and other PR fixes.

* Removed middleware submodule.

* Verify middleware attributes also in webapp test.

* spotless

* Add middleware attributes to the server span only.

* Add a TODO reference to an important PR.

agent/build.gradle

@@ -0,0 +1,72 @@
+plugins {
+    id("com.github.johnrengelman.shadow") version "6.0.0"
+}
+configurations {
+    customShadow
+}
+dependencies {
+    customShadow project(path: ":custom", configuration: "shadow")
+    customShadow project(path: ":instrumentation", configuration: "shadow")
+    implementation "io.opentelemetry.javaagent:opentelemetry-javaagent:${versions.opentelemetryJavaagent}:all"
+    implementation project(":bootstrap")
+}
+
+archivesBaseName = "splunk-otel-javaagent"
+
+compileJava {
+    options.release.set(8)
+}
+
+CopySpec isolateSpec() {
+    return copySpec {
+        configurations.customShadow.files.each {
+            from(zipTree(it)) {
+                into("inst")
+                rename("(^.*)\\.class\$", "\$1.classdata")
+            }
+        }
+    }
+}
+
+tasks {
+    shadowJar {
+        dependsOn ':custom:shadowJar'
+        dependsOn ':instrumentation:shadowJar'
+        dependsOn ':bootstrap:jar'
+        with isolateSpec()
+
+        /// TODO - with this set to EXCLUDE, service files will not be merged between instrumentation and custom
+        duplicatesStrategy = DuplicatesStrategy.INCLUDE
+
+        mergeServiceFiles {
+            include("inst/META-INF/services/*")
+        }
+        exclude("**/module-info.class")
+
+        // Prevents conflict with other SLF4J instances. Important for premain.
+        relocate("org.slf4j", "io.opentelemetry.javaagent.slf4j")
+        // rewrite dependencies calling Logger.getLogger
+        relocate("java.util.logging.Logger", "io.opentelemetry.javaagent.bootstrap.PatchLogger")
+
+        // prevents conflict with library instrumentation
+        relocate("io.opentelemetry.instrumentation.api", "io.opentelemetry.javaagent.shaded.instrumentation.api")
+
+        // relocate OpenTelemetry API
+        relocate("io.opentelemetry.api", "io.opentelemetry.javaagent.shaded.io.opentelemetry.api")
+        relocate("io.opentelemetry.context", "io.opentelemetry.javaagent.shaded.io.opentelemetry.context")
+
+        manifest {
+            attributes.put("Main-Class", "io.opentelemetry.javaagent.OpenTelemetryAgent")
+            attributes.put("Agent-Class", "com.splunk.opentelemetry.SplunkAgent")
+            attributes.put("Premain-Class", "com.splunk.opentelemetry.SplunkAgent")
+            attributes.put("Can-Redefine-Classes", "true")
+            attributes.put("Can-Retransform-Classes", "true")
+            attributes.put("Implementation-Vendor", "Splunk")
+            attributes.put("Implementation-Version", "splunk-${project.version}-otel-${versions["opentelemetryJavaagent"]}")
+        }
+    }
+
+    assemble {
+        dependsOn(shadowJar)
+    }
+}

bootstrap/build.gradle

@@ -0,0 +1,11 @@
+plugins {
+    id "java"
+}
+
+compileJava {
+    options.release.set(8)
+}
+
+dependencies {
+    implementation "org.slf4j:slf4j-api:1.7.30"
+}

bootstrap/src/main/java/com/splunk/opentelemetry/javaagent/bootstrap/MiddlewareHolder.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright Splunk Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.splunk.opentelemetry.javaagent.bootstrap;
+
+import java.util.concurrent.atomic.AtomicReference;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MiddlewareHolder {
+
+  private static final Logger log = LoggerFactory.getLogger(MiddlewareHolder.class);
+
+  public static final AtomicReference<String> middlewareName = new AtomicReference<>();
+  public static final AtomicReference<String> middlewareVersion = new AtomicReference<>();
+
+  public static void trySetName(String name) {
+    if (!middlewareName.compareAndSet(null, name)) {
+      log.debug("Trying to re-set middleware name from {} to {}", middlewareName.get(), name);
+    }
+  }
+
+  public static void trySetVersion(String version) {
+    if (!middlewareVersion.compareAndSet(null, version)) {
+      log.debug(
+          "Trying to re-set middleware version from {} to {}", middlewareVersion.get(), version);
+    }
+  }
+}

custom/build.gradle.kts

@@ -6,9 +6,14 @@ plugins {
 val versions: Map<String, String> by extra
 
 dependencies {
+  implementation(project(":bootstrap"))
   implementation("io.opentelemetry:opentelemetry-sdk:${versions["opentelemetry"]}")
   implementation("io.opentelemetry:opentelemetry-exporter-jaeger-thrift:${versions["opentelemetry"]}")
   implementation("io.opentelemetry.javaagent:opentelemetry-javaagent-spi:${versions["opentelemetryJavaagent"]}")
+  annotationProcessor("com.google.auto.service:auto-service:1.0-rc3")
+  annotationProcessor("com.google.auto:auto-common:0.8")
+  implementation("com.google.auto.service:auto-service:1.0-rc3")
+  implementation("com.google.auto:auto-common:0.8")
 }
 
 tasks {

custom/src/main/java/com/splunk/opentelemetry/middleware/MiddlewareAttributeSpanProcessor.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright Splunk Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.splunk.opentelemetry.middleware;
+
+import com.splunk.opentelemetry.javaagent.bootstrap.MiddlewareHolder;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.trace.ReadWriteSpan;
+import io.opentelemetry.sdk.trace.ReadableSpan;
+import io.opentelemetry.sdk.trace.SpanProcessor;
+
+public class MiddlewareAttributeSpanProcessor implements SpanProcessor {
+
+  @Override
+  public void onStart(Context parentContext, ReadWriteSpan span) {
+    String middlewareName = MiddlewareHolder.middlewareName.get();
+    String middlewareVersion = MiddlewareHolder.middlewareVersion.get();
+    // Getting span kind is not the most straightforward or cheap operation apparently.
+    // TODO: Once this PR is merged and released, use span.getKind directly:
+    //    https://github.com/open-telemetry/opentelemetry-java/pull/2162
+    // Let's do quick cheap null checks first and exit quickly.
+    if ((middlewareName == null && middlewareVersion == null)
+        || span.toSpanData().getKind() != Span.Kind.SERVER) {
+      return;
+    }
+    if (middlewareName != null) {
+      span.setAttribute(MiddlewareAttributes.MIDDLEWARE_NAME.key, middlewareName);
+    }
+    if (middlewareVersion != null) {
+      span.setAttribute(MiddlewareAttributes.MIDDLEWARE_VERSION.key, middlewareVersion);
+    }
+  }
+
+  @Override
+  public boolean isStartRequired() {
+    return true;
+  }
+
+  @Override
+  public void onEnd(ReadableSpan span) {}
+
+  @Override
+  public boolean isEndRequired() {
+    return false;
+  }
+
+  @Override
+  public CompletableResultCode shutdown() {
+    return CompletableResultCode.ofSuccess();
+  }
+
+  @Override
+  public CompletableResultCode forceFlush() {
+    return CompletableResultCode.ofSuccess();
+  }
+}

custom/src/main/java/com/splunk/opentelemetry/middleware/MiddlewareAttributes.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright Splunk Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.splunk.opentelemetry.middleware;
+
+public enum MiddlewareAttributes {
+  MIDDLEWARE_NAME("middleware.name"),
+  MIDDLEWARE_VERSION("middleware.version");
+
+  public final String key;
+
+  MiddlewareAttributes(String key) {
+    this.key = key;
+  }
+}

custom/src/main/java/com/splunk/opentelemetry/middleware/MiddlewareBootstrapPackagesProvider.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright Splunk Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.splunk.opentelemetry.middleware;
+
+import com.google.auto.service.AutoService;
+import com.splunk.opentelemetry.javaagent.bootstrap.MiddlewareHolder;
+import io.opentelemetry.javaagent.spi.BootstrapPackagesProvider;
+import java.util.Collections;
+import java.util.List;
+
+@AutoService(BootstrapPackagesProvider.class)
+public class MiddlewareBootstrapPackagesProvider implements BootstrapPackagesProvider {
+
+  @Override
+  public List<String> getPackagePrefixes() {
+    return Collections.singletonList(MiddlewareHolder.class.getPackage().getName());
+  }
+}

custom/src/main/java/com/splunk/opentelemetry/middleware/MiddlewareTracerCustomizer.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright Splunk Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.splunk.opentelemetry.middleware;
+
+import com.google.auto.service.AutoService;
+import io.opentelemetry.javaagent.spi.TracerCustomizer;
+import io.opentelemetry.sdk.trace.TracerSdkManagement;
+
+@AutoService(TracerCustomizer.class)
+public class MiddlewareTracerCustomizer implements TracerCustomizer {
+
+  @Override
+  public void configure(TracerSdkManagement tracerManagement) {
+    tracerManagement.addSpanProcessor(new MiddlewareAttributeSpanProcessor());
+  }
+}