Add BaggageRestrictionManager (#217)

jaeger-core/src/main/java/com/uber/jaeger/Span.java

@@ -22,6 +22,7 @@
 
 package com.uber.jaeger;
 
+import com.uber.jaeger.baggage.BaggageSetter;
 import io.opentracing.tag.Tags;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -116,22 +117,13 @@ public List<LogData> getLogs() {
 
   @Override
   public Span setBaggageItem(String key, String value) {
+    if (key == null || value == null) {
+      return this;
+    }
     synchronized (this) {
-      // TODO emit a metric whenever baggage is updated
-      String prevItem = this.getBaggageItem(key);
-      this.context = this.context.withBaggageItem(key, value);
-      if (context.isSampled()) {
-        Map<String, String> fields = new HashMap<String, String>();
-        fields.put("event", "baggage");
-        fields.put("key", key);
-        fields.put("value", value);
-        if (prevItem != null) {
-          fields.put("override", "true");
-        }
-        return this.log(fields);
-      }
+      context = tracer.setBaggage(this, key, value);
+      return this;
     }
-    return this;
   }
 
   @Override

jaeger-core/src/main/java/com/uber/jaeger/Tracer.java

@@ -22,7 +22,9 @@
 
 package com.uber.jaeger;
 
-import com.uber.jaeger.Constants;
+import com.uber.jaeger.baggage.BaggageRestrictionManager;
+import com.uber.jaeger.baggage.BaggageSetter;
+import com.uber.jaeger.baggage.DefaultBaggageRestrictionManager;
 import com.uber.jaeger.exceptions.UnsupportedFormatException;
 import com.uber.jaeger.metrics.Metrics;
 import com.uber.jaeger.metrics.NullStatsReporter;
@@ -74,6 +76,7 @@ public class Tracer implements io.opentracing.Tracer {
   private final Map<String, ?> tags;
   private final boolean zipkinSharedRpcSpan;
   private final ActiveSpanSource activeSpanSource;
+  private final BaggageSetter baggageSetter;
 
   private Tracer(
       String serviceName,
@@ -84,7 +87,8 @@ private Tracer(
       Metrics metrics,
       Map<String, Object> tags,
       boolean zipkinSharedRpcSpan,
-      ActiveSpanSource activeSpanSource) {
+      ActiveSpanSource activeSpanSource,
+      BaggageRestrictionManager baggageRestrictionManager) {
     this.serviceName = serviceName;
     this.reporter = reporter;
     this.sampler = sampler;
@@ -93,6 +97,7 @@ private Tracer(
     this.metrics = metrics;
     this.zipkinSharedRpcSpan = zipkinSharedRpcSpan;
     this.activeSpanSource = activeSpanSource;
+    this.baggageSetter = new BaggageSetter(baggageRestrictionManager, metrics);
 
     this.version = loadVersion();
 
@@ -442,12 +447,13 @@ public static final class Builder {
     private final Sampler sampler;
     private final Reporter reporter;
     private final PropagationRegistry registry = new PropagationRegistry();
-    private Metrics metrics;
+    private Metrics metrics = new Metrics(new StatsFactoryImpl(new NullStatsReporter()));
     private String serviceName;
     private Clock clock = new SystemClock();
     private Map<String, Object> tags = new HashMap<String, Object>();
     private boolean zipkinSharedRpcSpan;
     private ActiveSpanSource activeSpanSource = new ThreadLocalActiveSpanSource();
+    private BaggageRestrictionManager baggageRestrictionManager = new DefaultBaggageRestrictionManager();
 
     public Builder(String serviceName, Reporter reporter, Sampler sampler) {
       if (serviceName == null || serviceName.trim().length() == 0) {
@@ -456,7 +462,6 @@ public Builder(String serviceName, Reporter reporter, Sampler sampler) {
       this.serviceName = serviceName;
       this.reporter = reporter;
       this.sampler = sampler;
-      this.metrics = new Metrics(new StatsFactoryImpl(new NullStatsReporter()));
 
       TextMapCodec textMapCodec = new TextMapCodec(false);
       this.registerInjector(Format.Builtin.TEXT_MAP, textMapCodec);
@@ -524,9 +529,14 @@ public Builder withTags(Map<String, String> tags) {
       return this;
     }
 
+    public Builder withBaggageRestrictionManager(BaggageRestrictionManager baggageRestrictionManager) {
+      this.baggageRestrictionManager = baggageRestrictionManager;
+      return this;
+    }
+
     public Tracer build() {
       return new Tracer(this.serviceName, reporter, sampler, registry, clock, metrics, tags,
-          zipkinSharedRpcSpan, activeSpanSource);
+          zipkinSharedRpcSpan, activeSpanSource, baggageRestrictionManager);
     }
   }
 
@@ -582,4 +592,7 @@ String getHostName() {
     }
   }
 
+  SpanContext setBaggage(Span span, String key, String value) {
+    return baggageSetter.setBaggage(span, key, value);
+  }
 }

jaeger-core/src/main/java/com/uber/jaeger/baggage/BaggageRestrictionManager.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2017, Uber Technologies, Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.uber.jaeger.baggage;
+
+/**
+ * BaggageRestrictionManager is an interface for a class that manages baggage
+ * restrictions for baggage keys. The manager will return a {@link Restriction}
+ * for a specific baggage key which will determine whether the baggage key is
+ * allowed for the current service and any other applicable restrictions on the
+ * baggage value.
+ */
+public interface BaggageRestrictionManager {
+  int DEFAULT_MAX_VALUE_LENGTH = 2048;
+
+  Restriction getRestriction(String service, String key);
+}

jaeger-core/src/main/java/com/uber/jaeger/baggage/BaggageSetter.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2017, Uber Technologies, Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.uber.jaeger.baggage;
+
+import com.uber.jaeger.Span;
+import com.uber.jaeger.SpanContext;
+import com.uber.jaeger.metrics.Metric;
+import com.uber.jaeger.metrics.Metrics;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * BaggageSetter is a class that sets baggage and the logs associated
+ * with the baggage on a given {@link Span}.
+ */
+public class BaggageSetter {
+
+  private final BaggageRestrictionManager restrictionManager;
+  private final Metrics metrics;
+
+  public BaggageSetter(BaggageRestrictionManager restrictionManager, Metrics metrics) {
+    this.restrictionManager = restrictionManager;
+    this.metrics = metrics;
+  }
+
+  /**
+   * Sets the baggage key:value on the {@link Span} and the corresponding
+   * logs. Whether the baggage is set on the span depends on if the key
+   * is allowed to be set by this service.
+   * <p>
+   * A {@link SpanContext} is returned with the new baggage key:value set
+   * if key is valid, else returns the existing {@link SpanContext}
+   * on the {@link Span}.
+   *
+   * @param  span  the span to set the baggage on
+   * @param  value the baggage value to set
+   * @return       the SpanContext with the baggage set
+   */
+  public SpanContext setBaggage(Span span, String key, String value) {
+    Restriction restriction = restrictionManager.getRestriction(span.getTracer().getServiceName(), key);
+    boolean truncated = false;
+    String prevItem = null;
+    if (!restriction.isKeyAllowed()) {
+      metrics.baggageUpdateFailure.inc(1);
+      logFields(span, key, value, prevItem, truncated, restriction.isKeyAllowed());
+      return span.context();
+    }
+    if (value.length() > restriction.getMaxValueLength()) {
+      truncated = true;
+      value = value.substring(0, restriction.getMaxValueLength());
+      metrics.baggageTruncate.inc(1);
+    }
+    prevItem = span.getBaggageItem(key);
+    logFields(span, key, value, prevItem, truncated, restriction.isKeyAllowed());
+    metrics.baggageUpdateSuccess.inc(1);
+    return span.context().withBaggageItem(key, value);
+  }
+
+  private void logFields(Span span, String key, String value, String prevItem, boolean truncated, boolean valid) {
+    if (!span.context().isSampled()) {
+      return;
+    }
+    Map<String, String> fields = new HashMap<String, String>();
+    fields.put("event", "baggage");
+    fields.put("key", key);
+    fields.put("value", value);
+    if (prevItem != null) {
+      fields.put("override", "true");
+    }
+    if (truncated) {
+      fields.put("truncated", "true");
+    }
+    if (!valid) {
+      fields.put("invalid", "true");
+    }
+    span.log(fields);
+  }
+}

jaeger-core/src/main/java/com/uber/jaeger/baggage/DefaultBaggageRestrictionManager.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2017, Uber Technologies, Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.uber.jaeger.baggage;
+
+/**
+ * DefaultBaggageRestrictionManager is a manager that returns a {@link Restriction}
+ * that allows all baggage.
+ */
+public class DefaultBaggageRestrictionManager implements BaggageRestrictionManager {
+  private final Restriction restriction;
+
+  public DefaultBaggageRestrictionManager() {
+    this(DEFAULT_MAX_VALUE_LENGTH);
+  }
+
+  DefaultBaggageRestrictionManager(int maxValueLength) {
+    this.restriction = Restriction.of(true, maxValueLength);
+  }
+
+  @Override
+  public Restriction getRestriction(String service, String key) {
+    return restriction;
+  }
+}

jaeger-core/src/main/java/com/uber/jaeger/baggage/Restriction.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2017, Uber Technologies, Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.uber.jaeger.baggage;
+
+import lombok.Value;
+
+/**
+ * Restriction determines whether a baggage key is allowed and contains any
+ * restrictions on the baggage value.
+ */
+@Value(staticConstructor = "of")
+public class Restriction {
+  boolean keyAllowed;
+  int maxValueLength;
+}

jaeger-core/src/main/java/com/uber/jaeger/metrics/Metrics.java

@@ -211,4 +211,22 @@ public static Metrics fromStatsReporter(StatsReporter reporter) {
   )
   // Number of times the Sampler failed to parse retrieved sampling strategy
   public Counter samplerParsingFailure;
+
+  @Metric(
+      name = "baggage-update",
+      tags = {@Tag(key = "result", value = "ok")}
+  )
+  // Number of times baggage was successfully written or updated on spans
+  public Counter baggageUpdateSuccess;
+
+  @Metric(
+      name = "baggage-update",
+      tags = {@Tag(key = "result", value = "err")}
+  )
+  // Number of times baggage failed to write or update on spans
+  public Counter baggageUpdateFailure;
+
+  @Metric(name = "baggage-truncate")
+  // Number of times baggage was truncated as per baggage restrictions
+  public Counter baggageTruncate;
 }