Actually wire entities into resource

- Remove ResourceWithEntity, no way to keep bincompat that way
- Update toString tests to be a lot more forgiving, but preserve intent

Author: jsuereth

docs/apidiffs/current_vs_latest/opentelemetry-sdk-common.txt

@@ -1,2 +1,11 @@
 Comparing source compatibility of opentelemetry-sdk-common-1.52.0-SNAPSHOT.jar against opentelemetry-sdk-common-1.51.0.jar
-No changes.
+**** MODIFIED CLASS: PUBLIC ABSTRACT io.opentelemetry.sdk.resources.Resource  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	+++  NEW METHOD: PUBLIC(+) STATIC(+) io.opentelemetry.sdk.resources.Resource create(io.opentelemetry.api.common.Attributes, java.lang.String, java.util.Collection<io.opentelemetry.sdk.resources.internal.Entity>)
+	***  MODIFIED METHOD: PUBLIC NON_ABSTRACT (<- ABSTRACT) io.opentelemetry.api.common.Attributes getAttributes()
+	+++* NEW METHOD: PUBLIC(+) ABSTRACT(+) java.util.Collection<io.opentelemetry.sdk.resources.internal.Entity> getEntities()
+	+++* NEW METHOD: PUBLIC(+) ABSTRACT(+) io.opentelemetry.api.common.Attributes getRawAttributes()
+***  MODIFIED CLASS: PUBLIC io.opentelemetry.sdk.resources.ResourceBuilder  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	+++  NEW METHOD: PUBLIC(+) io.opentelemetry.sdk.resources.ResourceBuilder add(io.opentelemetry.sdk.resources.internal.Entity)
+	+++  NEW METHOD: PUBLIC(+) io.opentelemetry.sdk.resources.ResourceBuilder addAll(java.util.Collection<io.opentelemetry.sdk.resources.internal.Entity>)

exporters/otlp/common/src/main/java/io/opentelemetry/exporter/internal/otlp/ResourceMarshaler.java

@@ -38,8 +38,9 @@ public static ResourceMarshaler create(io.opentelemetry.sdk.resources.Resource r
       RealResourceMarshaler realMarshaler =
           new RealResourceMarshaler(
               KeyValueMarshaler.createForAttributes(resource.getAttributes()),
-              // TODO(jsuereth): This will support EntityRef in the future.
-              new EntityRefMarshaler[] {});
+              resource.getEntities().stream()
+                  .map(EntityRefMarshaler::createForEntity)
+                  .toArray(MarshalerWithSize[]::new));
 
       ByteArrayOutputStream binaryBos =
           new ByteArrayOutputStream(realMarshaler.getBinarySerializedSize());

sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/DeclarativeConfigurationCreateTest.java

@@ -165,7 +165,7 @@ void create_ModelCustomizer() {
                 DeclarativeConfigurationCreateTest.class.getClassLoader()));
     assertThat(sdk.toString())
         .contains(
-            "resource=Resource{schemaUrl=null, attributes={"
+            "resource=Resource{schemaUrl=null, rawAttributes={"
                 + "color=\"blue\", "
                 + "foo=\"bar\", "
                 + "service.name=\"unknown_service:java\", "

sdk/all/src/test/java/io/opentelemetry/sdk/OpenTelemetrySdkTest.java

@@ -406,34 +406,13 @@ void stringRepresentation() {
             .setPropagators(ContextPropagators.create(propagator))
             .build();
 
+    // Test that toString delegates to underlying classes, and make sure their toString is also
+    // nice.
     assertThat(sdk.toString())
-        .isEqualTo(
-            "OpenTelemetrySdk{"
-                + "tracerProvider=SdkTracerProvider{"
-                + "clock=SystemClock{}, "
-                + "idGenerator=RandomIdGenerator{}, "
-                + "resource=Resource{schemaUrl=null, attributes={service.name=\"otel-test\"}}, "
-                + "spanLimitsSupplier=SpanLimitsValue{maxNumberOfAttributes=128, maxNumberOfEvents=128, maxNumberOfLinks=128, maxNumberOfAttributesPerEvent=128, maxNumberOfAttributesPerLink=128, maxAttributeValueLength=2147483647}, "
-                + "sampler=ParentBased{root:AlwaysOnSampler,remoteParentSampled:AlwaysOnSampler,remoteParentNotSampled:AlwaysOffSampler,localParentSampled:AlwaysOnSampler,localParentNotSampled:AlwaysOffSampler}, "
-                + "spanProcessor=SimpleSpanProcessor{spanExporter=MultiSpanExporter{spanExporters=[MockSpanExporter{}, MockSpanExporter{}]}, exportUnsampledSpans=false}, "
-                + "tracerConfigurator=ScopeConfiguratorImpl{conditions=[]}"
-                + "}, "
-                + "meterProvider=SdkMeterProvider{"
-                + "clock=SystemClock{}, "
-                + "resource=Resource{schemaUrl=null, attributes={service.name=\"otel-test\"}}, "
-                + "metricReaders=[PeriodicMetricReader{exporter=MockMetricExporter{}, intervalNanos=60000000000}], "
-                + "metricProducers=[], "
-                + "views=[RegisteredView{instrumentSelector=InstrumentSelector{instrumentName=instrument}, view=View{name=new-instrument, aggregation=DefaultAggregation, attributesProcessor=NoopAttributesProcessor{}, cardinalityLimit=2000}}], "
-                + "meterConfigurator=ScopeConfiguratorImpl{conditions=[]}"
-                + "}, "
-                + "loggerProvider=SdkLoggerProvider{"
-                + "clock=SystemClock{}, "
-                + "resource=Resource{schemaUrl=null, attributes={service.name=\"otel-test\"}}, "
-                + "logLimits=LogLimits{maxNumberOfAttributes=128, maxAttributeValueLength=2147483647}, "
-                + "logRecordProcessor=SimpleLogRecordProcessor{logRecordExporter=MultiLogRecordExporter{logRecordExporters=[MockLogRecordExporter{}, MockLogRecordExporter{}]}}, "
-                + "loggerConfigurator=ScopeConfiguratorImpl{conditions=[]}"
-                + "}, "
-                + "propagators=DefaultContextPropagators{textMapPropagator=MockTextMapPropagator{}}"
-                + "}");
+        .matches("OpenTelemetrySdk\\{.*}")
+        .matches("OpenTelemetrySdk\\{tracerProvider=SdkTracerProvider\\{.*}.*}")
+        .matches("OpenTelemetrySdk\\{.*, meterProvider=SdkMeterProvider\\{.*}.*}")
+        .matches("OpenTelemetrySdk\\{.*, loggerProvider=SdkLoggerProvider\\{.*}.*}")
+        .matches("OpenTelemetrySdk\\{.*, propagators=DefaultContextPropagators\\{.*}}");
   }
 }

sdk/common/src/main/java/io/opentelemetry/sdk/resources/Resource.java

@@ -11,8 +11,11 @@
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.sdk.common.internal.OtelVersion;
 import io.opentelemetry.sdk.resources.internal.AttributeCheckUtil;
+import io.opentelemetry.sdk.resources.internal.Entity;
+import io.opentelemetry.sdk.resources.internal.EntityUtil;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Objects;
-import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
@@ -23,8 +26,6 @@
 @Immutable
 @AutoValue
 public abstract class Resource {
-  private static final Logger logger = Logger.getLogger(Resource.class.getName());
-
   private static final AttributeKey<String> SERVICE_NAME = AttributeKey.stringKey("service.name");
   private static final AttributeKey<String> TELEMETRY_SDK_LANGUAGE =
       AttributeKey.stringKey("telemetry.sdk.language");
@@ -100,8 +101,24 @@ public static Resource create(Attributes attributes) {
    *     ASCII string or exceed {@link AttributeCheckUtil#MAX_LENGTH} characters.
    */
   public static Resource create(Attributes attributes, @Nullable String schemaUrl) {
+    return create(attributes, schemaUrl, Collections.emptyList());
+  }
+
+  /**
+   * Returns a {@link Resource}.
+   *
+   * @param attributes a map of {@link Attributes} that describe the resource.
+   * @param schemaUrl The URL of the OpenTelemetry schema used to create this Resource.
+   * @param entities The set of detected {@link Entity}s that participate in this resource.
+   * @return a {@code Resource}.
+   * @throws NullPointerException if {@code attributes} is null.
+   * @throws IllegalArgumentException if attribute key or attribute value is not a valid printable
+   *     ASCII string or exceed {@link AttributeCheckUtil#MAX_LENGTH} characters.
+   */
+  public static Resource create(
+      Attributes attributes, @Nullable String schemaUrl, Collection<Entity> entities) {
     AttributeCheckUtil.checkAttributes(Objects.requireNonNull(attributes, "attributes"));
-    return new AutoValue_Resource(schemaUrl, attributes);
+    return new AutoValue_Resource(schemaUrl, attributes, entities);
   }
 
   /**
@@ -113,12 +130,38 @@ public static Resource create(Attributes attributes, @Nullable String schemaUrl)
   @Nullable
   public abstract String getSchemaUrl();
 
+  /**
+   * Returns a map of attributes that describe the resource, not associated with entites.
+   *
+   * @return a map of attributes.
+   */
+  public abstract Attributes getRawAttributes();
+
+  /**
+   * Returns a collectoion of associated entities.
+   *
+   * @return a collection of entities.
+   */
+  public abstract Collection<Entity> getEntities();
+
   /**
    * Returns a map of attributes that describe the resource.
    *
    * @return a map of attributes.
    */
-  public abstract Attributes getAttributes();
+  // @Memoized - This breaks nullaway.
+  public Attributes getAttributes() {
+    AttributesBuilder result = Attributes.builder();
+    getEntities()
+        .forEach(
+            e -> {
+              result.putAll(e.getId());
+              result.putAll(e.getDescription());
+            });
+    // In merge rules, raw comes last, so we return these last.
+    result.putAll(getRawAttributes());
+    return result.build();
+  }
 
   /**
    * Returns the value for a given resource attribute key.
@@ -138,32 +181,7 @@ public <T> T getAttribute(AttributeKey<T> key) {
    * @return the newly merged {@code Resource}.
    */
   public Resource merge(@Nullable Resource other) {
-    if (other == null || other == EMPTY) {
-      return this;
-    }
-
-    AttributesBuilder attrBuilder = Attributes.builder();
-    attrBuilder.putAll(this.getAttributes());
-    attrBuilder.putAll(other.getAttributes());
-
-    if (other.getSchemaUrl() == null) {
-      return create(attrBuilder.build(), getSchemaUrl());
-    }
-    if (getSchemaUrl() == null) {
-      return create(attrBuilder.build(), other.getSchemaUrl());
-    }
-    if (!other.getSchemaUrl().equals(getSchemaUrl())) {
-      logger.info(
-          "Attempting to merge Resources with different schemaUrls. "
-              + "The resulting Resource will have no schemaUrl assigned. Schema 1: "
-              + getSchemaUrl()
-              + " Schema 2: "
-              + other.getSchemaUrl());
-      // currently, behavior is undefined if schema URLs don't match. In the future, we may
-      // apply schema transformations if possible.
-      return create(attrBuilder.build(), null);
-    }
-    return create(attrBuilder.build(), getSchemaUrl());
+    return EntityUtil.merge(this, other);
   }
 
   /**

sdk/common/src/main/java/io/opentelemetry/sdk/resources/ResourceBuilder.java

@@ -8,7 +8,14 @@
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.sdk.resources.internal.Entity;
+import io.opentelemetry.sdk.resources.internal.EntityUtil;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 
 /**
@@ -20,6 +27,7 @@
 public class ResourceBuilder {
 
   private final AttributesBuilder attributesBuilder = Attributes.builder();
+  private final List<Entity> entities = new ArrayList<>();
   @Nullable private String schemaUrl;
 
   /**
@@ -194,6 +202,32 @@ public ResourceBuilder setSchemaUrl(String schemaUrl) {
 
   /** Create the {@link Resource} from this. */
   public Resource build() {
-    return Resource.create(attributesBuilder.build(), schemaUrl);
+    // What checks should we do on "real" resource here?
+    // Derive schemaUrl from entitiy, if able.
+    if (schemaUrl == null) {
+      Set<String> entitySchemas =
+          entities.stream().map(Entity::getSchemaUrl).collect(Collectors.toSet());
+      if (entitySchemas.size() == 1) {
+        // Updated Entities use same schema, we can preserve it.
+        schemaUrl = entitySchemas.iterator().next();
+      }
+    }
+
+    // TODO - here we deal with conflicts between entities and raw attributes.
+    // When adding an entity, we remove any raw attributes it may conflict with.
+    this.attributesBuilder.removeIf(key -> EntityUtil.hasAttributeKey(this.entities, key));
+    return Resource.create(attributesBuilder.build(), schemaUrl, entities);
+  }
+
+  /** Appends a new entity on to the end of the list of entities. */
+  public ResourceBuilder add(Entity e) {
+    this.entities.add(e);
+    return this;
+  }
+
+  /** Appends a new collection of entities on to the end of the list of entities. */
+  public ResourceBuilder addAll(Collection<Entity> entities) {
+    this.entities.addAll(entities);
+    return this;
   }
 }

sdk/common/src/main/java/io/opentelemetry/sdk/resources/internal/EntityUtil.java

@@ -8,6 +8,7 @@
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.sdk.resources.Resource;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -29,7 +30,8 @@ public final class EntityUtil {
   private EntityUtil() {}
 
   /** Returns true if any entity in the collection has the attribute key, in id or description. */
-  static final <T> boolean hasAttributeKey(Collection<Entity> entities, AttributeKey<T> key) {
+  public static final <T> boolean hasAttributeKey(
+      Collection<Entity> entities, AttributeKey<T> key) {
     return entities.stream()
         .anyMatch(
             e -> e.getId().asMap().containsKey(key) || e.getDescription().asMap().containsKey(key));
@@ -178,4 +180,30 @@ public static final Collection<Entity> mergeEntities(
     }
     return entities.values();
   }
+
+  /**
+   * Returns a new, merged {@link Resource} by merging the {@code base} {@code Resource} with the
+   * {@code next} {@code Resource}. In case of a collision, the "next" {@code Resource} takes
+   * precedence.
+   *
+   * @param base the {@code Resource} into which we merge new values.
+   * @param next the {@code Resource} that will be merged with {@code base}.
+   * @return the newly merged {@code Resource}.
+   */
+  public static Resource merge(Resource base, @Nullable Resource next) {
+    if (next == null || next == Resource.empty()) {
+      return base;
+    }
+    // Merge Algorithm from
+    // https://github.com/open-telemetry/opentelemetry-specification/blob/main/oteps/entities/0264-resource-and-entities.md#entity-merging-and-resource
+    Collection<Entity> entities = EntityUtil.mergeEntities(base.getEntities(), next.getEntities());
+    RawAttributeMergeResult attributeResult =
+        EntityUtil.mergeRawAttributes(base.getRawAttributes(), next.getRawAttributes(), entities);
+    // Remove entiites that are conflicting with raw attributes, and therefore in an unknown state.
+    entities.removeAll(attributeResult.getConflicts());
+    // Now figure out schema url for overall resource.
+    String schemaUrl =
+        EntityUtil.mergeResourceSchemaUrl(entities, base.getSchemaUrl(), next.getSchemaUrl());
+    return Resource.create(attributeResult.getAttributes(), schemaUrl, entities);
+  }
 }