New rest observation instrumentation

implementation/rest-observation/pom.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>io.smallrye.opentelemetry</groupId>
+        <artifactId>smallrye-opentelemetry-parent</artifactId>
+        <version>2.6.1-SNAPSHOT</version>
+        <relativePath>../../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>smallrye-opentelemetry-rest-observation</artifactId>
+    <name>SmallRye OpenTelemetry: REST Observation</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.smallrye.opentelemetry</groupId>
+            <artifactId>smallrye-opentelemetry-api</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>io.smallrye.opentelemetry</groupId>
+            <artifactId>smallrye-opentelemetry-observation-otel-bridge</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>jakarta.enterprise</groupId>
+            <artifactId>jakarta.enterprise.cdi-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>jakarta.ws.rs</groupId>
+            <artifactId>jakarta.ws.rs-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>io.opentelemetry.semconv</groupId>
+            <artifactId>opentelemetry-semconv</artifactId>
+        </dependency>
+    </dependencies>
+</project>

implementation/rest-observation/src/main/java/io/smallrye/opentelemetry/implementation/rest.observation/ObservationClientFilter.java

@@ -0,0 +1,190 @@
+package io.smallrye.opentelemetry.implementation.rest.observation;
+
+import static io.opentelemetry.semconv.SemanticAttributes.HTTP_METHOD;
+import static io.opentelemetry.semconv.SemanticAttributes.HTTP_REQUEST_METHOD;
+import static io.opentelemetry.semconv.SemanticAttributes.HTTP_RESPONSE_STATUS_CODE;
+import static io.opentelemetry.semconv.SemanticAttributes.HTTP_ROUTE;
+import static io.opentelemetry.semconv.SemanticAttributes.HTTP_STATUS_CODE;
+import static io.smallrye.opentelemetry.api.OpenTelemetryConfig.INSTRUMENTATION_NAME;
+import static io.smallrye.opentelemetry.api.OpenTelemetryConfig.INSTRUMENTATION_VERSION;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+
+import java.util.List;
+
+import jakarta.inject.Inject;
+import jakarta.ws.rs.client.ClientRequestContext;
+import jakarta.ws.rs.client.ClientRequestFilter;
+import jakarta.ws.rs.client.ClientResponseContext;
+import jakarta.ws.rs.client.ClientResponseFilter;
+import jakarta.ws.rs.ext.Provider;
+
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.api.metrics.LongHistogram;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.context.Scope;
+import io.opentelemetry.context.propagation.TextMapSetter;
+import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
+import io.opentelemetry.instrumentation.api.instrumenter.InstrumenterBuilder;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientAttributesGetter;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientExperimentalMetrics;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
+import io.opentelemetry.instrumentation.api.internal.SemconvStability;
+
+@Provider
+public class ObservationClientFilter implements ClientRequestFilter, ClientResponseFilter {
+    private Instrumenter<ClientRequestContext, ClientResponseContext> instrumenter;
+    private LongHistogram durationHistogram;
+
+    // RESTEasy requires no-arg constructor for CDI injection: https://issues.redhat.com/browse/RESTEASY-1538
+    public ObservationClientFilter() {
+    }
+
+    @Inject
+    public ObservationClientFilter(final OpenTelemetry openTelemetry) {
+        ClientAttributesExtractor clientAttributesExtractor = new ClientAttributesExtractor();
+
+        // TODO - The Client Span name is only "HTTP {METHOD_NAME}": https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/semantic_conventions/http.md#name
+        final InstrumenterBuilder<ClientRequestContext, ClientResponseContext> builder = Instrumenter.builder(
+                openTelemetry,
+                INSTRUMENTATION_NAME,
+                HttpSpanNameExtractor.create(clientAttributesExtractor));
+        builder.setInstrumentationVersion(INSTRUMENTATION_VERSION);
+
+        this.instrumenter = builder
+                .setSpanStatusExtractor(HttpSpanStatusExtractor.create(clientAttributesExtractor))
+                .addAttributesExtractor(HttpClientAttributesExtractor.create(clientAttributesExtractor))
+//                .addOperationMetrics(HttpClientMetrics.get()) // This will include the duration histogram
+                .addOperationMetrics(HttpClientExperimentalMetrics.get())
+                .buildClientInstrumenter(new ClientRequestContextTextMapSetter());
+
+        final Meter meter = openTelemetry.getMeter(INSTRUMENTATION_NAME);
+        //fixme use new https://opentelemetry.io/docs/specs/semconv/http/http-metrics/#metric-httpclientrequestduration
+        durationHistogram = meter.histogramBuilder("http.client.duration")
+                .setDescription("The duration of an outbound HTTP request")
+                .ofLongs()
+                .setUnit("ms")
+                .build();
+    }
+
+    @Override
+    public void filter(final ClientRequestContext request) {
+        // CDI is not available in some contexts even if this library is available on the CP
+        if (instrumenter != null) {
+            Context parentContext = Context.current();
+            if (instrumenter.shouldStart(parentContext, request)) {
+                Context spanContext = instrumenter.start(parentContext, request);
+                Scope scope = spanContext.makeCurrent();
+                request.setProperty("otel.span.client.context", spanContext);
+                request.setProperty("otel.span.client.parentContext", parentContext);
+                request.setProperty("otel.span.client.scope", scope);
+            }
+        }
+        if (durationHistogram != null) {
+            request.setProperty("otel.metrics.client.start", System.currentTimeMillis());
+        }
+    }
+
+    @Override
+    public void filter(final ClientRequestContext request, final ClientResponseContext response) {
+        // CDI is not available in some contexts even if this library is available on the CP
+        Context spanContext = (Context) request.getProperty("otel.span.client.context");
+        if (instrumenter != null) {
+            Scope scope = (Scope) request.getProperty("otel.span.client.scope");
+            if (scope == null) {
+                return;
+            }
+
+            try {
+                instrumenter.end(spanContext, request, response, null);
+            } finally {
+                scope.close();
+
+                request.removeProperty("otel.span.client.context");
+                request.removeProperty("otel.span.client.parentContext");
+                request.removeProperty("otel.span.client.scope");
+            }
+        }
+        if (durationHistogram != null) {
+            Long start = (Long) request.getProperty("otel.metrics.client.start");
+            if (start != null) {
+                try {
+                    durationHistogram.record(System.currentTimeMillis() - start,
+                            getHistogramAttributes(request, response),
+                            spanContext);
+                } finally {
+                    request.removeProperty("otel.metrics.client.start");
+                }
+            }
+        }
+    }
+
+    private Attributes getHistogramAttributes(ClientRequestContext request, ClientResponseContext response) {
+        AttributesBuilder builder = Attributes.builder();
+        builder.put(HTTP_ROUTE.getKey(), request.getUri().getPath().toString());// Fixme must contain a template /users/:userID?
+        if (SemconvStability.emitOldHttpSemconv()) {
+            builder.put(HTTP_METHOD, request.getMethod());// FIXME semantic conventions
+            builder.put(HTTP_STATUS_CODE, response.getStatus());
+        } else {
+            builder.put(HTTP_REQUEST_METHOD, request.getMethod());// FIXME semantic conventions
+            builder.put(HTTP_RESPONSE_STATUS_CODE, response.getStatus());
+        }
+        return builder.build();
+    }
+
+    private static class ClientRequestContextTextMapSetter implements TextMapSetter<ClientRequestContext> {
+        @Override
+        public void set(final ClientRequestContext carrier, final String key, final String value) {
+            if (carrier != null) {
+                carrier.getHeaders().put(key, singletonList(value));
+            }
+        }
+    }
+
+    private static class ClientAttributesExtractor
+            implements HttpClientAttributesGetter<ClientRequestContext, ClientResponseContext> {
+
+        @Override
+        public String getUrlFull(final ClientRequestContext request) {
+            return request.getUri().toString();
+        }
+
+        @Override
+        public String getServerAddress(final ClientRequestContext request) {
+            return request.getUri().getHost();
+        }
+
+        @Override
+        public Integer getServerPort(final ClientRequestContext request) {
+            return request.getUri().getPort();
+        }
+
+        @Override
+        public String getHttpRequestMethod(final ClientRequestContext request) {
+            return request.getMethod();
+        }
+
+        @Override
+        public List<String> getHttpRequestHeader(final ClientRequestContext request, final String name) {
+            return request.getStringHeaders().getOrDefault(name, emptyList());
+        }
+
+        @Override
+        public Integer getHttpResponseStatusCode(final ClientRequestContext request, final ClientResponseContext response,
+                final Throwable throwable) {
+            return response.getStatus();
+        }
+
+        @Override
+        public List<String> getHttpResponseHeader(final ClientRequestContext request, final ClientResponseContext response,
+                final String name) {
+            return response.getHeaders().getOrDefault(name, emptyList());
+        }
+    }
+}