OpenTracing support

pom.xml

@@ -59,6 +59,7 @@
         <module>riptide-httpclient</module>
         <module>riptide-idempotency</module>
         <module>riptide-metrics</module>
+        <module>riptide-opentracing</module>
         <module>riptide-problem</module>
         <module>riptide-soap</module>
         <module>riptide-spring-boot-autoconfigure</module>
@@ -133,6 +134,11 @@
                 <artifactId>riptide-metrics</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>org.zalando</groupId>
+                <artifactId>riptide-opentracing</artifactId>
+                <version>${project.version}</version>
+            </dependency>
             <dependency>
                 <groupId>org.zalando</groupId>
                 <artifactId>riptide-problem</artifactId>

riptide-bom/pom.xml

@@ -68,6 +68,10 @@
                 <artifactId>riptide-metrics</artifactId>
                 <version>3.0.0-SNAPSHOT</version>
             </dependency>
+            <dependency>
+                <groupId>org.zalando</groupId>
+                <artifactId>riptide-opentracing</artifactId>
+            </dependency>
             <dependency>
                 <groupId>org.zalando</groupId>
                 <artifactId>riptide-problem</artifactId>

riptide-failsafe/src/main/java/org/zalando/riptide/failsafe/CompositeRetryListener.java

@@ -10,6 +10,7 @@
 
 import static org.apiguardian.api.API.Status.EXPERIMENTAL;
 
+// TODO package private?
 @API(status = EXPERIMENTAL)
 public final class CompositeRetryListener implements RetryListener {
 

riptide-failsafe/src/main/java/org/zalando/riptide/failsafe/FailsafePlugin.java

@@ -10,6 +10,7 @@
 import net.jodah.failsafe.function.CheckedConsumer;
 import org.apiguardian.api.API;
 import org.springframework.http.client.ClientHttpResponse;
+import org.zalando.riptide.Attribute;
 import org.zalando.riptide.Plugin;
 import org.zalando.riptide.RequestArguments;
 import org.zalando.riptide.RequestExecution;
@@ -27,6 +28,8 @@
 @AllArgsConstructor(access = PRIVATE)
 public final class FailsafePlugin implements Plugin {
 
+    public static final Attribute<Integer> ATTEMPTS = Attribute.generate();
+
     private final ImmutableList<? extends Policy<ClientHttpResponse>> policies;
     private final ScheduledExecutorService scheduler;
     private final Predicate<RequestArguments> predicate;
@@ -56,18 +59,17 @@ public RequestExecution aroundDispatch(final RequestExecution execution) {
 
             return Failsafe.with(select(arguments))
                     .with(scheduler)
-                    .getStageAsync(() -> execution.execute(arguments));
+                    .getStageAsync(context -> execution
+                            .execute(withAttempts(arguments, context.getAttemptCount())));
         };
     }
 
-
     private Policy<ClientHttpResponse>[] select(final RequestArguments arguments) {
         final Stream<Policy<ClientHttpResponse>> stream = policies.stream()
                 .filter(skipRetriesIfNeeded(arguments))
                 .map(withRetryListener(arguments));
 
-        @SuppressWarnings("unchecked")
-        final Policy<ClientHttpResponse>[] policies = stream.toArray(Policy[]::new);
+        @SuppressWarnings("unchecked") final Policy<ClientHttpResponse>[] policies = stream.toArray(Policy[]::new);
 
         return policies;
     }
@@ -84,13 +86,21 @@ private UnaryOperator<Policy<ClientHttpResponse>> withRetryListener(final Reques
             if (policy instanceof RetryPolicy) {
                 final RetryPolicy<ClientHttpResponse> retryPolicy = (RetryPolicy<ClientHttpResponse>) policy;
                 return retryPolicy.copy()
-                        .onRetry(new RetryListenerAdapter(listener, arguments));
+                        .onFailedAttempt(new RetryListenerAdapter(listener, arguments));
             } else {
                 return policy;
             }
         };
     }
 
+    private RequestArguments withAttempts(final RequestArguments arguments, final int attempts) {
+        if (attempts == 0) {
+            return arguments;
+        }
+
+        return arguments.withAttribute(ATTEMPTS, attempts);
+    }
+
     @VisibleForTesting
     @AllArgsConstructor
     static final class RetryListenerAdapter implements CheckedConsumer<ExecutionAttemptedEvent<ClientHttpResponse>> {

riptide-faults/src/test/java/org/zalando/riptide/faults/TransientFaultExceptionTest.java

@@ -5,10 +5,10 @@
 import java.io.IOException;
 import java.util.concurrent.TimeoutException;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.hasItemInArray;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.is;
-import static org.hamcrest.MatcherAssert.assertThat;
 
 final class TransientFaultExceptionTest {
 

riptide-opentracing/README.md

@@ -0,0 +1,185 @@
+# Riptide: OpenTracing
+
+[![Spider web](../docs/spider-web.jpg)](https://pixabay.com/photos/cobweb-drip-water-mirroring-blue-3725540/)
+
+[![Build Status](https://img.shields.io/travis/zalando/riptide/master.svg)](https://travis-ci.org/zalando/riptide)
+[![Coverage Status](https://img.shields.io/coveralls/zalando/riptide/master.svg)](https://coveralls.io/r/zalando/riptide)
+[![Code Quality](https://img.shields.io/codacy/grade/1fbe3d16ca544c0c8589692632d114de/master.svg)](https://www.codacy.com/app/whiskeysierra/riptide)
+[![Javadoc](https://www.javadoc.io/badge/org.zalando/riptide-metrics.svg)](http://www.javadoc.io/doc/org.zalando/riptide-metrics)
+[![Release](https://img.shields.io/github/release/zalando/riptide.svg)](https://github.com/zalando/riptide/releases)
+[![Maven Central](https://img.shields.io/maven-central/v/org.zalando/riptide-metrics.svg)](https://maven-badges.herokuapp.com/maven-central/org.zalando/riptide-metrics)
+[![OpenTracing](https://img.shields.io/badge/OpenTracing-enabled-blue.svg)](http://opentracing.io)
+[![License](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/zalando/riptide/master/LICENSE)
+
+*Riptide: OpenTracing* adds sophisticated [OpenTracing](https://opentracing.io/) support to *Riptide*.
+
+## Example
+
+```java
+Http.builder()
+    .plugin(new OpenTracingPlugin(tracer))
+    .build();
+```
+
+## Features
+
+- Client span lifecycle management
+- Span context injection into HTTP headers of requests
+- Extensible span decorators for tags and logs
+- Seamless integration with [Riptide: Failsafe](../riptide-failsafe)
+
+## Dependencies
+
+- Java 8
+- Riptide Core
+- [OpenTracing Java API](https://opentracing.io/guides/java/)
+- [Riptide: Failsafe](../riptide-failsafe) (optional)
+
+## Installation
+
+Add the following dependency to your project:
+
+```xml
+<dependency>
+    <groupId>org.zalando</groupId>
+    <artifactId>riptide-opentracing</artifactId>
+    <version>${riptide.version}</version>
+</dependency>
+```
+
+## Configuration
+
+```java
+Http.builder()
+    .baseUrl("https://www.example.com")
+    .plugin(new OpenTracingPlugin(tracer))
+    .build();
+```
+
+The following tags/logs are supported out of the box:
+
+| Tag/Log Field        | Decorator                      | Example                           |
+|----------------------|--------------------------------|-----------------------------------|
+| `component`          | `ComponentSpanDecorator`       | `Riptide`                         |
+| `span.kind`          | `SpanKindSpanDecorator`        | `client`                          |
+| `peer.hostname`      | `PeerSpanDecorator`            | `www.github.com`                  |
+| `peer.port`          | `PeerSpanDecorator`            | `80`                              |
+| `http.method`        | `HttpMethodSpanDecorator`      | `GET`                             |
+| `http.url`           | `HttpUrlSpanDecorator`         | `https://www.github.com/users/me` |
+| `http.path`          | `HttpPathSpanDecorator`        | `/users/{user_id}`                |
+| `http.status_code`   | `HttpStatusCodeSpanDecorator`  | `200`                             |
+| `error`              | `ErrorSpanDecorator`           | `false`                           |
+| `error.kind` (log)   | `ErrorSpanDecorator`           | `SocketTimeoutException`          |
+| `error.object` (log) | `ErrorSpanDecorator`           | (exception instance)              |
+| `retry`              | `RetrySpanDecorator`           | `true`                            |
+| `retry_number` (log) | `RetrySpanDecorator`           | `3`                               |
+| `*`                  | `CallSiteSpanDecorator`        | `admin=true`                      |
+| `*`                  | `StaticTagSpanDecorator`       | `aws.region=eu-central-1`         |
+| `*`                  | `UriVariablesTagSpanDecorator` | user_id=me                        |
+
+### Notice
+
+**Be aware**: The `http.url` tag is disabled by default because the full request URI may contain
+sensitive, [*personal data*](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation).
+As an alternative we introduced the `http.path` tag which favors the URI template over the
+already expanded version. That has the additional benefit of a significant lower cardinality
+compared to what `http.url` would provide. 
+
+If you still want to enable it, you can do so by just registering the missing span decorator:
+
+```java
+new OpenTracingPlugin(tracer)
+    .withAdditionalSpanDecorators(new HttpUrlSpanDecorator())
+```
+
+### Span Decorators
+
+Span decorators are a simple, yet powerful tool to manipulate the span, i.e. they allow you to
+add tags, logs and baggage to spans. The default set of decorators can be extended by using 
+`OpenTracingPlugin#withAdditionalSpanDecorators(..)`:
+
+```java
+new OpenTracingPlugin(tracer)
+    .withAdditionalSpanDecorators(new StaticSpanDecorator(singletonMap(
+            "environment", "local"
+    )))
+```
+
+If the default span decorators are not desired you can replace them completely using
+`OpenTracingPlugin#withSpanDecorators(..)`:
+
+```java
+new OpenTracingPlugin(tracer)
+        .withSpanDecorators(
+            new ComponentSpanDecorator("MSIE"),
+            new SpanKindSpanDecorator(Tags.SPAN_KIND_CONSUMER),
+            new PeerSpanDecorator(),
+            new HttpMethodSpanDecorator(),
+            new HttpPathSpanDecorator(),
+            new HttpUrlSpanDecorator(),
+            new HttpStatusCodeSpanDecorator(),
+            new ErrorSpanDecorator(),
+            new CallSiteSpanDecorator())
+```
+
+## Usage
+
+Typically you won't need to do anything at the call-site regarding OpenTracing, i.e.
+your usages of Riptide should work exactly as before:
+
+```java
+http.get("/users/{id}", userId)
+    .dispatch(series(),
+        on(SUCCESSFUL).call(User.class, this::greet),
+        anySeries().call(problemHandling()))
+```
+
+### Operation Name
+
+By default the HTTP method will be used as the operation name, which might not fit your needs.
+Since deriving a meaningful operation name from request arguments alone is unreliable, you can
+specify the `OpenTracingPlugin.OPERATION_NAME` request attribute to override the default:
+
+```java
+http.get("/users/{id}", userId)
+    .attribute(OpenTracingPlugin.OPERATION_NAME, "get_user")
+    .dispatch(series(),
+        on(SUCCESSFUL).call(User.class, this::greet),
+        anySeries().call(problemHandling()))
+```
+
+### Call-Site Tags
+
+Assuming you have the [`CallSiteSpanDecorator`](#span-decorators) registered (it is by default), you can also
+specify custom tags based on context information which wouldn't be available within the plugin
+anymore:
+
+```java
+http.get("/users/{id}", userId)
+    .attribute(OpenTracingPlugin.TAGS, singletonMap("retry", "true"))
+    .dispatch(series(),
+        on(SUCCESSFUL).call(User.class, this::greet),
+        anySeries().call(problemHandling()))
+```
+
+### URI Variables as Tags
+
+URI templates are not just safer to use (see [Configuration](#notice)), they can also be used to
+generate tags from URI variables. Given you have the `UriVariablesTagSpanDecorator` registered
+then the following will produce a `user_id=123` tag:
+
+```java
+http.get("/users/{user_id}", 123)
+```
+
+The same warning applies as mentioned before regarding [`http.url`](#notice). This feature may
+expose *personal data* and should be used with care.
+
+## Getting Help
+
+If you have questions, concerns, bug reports, etc., please file an issue in this repository's [Issue Tracker](../../../../issues).
+
+## Getting Involved/Contributing
+
+To contribute, simply open a pull request and add a brief description (1-2 sentences) of your addition or change. For
+more details, check the [contribution guidelines](../.github/CONTRIBUTING.md).

riptide-opentracing/pom.xml

@@ -0,0 +1,68 @@
+<?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>org.zalando</groupId>
+        <artifactId>riptide-parent</artifactId>
+        <version>3.0.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>riptide-opentracing</artifactId>
+
+    <name>Riptide: OpenTracing</name>
+    <description>Client side response routing</description>
+
+    <properties>
+        <opentracing.version>0.32.0</opentracing.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.zalando</groupId>
+            <artifactId>riptide-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.opentracing</groupId>
+            <artifactId>opentracing-api</artifactId>
+            <version>${opentracing.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.zalando</groupId>
+            <artifactId>riptide-failsafe</artifactId>
+            <!-- Needed for retry tags -->
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>io.opentracing</groupId>
+            <artifactId>opentracing-mock</artifactId>
+            <version>${opentracing.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.github.rest-driver</groupId>
+            <artifactId>rest-client-driver</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.opentracing.contrib</groupId>
+            <artifactId>opentracing-concurrent</artifactId>
+            <version>0.2.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>4.5.7</version>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>commons-logging</groupId>
+                    <artifactId>commons-logging</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+    </dependencies>
+
+</project>

riptide-opentracing/src/main/java/org/zalando/riptide/opentracing/ExtensionFields.java

@@ -0,0 +1,14 @@
+package org.zalando.riptide.opentracing;
+
+public final class ExtensionFields {
+
+    /**
+     * In combination with {@link ExtensionTags#RETRY retry tag}, this field holds the number of the retry attempt.
+     */
+    public static final String RETRY_NUMBER = "retry_number";
+
+    private ExtensionFields() {
+
+    }
+
+}