63 lines
1.9 KiB
Markdown
63 lines
1.9 KiB
Markdown
## REST Spark
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This project provides a simple REST API using the [Spark web framework][1]. Even if the framework is not directly
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supported, manual instrumentation is used to trace one of the endpoints. A ``MongoClient`` is traced so that
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Mongo calls are part of the Spark trace.
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[1]: http://sparkjava.com/
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### Run the demo
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#### Prerequisites
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Be sure to build the project so that the latest version of ``dd-trace-java`` components are used. You can build
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all libraries and examples launching from the ``dd-trace-java`` root folder:
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```bash
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./gradlew clean shadowJar
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```
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Then you can prepare the distributable version of the ``rest-spark`` as follows:
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```bash
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cd examples/rest-spark
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./gradlew installDist
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```
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Then you can start all services via Docker:
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```bash
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DD_API_KEY=<your_datadog_api_key> docker-compose up -d
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```
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A valid ``DD_API_KEY`` is required to post collected traces to the Datadog backend.
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#### Run the application
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Launch the application using the run wrapper you've built during the ``installDist`` step:
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```bash
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JAVA_OPTS=-javaagent:../../dd-java-agent/build/libs/dd-java-agent-{version}.jar -Ddd.service.name=rest-spark build/install/rest-spark/bin/rest-spark
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```
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``0.2.0-SNAPSHOT`` is an example of what ``{version}`` looks like.
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### Generate traces
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#### With your web browser
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Once the application runs. Go to the following url:
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* [http://localhost:4567/key/something][2]
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* [http://localhost:4567/key/something_else][3]
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Then get back to Datadog and wait a bit to see a trace coming.
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[2]: http://localhost:4567/key/something
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[3]: http://localhost:4567/key/something_else
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#### Auto-instrumentation with the `dd-trace-agent`
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The instrumentation is entirely done by the Java Agent which embed a set of rules that automatically recognizes &
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instruments:
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- The Mongo client
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The Java Agent embeds the [OpenTracing Java Agent](https://github.com/opentracing-contrib/java-agent).
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