Add basic docs for tracing

docs/tracing.md

@@ -0,0 +1,38 @@
+---
+title: "Tracing"
+date: 2020-05-13T12:09:00+01:00
+weight: 55
+geekdocRepo: https://github.com/owncloud/ocis
+geekdocEditPath: edit/master/docs
+geekdocFilePath: tracing.md
+---
+
+By default, we use [Jaeger](https://www.jaegertracing.io) for request tracing within oCIS. You can follow these steps
+to get started:
+
+1. Start Jaeger by using the all-in-one docker image:
+    ```console
+    docker run -d --name jaeger \
+      -e COLLECTOR_ZIPKIN_HTTP_PORT=9411 \
+      -p 5775:5775/udp \
+      -p 6831:6831/udp \
+      -p 6832:6832/udp \
+      -p 5778:5778 \
+      -p 16686:16686 \
+      -p 14268:14268 \
+      -p 14250:14250 \
+      -p 9411:9411 \
+      jaegertracing/all-in-one:1.17
+    ```
+2. Every single oCIS service has its own environment variables for enabling and configuring tracing. You can, for example,
+enable tracing in Reva when starting the oCIS single binary like this:
+    ```console
+    REVA_TRACING_ENABLED=true \
+    REVA_TRACING_ENDPOINT=localhost:6831 \
+    REVA_TRACING_COLLECTOR=http://localhost:14268/api/traces \
+    ./bin/ocis server
+    ```
+3. Make the actual request that you want to trace.
+4. Open up the [Jaeger UI](http://localhost:16686) to analyze request traces.
+
+For more information on Jaeger, please refer to their [Documentation](https://www.jaegertracing.io/docs/1.17/).