Merge pull request #117 from brian-brazil/serverset

Document serverset config

content/docs/operating/configuration.md

@@ -110,6 +110,10 @@ dns_sd_configs:
 consul_sd_configs:
   [ - <consul_sd_config> ... ]
 
+# List of Zookeeper Serverset service discovery configurations.
+serverset_sd_configs:
+  [ - <serverset_sd_config> ... ]
+
 # List of file service discovery configurations.
 file_sd_configs:
   [ - <file_sd_config> ... ]
@@ -202,6 +206,34 @@ services:
 [ tag_separator: <string> | default = , ]
 ```
 
+### Zookeeper Serverset SD configurations `<serverset_sd_config>`
+
+Serverset SD configurations allow retrieving scrape targets from [Serversets]
+(https://github.com/twitter/finagle/tree/master/finagle-serversets) which are
+stored in [Zookeeper](https://zookeeper.apache.org/). Serversets are commonly
+used by [Finagle](https://twitter.github.io/finagle/) and
+[Aurora](http://aurora.apache.org/).
+
+The following meta labels are available on targets during relabeling:
+
+* `__meta_serverset_path`: the full path to the serverset member node in Zookeeper
+* `__meta_serverset_endpoint_host`: the host of the default endpoint
+* `__meta_serverset_endpoint_port`: the port of the default endpoint
+* `__meta_serverset_endpoint_host_<endpoint>`: the host of the given endpoint
+* `__meta_serverset_endpoint_port_<endpoint>`: the port of the given endpoint
+* `__meta_serverset_status`: the status of the member
+
+```
+# The Zookeeper servers.
+servers:
+  - <host>
+# Paths can point to a single serverset, or the root of a tree of serversets.
+paths:
+  - <string>
+[ timeout: <duration> | default = 10s ]
+```
+
+Serverset data must be in the JSON format, the Thrift format is not currently supported.
 
 ### File-based SD configurations `<file_sd_config>`