Merge pull request #143 from prometheus/beorn7/sd

Update documentation for new Consul meta-labels.

content/docs/operating/configuration.md

@@ -183,9 +183,12 @@ Catalog API.
 
 The following meta labels are available on targets during relabeling:
 
+* `__meta_consul_address`: the address of the target 
 * `__meta_consul_node`: the node name defined for the target
 * `__meta_consul_tags`: the list of tags of the target joined by the tag separator
 * `__meta_consul_service`: the name of the service the target belongs to
+* `__meta_consul_service_address`: the service address of the target 
+* `__meta_consul_service_port`: the service port of the target 
 * `__meta_consul_dc`: the datacenter name for the target
 
 ```
@@ -206,6 +209,12 @@ services:
 [ tag_separator: <string> | default = , ]
 ```
 
+Note that the IP number and port used to scrape the targets is assembled as
+`<__meta_consul_address>:<__meta_consul_service_port`. However, in some
+Consul setups, the relevant address is in `__meta_consul_service_address`.
+In those cases, you can use the [relabel](#target-relabeling-relabel_config)
+feature to replace the special `__address__` label.
+
 ### Zookeeper Serverset SD configurations `<serverset_sd_config>`
 
 Serverset SD configurations allow retrieving scrape targets from [Serversets]