Document the new fields in Configuration's tracing section. (#983)

* Document the new fields in Configuration's tracing section.

* Also document the 'Metrics' section

daprdocs/content/en/operations/configuration/configuration-overview.md

@@ -15,7 +15,7 @@ In self hosted mode the Dapr configuration is a configuration file, for example
 
 A Dapr sidecar can also apply a configuration by using a ```--config``` flag to the file path with ```dapr run``` CLI command.
 
-#### Kubernetes sidecar 
+#### Kubernetes sidecar
 In Kubernetes mode the Dapr configuration is a Configuration CRD, that is applied to the cluster. For example;
 
 ```bash
@@ -43,6 +43,7 @@ Note: There are more [Kubernetes annotations]({{< ref "kubernetes-annotations.md
 
 The following configuration settings can be applied to Dapr application sidecars;
 - [Tracing](#tracing)
+- [Metrics](#metrics)
 - [Middleware](#middleware)
 - [Scoping secrets for secret stores](#scoping-secrets-for-secret-stores)
 - [Access control allow lists for service invocation](#access-control-allow-lists-for-service-invocation)
@@ -56,14 +57,17 @@ The `tracing` section under the `Configuration` spec contains the following prop
 
 ```yml
 tracing:
-    samplingRate: "1"
+  samplingRate: "1"
+  zipkin:
+    endpointAddress: "http://zipkin.default.svc.cluster.local:9411/api/v2/spans"
 ```
 
 The following table lists the properties for tracing:
 
 | Property     | Type   | Description |
 |--------------|--------|-------------|
-| samplingRate | string | Set sampling rate for tracing to be enabled or disabled. 
+| `samplingRate` | string | Set sampling rate for tracing to be enabled or disabled.
+| `zipkin.endpointAddress` | string | Set the Zipkin server address.
 
 
 `samplingRate` is used to enable or disable the tracing. To disable the sampling rate ,
@@ -71,9 +75,28 @@ set `samplingRate : "0"` in the configuration. The valid range of samplingRate i
 
 See [Observability distributed tracing]({{< ref "tracing.md" >}}) for more information
 
+#### Metrics
+
+The metrics section can be used to enable or disable metrics for an application.
+
+The `metrics` section under the `Configuration` spec contains the following properties:
+
+```yml
+metrics:
+  enabled: true
+```
+
+The following table lists the properties for metrics:
+
+| Property     | Type   | Description |
+|--------------|--------|-------------|
+| `enabled` | boolean | Whether metrics should to be enabled.
+
+See [metrics documentation]({{< ref "metrics.md" >}}) for more information
+
 #### Middleware
 
-Middleware configuration set named Http pipeline middleware handlers 
+Middleware configuration set named Http pipeline middleware handlers
 The `httpPipeline` section under the `Configuration` spec contains the following properties:
 
 ```yml
@@ -128,14 +151,14 @@ spec:
     trustDomain: "public"
     policies:
     - appId: app1
-      defaultAction: deny 
+      defaultAction: deny
       trustDomain: 'public'
-      namespace: "default" 
+      namespace: "default"
       operations:
-      - name: /op1 
+      - name: /op1
-        httpVerb: ['POST', 'GET'] 
+        httpVerb: ['POST', 'GET']
         action: deny
-      - name: /op2/* 
+      - name: /op2/*
         httpVerb: ["*"]
         action: allow
 ```