Update Smart Agent docs (#199)

Author: rmfitzpatrick

docs/signalfx-smart-agent-migration.md

@@ -4,8 +4,9 @@ The [SignalFx Smart Agent's](https://github.com/signalfx/signalfx-agent/blob/mas
 metric monitors allow real-time insights into how your target services and
 applications are performing.  These metric gathering utilities have an
 equivalent counterpart in the OpenTelemetry Collector, the metric receiver.
-The [Smart Agent Receiver](./README.md) is a wrapper utility that allows the
-embedding of Smart Agent monitors within your Collector pipelines.
+The [Smart Agent Receiver](../internal/receiver/smartagentreceiver/README.md)
+is a wrapper utility that allows the embedding of Smart Agent monitors within
+your Collector pipelines.
 
 Based on the relocation of your desired monitor configurations in your Collector
 deployment, the Smart Agent Receiver works in much the same way your Smart Agent
@@ -29,6 +30,8 @@ collectd:
   writeQueueLimitLow: 600000
 
 monitors:
+  - type: signalfx-forwarder
+    listenAddress: 0.0.0.0:9080
   - type: collectd/activemq
     discoveryRule: container_image =~ "activemq" && private_port == 1099
     extraDimensions:
@@ -41,7 +44,10 @@ monitors:
       my_other_dimension: my_other_dimension_value
 ```
 
-Here is an equivalent, recommended Collector configuration utilizing the
+Below is an equivalent, recommended Collector configuration.  Notice that the
+`signalfx-forwarder` monitor's associated `smartagent/signalfx-forwarder` receiver instance
+is part of a `traces` pipeline using the `sapm` exporter.  The additional metric
+monitors utilize the
 [Receiver Creator](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/master/receiver/receivercreator/README.md):
 
 ```yaml
@@ -57,20 +63,23 @@ extensions:
       writeQueueLimitLow: 600000
 
 receivers:
+  smartagent/signalfx-forwarder:
+    type: signalfx-forwarder
+    listenAddress: 0.0.0.0:9080
   receiver_creator:
     receivers:
       smartagent/activemq:
-        rule: type.port && pod.name == "activemq" && port == 1099
+        rule: type == "port" && pod.name matches "activemq" && port == 1099
         config:
           type: collectd/activemq
           extraDimensions:
             my_dimension: my_dimension_value
       smartagent/apache:
-        rule: type.port && pod.name == "apache" && port == 80
+        rule: type == "port" && pod.name matches "apache" && port == 80
         config:
           type: collectd/apache
       smartagent/postgresql:
-        rule: type.port && pod.name == "postgresql" && port == 7199
+        rule: type == "port" && pod.name matches "postgresql" && port == 7199
         config:
           type: postgresql
           extraDimensions:
@@ -102,6 +111,9 @@ exporters:
   signalfx:
     access_token: "${SIGNALFX_ACCESS_TOKEN}"
     realm: us1
+  sapm:
+    access_token: "${SIGNALFX_ACCESS_TOKEN}"
+    endpoint: https://ingest.us1.signalfx.com/v2/trace
 
 service:
   extensions:
@@ -115,4 +127,11 @@ service:
         - resourcedetection
       exporters:
         - signalfx
+    traces:
+      receivers:
+        - smartagent/signalfx-forwarder
+      processors:
+        - resourcedetection
+      exporters:
+        - sapm
 ```

internal/receiver/smartagentreceiver/README.md

@@ -15,6 +15,9 @@ Each `smartagent` receiver configuration acts a drop-in replacement for each sup
 [`receivercreator`](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/master/receiver/receivercreator/README.md)
 and associated [Observer extensions](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/master/extension/observer/README.md)
 should be used.
+1. The [`signalfx-forwarder`](https://github.com/signalfx/signalfx-agent/blob/master/docs/monitors/signalfx-forwarder.md)
+monitor should be made part of a `traces` pipeline utilizing the [`sapm`
+exporter](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/exporter/sapmexporter/README.md)
 1. All metric content replacement and transformation rules should utilize existing
 [Collector processors](https://github.com/open-telemetry/opentelemetry-collector/blob/master/processor/README.md).
 1. Monitors with [dimension property and tag update
@@ -41,6 +44,8 @@ Example:
 
 ```yaml
 receivers:
+  smartagent/signalfx-forwarder:
+    type: signalfx-forwarder
   smartagent/postgresql:
     type: postgresql
     host: mypostgresinstance
@@ -63,6 +68,7 @@ processors:
 
 exporters:
   signalfx:
+  sapm:
 
 service:
   pipelines:
@@ -81,6 +87,13 @@ service:
         - resourcedetection
       exporters:
         - signalfx
+    traces:
+      receivers:
+        - smartagent/signalfx-forwarder
+      processors:
+        - resourcedetection
+      exporters:
+        - sapm
 ```
 
 For a more detailed description of migrating your Smart Agent monitor usage to the Splunk Distribution of