DCAE Controller documentation DCAEGEN2-213
Issue-ID: DCAEGEN2-213
Change-Id: I7f2023b7f88b73eef852eca0bbf9086e14903cd6
Signed-off-by: Ralph Knag <rhknag@research.att.com>
diff --git a/docs/sections/components/component-specification/generated-configuration.rst b/docs/sections/components/component-specification/generated-configuration.rst
new file mode 100755
index 0000000..ba5ae4a
--- /dev/null
+++ b/docs/sections/components/component-specification/generated-configuration.rst
@@ -0,0 +1,114 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+.. _generated-configuration:
+
+Generated configuration
+=======================
+
+The DCAE platform relies on the component specification to generate the
+component’s application configuration JSON at deployment time. The
+component developer should expect to use this configuration JSON in
+their application to provision themselves.
+
+Pro-tip: As you build your component specification, you can use the
+:any:`dcae-cli dev command <walkthrough-dev>` to view what
+the resulting application configuration will look like.
+
+Streams and services
+--------------------
+
+For both Docker and CDAP, when your component is deployed, any
+``streams`` and ``services/calls`` you specified will be injected into
+your configuration under the following well known structure. Your
+component is required to parse this information if you have any
+connectivity to DMaaP or are calling another DCAE component.
+
+More details about the DMaaP connection objects are found
+:doc:`here <../dcae-cli/dmaap-connection-objects>`.
+
+This is best served with an example.
+
+The following component spec snippet (from String Matching):
+
+::
+
+ "streams":{
+ "subscribes": [{
+ "format": "VES_specification",
+ "version": "4.27.2",
+ "type": "message_router",
+ "config_key" : "mr_input"
+ }],
+ "publishes": [{
+ "format": "VES_specification",
+ "version": "4.27.2",
+ "config_key": "mr_output",
+ "type": "message_router"
+ }]
+ },
+ "services":{
+ "calls": [{
+ "config_key" : "aai_broker_handle",
+ "verb": "GET",
+ "request": {
+ "format": "get_with_query_params",
+ "version": "1.0.0"
+ },
+ "response": {
+ "format": "aai_broker_response",
+ "version": "3.0.0"
+ }
+ }],
+ "provides": []
+ },
+
+Will turn into the following top level keys in your configuration (for
+CDAP, this will be under AppConfig)
+
+::
+
+ "streams_publishes":{
+ "mr_output":{ // notice the config key above
+ "aaf_password":"XXX",
+ "type":"message_router",
+ "dmaap_info":{
+ "client_role": null,
+ "client_id": null,
+ "location": null,
+ "topic_url":"XXX"
+ },
+ "aaf_username":"XXX"
+ }
+ },
+ "streams_subscribes":{
+ "mr_input":{ // notice the config key above
+ "aaf_password":"XXX",
+ "type":"message_router",
+ "dmaap_info":{
+ "client_role": null,
+ "client_id": null,
+ "location": null,
+ "topic_url":"XXX"
+ },
+ "aaf_username":"XXX"
+ }
+ },
+ "services_calls":{
+ "aai_broker_handle":[ // notice the config key above
+ "SOME_IP:32768" // based on deployment time, just an example
+ ]
+ }
+
+These keys will always be populated regardless of whether they are
+empty. So the minimal you will get, in the case of a component that
+provides an HTTP service and does not call any services and has no
+streams, is:
+
+::
+
+ "streams_publishes":{},
+ "streams_subscribes":{},
+ "services_calls":{}
+
+Thus your component should expect these well-known top level keys.