| .. 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. |