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Diffstat (limited to 'plugins/plugins-event/plugins-event-carrier/plugins-event-carrier-restserver/src/site-docs')
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diff --git a/plugins/plugins-event/plugins-event-carrier/plugins-event-carrier-restserver/src/site-docs/adoc/fragments/ct-restserver-io.adoc b/plugins/plugins-event/plugins-event-carrier/plugins-event-carrier-restserver/src/site-docs/adoc/fragments/ct-restserver-io.adoc new file mode 100644 index 000000000..c6c9a0865 --- /dev/null +++ b/plugins/plugins-event/plugins-event-carrier/plugins-event-carrier-restserver/src/site-docs/adoc/fragments/ct-restserver-io.adoc @@ -0,0 +1,134 @@ +// +// ============LICENSE_START======================================================= +// Copyright (C) 2016-2018 Ericsson. All rights reserved. +// ================================================================================ +// This file is licensed under the CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL LICENSE +// Full license text at https://creativecommons.org/licenses/by/4.0/legalcode +// +// SPDX-License-Identifier: CC-BY-4.0 +// ============LICENSE_END========================================================= +// +// @author Sven van der Meer (sven.van.der.meer@ericsson.com) +// + +== REST Server IO + +APEX supports a REST server for input and output. + +The REST server plugin always uses a synchronous mode. +A client does a HTTP GET on the APEX REST server with the input event and receives the generated output event in the server reply. +This means that for the REST server there has to always to be an input with an associated output. +Input or output only are not permitted. + +The plugin will start a Grizzly server as REST server for a normal APEX engine. +If the APEX engine is executed as a servlet, for instance inside Tomcat, then Tomcat will be used as REST server (this case requires configuration on Tomcat as well). + +Some configuration restrictions apply for all scenarios: + +- Minimum port: 1024 +- Maximum port: 65535 +- The media type is `application/json`, so this plugin does only work with the JSON Event protocol. + +The URL the client calls is created using + +- the configured host and port, e.g. `http://localhost:12345` +- the standard path, e.g. `/apex/` +- the name of the input/output, e.g. `FirstConsumer/` +- the input or output name, e.g. `EventIn`. + +The examples above lead to the URL `http://localhost:12345/apex/FirstConsumer/EventIn`. + +A client can also get status information of the REST server using `/Status`, e.g. `http://localhost:12345/apex/FirstConsumer/Status`. + + +=== REST Server Stand-alone + +We need to configure a REST server input and a REST server output. +Input and output are associated with each other via there name. + +Timeouts for REST calls need to be set carefully. +If they are too short, the call might timeout before a policy finished creating an event. + +The following example configures the input named as `MyConsumer` and associates an output named `MyProducer` with it. + +[source%nowrap,json] +---- +"eventInputParameters": { + "MyConsumer": { + "carrierTechnologyParameters" : { + "carrierTechnology" : "RESTSERVER", <1> + "parameterClassName" : + "org.onap.policy.apex.plugins.event.carrier.restserver.RESTServerCarrierTechnologyParameters", + "parameters" : { + "standalone" : true, <2> + "host" : "localhost", <3> + "port" : 12345 <4> + } + }, + "eventProtocolParameters":{ + "eventProtocol" : "JSON" <5> + }, + "synchronousMode" : true, <6> + "synchronousPeer" : "MyProducer", <7> + "synchronousTimeout" : 500 <8> + } +} +---- +<1> set REST server as carrier technology +<2> set the server as stand-alone +<3> set the server host +<4> set the server listen port +<5> use JSON event protocol +<6> activate synchronous mode +<7> associate an output `MyProducer` +<8> set a timeout of 500 milliseconds + + +The following example configures the output named as `MyProducer` and associates the input `MyConsumer` with it. +Note that for the output there are no more paramters (such as host or port), since they are already configured in the associated input + +[source%nowrap,json] +---- +"eventOutputParameters": { + "MyProducer": { + "carrierTechnologyParameters":{ + "carrierTechnology" : "RESTSERVER", + "parameterClassName" : + "org.onap.policy.apex.plugins.event.carrier.restserver.RESTServerCarrierTechnologyParameters" + }, + "eventProtocolParameters":{ + "eventProtocol" : "JSON" + }, + "synchronousMode" : true, + "synchronousPeer" : "MyConsumer", + "synchronousTimeout" : 500 + } +} +---- + + +=== REST Server Stand-alone, multi input + +Any number of input/output pairs for REST servers can be configured. +For instance, we can configure an input `FirstConsumer` with output `FirstProducer` and an input `SecondConsumer` with output `SecondProducer`. +Important is that there is always one pair of input/output. + + +=== REST Server Stand-alone in Servlet + +If APEX is executed as a servlet, e.g. inside Tomcat, the configuration becomes easier since the plugin can now use Tomcat as the REST server. +In this scenario, there are not parameters (port, host, etc.) and the key `standalone` must not be used (or set to false). + +For the Tomcat configuration, we need to add the REST server plugin, e.g. + +[source%nowrap,xml] +---- +<servlet> + ... + <init-param> + ... + <param-value>org.onap.policy.apex.plugins.event.carrier.restserver</param-value> + </init-param> + ... +</servlet> +---- |