Deployment of FHIR-based IPF IHE consumer endpoints
Every project that exposes consumer endpoints of FHIR-based IHE components needs to configure a web application container for them. Currently the following containers have been tested:
- Standalone Apache Tomcat
- Embedded in Spring Boot
Neccessary configuration steps for all these variants will be described in corresponding sections below.
Standalone Apache Tomcat
To make the IPF application deployable in the Apache Tomcat servlet container, a deployment descriptor web.xml must include the FHIR servlet and servlet-mapping. With recent Servlet specifications, you can also put a corresponding web-fragments.xml file into the classpath.
Here is an example:
<?xml version="1.0"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 3.0//EN">
<web-app>
<display-name>Test IPF IHE Web-App</display-name>
<!-- Servlet for FHIR -->
<servlet>
<servlet-name>FhirServlet</servlet-name>
<servlet-class>org.openehealth.ipf.commons.ihe.fhir.IpfFhirServlet</servlet-class>
<!-- FHIR version to be used: DSTU2_HL7ORG, DSTU3 -->
<init-param>
<param-name>fhirVersion</param-name>
<param-value>DSTU3</param-value>
</init-param>
<init-param>
<param-name>logging</param-name>
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>highlight</param-name>
<param-value>true</param-value>
</init-param>
</servlet>
<!-- Camel Endpoint Resource Mapping, should be FhirServlet -->
<servlet-mapping>
<servlet-name>FhirServlet</servlet-name>
<url-pattern>/fhir/*</url-pattern>
</servlet-mapping>
</web-app>
The following servlet init parameters are supported:
| Parameter name | Type | Default value | Short description |
|---|
| fhirVersion | FhirVersionEnum | - | which FHIR version to be used: DSTU2_HL7ORG or DSTU3 | logging | Boolean | false | writes incoming requests into the log | highlight | Boolean | false | whether responses to requests from browsers are (syntax-)highlighted | pretty | Boolean | false | whether responses are indented | pagingProviderSize | Integer | 50 | amount of paging requests being maintained concurrently | defaultPageSize | Integer | 20 | default page size of returned resources | maximumPageSize | Integer | 100 | maximum page size of returned resources
A special case is the ITI-68 transaction. This is no FHIR transaction as such but just a HTTP(S) download. Therefore, instead of being routed over the FhirServlet this transaction is served by a CamelServlet as provided by Camel’s Servlet component:
<servlet>
<servlet-name>CamelServlet</servlet-name>
<display-name>Camel Http Transport Servlet</display-name>
<servlet-class>org.apache.camel.component.servlet.CamelHttpTransportServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>CamelServlet</servlet-name>
<url-pattern>/binary/*</url-pattern>
</servlet-mapping>
The servlet definition above would match the following consumer endpoint:
from("mhd-iti68://binary[?options])
Embedded in Spring Boot
Container deployments embedded in Spring Boot can be easily achieved by depending on ipf-fhir-dstu2-spring-boot-starter or ipf-fhir-stu3-spring-boot-starter
This starter module along with camel-servlet-starter sets up the necessary servlets and the servlet init parameters are mapped to application properties.
Note that Spring Boot supports Tomcat, Jetty and Undertow as servlet implementations.