README.adoc

Spring Boot Example with Camel Platform HTTP act as reverse proxy

Introduction

This example illustrates how to use Spring Boot with Camel. It implements a reverse proxy using platform-http.

The project uses camel-platform-http-starter component as the implementation for platform-http-engine and camel-http-starter to implement the producer calling the http endpoint.

Run

You can run this example using:

mvn spring-boot:run

After the Spring Boot application is started, you can execute the following HTTP requests:

curl --proxy http://localhost:8080 -L  http://httpbin.org/get?arg1=val1 -H  'accept: application/json'

The command will call a test endpoint using the application as reverse proxy, you should see the Camel headers from both request and response in the log. Something similar to:

INFO 70370 --- [ad #1 - WireTap] header-request                           : {accept=application/json, arg1=val1, CamelHttpCharacterEncoding=UTF-8, CamelHttpMethod=GET, CamelHttpPath=/get, CamelHttpQuery=arg1=val1, CamelHttpServletRequest=org.apache.catalina.connector.RequestFacade@4f31b074, CamelHttpServletResponse=org.springframework.web.context.request.async.StandardServletAsyncWebRequest$LifecycleHttpServletResponse@158137c0, CamelHttpUri=/get, CamelHttpUrl=http://httpbin.org/get, CamelPlatformHttpContextPath=/, host=httpbin.org, proxy-connection=Keep-Alive, user-agent=curl/8.9.1}
INFO 70370 --- [ad #2 - WireTap] header-response                          : {accept=application/json, Access-Control-Allow-Credentials=true, Access-Control-Allow-Origin=*, arg1=val1, CamelHttpCharacterEncoding=UTF-8, CamelHttpMethod=GET, CamelHttpQuery=arg1=val1, CamelHttpResponseCode=200, CamelHttpResponseText=OK, CamelHttpServletRequest=org.apache.catalina.connector.RequestFacade@4f31b074, CamelHttpServletResponse=org.springframework.web.context.request.async.StandardServletAsyncWebRequest$LifecycleHttpServletResponse@158137c0, CamelHttpUri=/get, CamelHttpUrl=http://httpbin.org/get, CamelPlatformHttpContextPath=/, Connection=keep-alive, Content-Length=387, Content-Type=application/json, Date=Thu, 04 Sep 2025 11:59:30 GMT, proxy-connection=Keep-Alive, Server=gunicorn/19.9.0}

The Spring Boot application can be stopped pressing [CTRL] + [C] in the shell.

Deploy on OpenShift

Make sure you can access to a namespace on an OpenShift cluster, then run

mvn install -P openshift

In OpenShift, an Ingress resource is used instead of a Route when the application requires the original Host header to be preserved. This is because OpenShift Routes rely on header-based routing, which can modify the Host header, making them unsuitable for scenarios where the backend depends on the original value. To support this behavior, a specific Ingress is configured to forward requests to the appropriate backend based on the requested host. If additional backend endpoints need to be exposed through the proxy, corresponding Ingress rules must be defined accordingly; it is also possible to set host using wildcards.

Once the POD is ready you can call the application using the exposed ingress at

curl --proxy http://$(oc get ingress camel-example-spring-boot-platform-http-proxy -o go-template --template='{{(index .status.loadBalancer.ingress 0).hostname}}'):80 -L  http://httpbin.org/get?arg1=val1 -H  'accept: application/json'

you can see the log at

oc logs deployment/camel-example-spring-boot-platform-http-proxy

Help and contributions

If you hit any problem using Camel or have some feedback, then please let us know.

We also love contributors, so get involved :-)

The Camel riders!