WSO2: Avoid hard-coding URI ports in Address Endpoint - wso2

Question

I have configured an offset of '10' to my ESB server on the carbon.xml file. Now all deployed API's are pointing to the port 8290.
In my API I am calling another API via an Http Endpoint. I am setting the URI template manually to: http://localhost:8290/paramAPI, as follows:
<send>
<endpoint>
<http method="get" uri-template="http://localhost:8290/paramAPI"/>
</endpoint>
</send>
However I also want to deploy to other server instances. For example, I would like to deploy to a server with an offset of '20', and therefore the '/paramAPI' would no longer be reachable at port '8290', instead on '8300'.
In this case, the Http endpoint inside the send mediator must become:
<send>
<endpoint>
<http method="get" uri-template="http://localhost:8300/paramAPI"/>
</endpoint>
</send>
I am searching for a method to parameterize the port value.
I have tried to use local entries by defining a string variable on the server by the name APIPort. When referencing it, I modified the HTTP endpoint as follows:
<send>
<endpoint>
<http method="get" uri-template="http://localhost:{APIPort}/paramAPI"/>
</endpoint>
</send>
but I got: java.net.MalformedURLException: For input string: "{APIPort}"
What is the best approach to parameterize URI's? if local entries are used then what is the proper way to use them as parameters and reference them in the URI?
Much appreciated and kind regards,

Answer 1

if I recall correctly you should use uri.var for your uri-template properties. Try to name your property uri.var.APIPort instead.
To be sure I created a simple API , see the following example:
<api xmlns="http://ws.apache.org/ns/synapse" name="testapi" context="/test" version="1" version-type="context">
<resource methods="POST GET">
<inSequence>
<property name="uri.var.version" value="v2"/>
<send>
<endpoint>
<http uri-template="http://mocky.io/{uri.var.version}/5d1dec2a3000006a00d7239d"/>
</endpoint>
</send>
</inSequence>
<outSequence>
<send/>
</outSequence>
</resource>
</api>