¿why does my service callout not work?

[apiguru]

I'm trying to call an another service internally using proxy chain. the intermediate service receives the call but not the URI. When I look at the policy in trace I see the complete URI.

Here's what I'm doing in last 2 steps

<AssignMessage name="Verify_Request">
    <DisplayName>Verify_Request</DisplayName>
    <Properties/>
    <Set>
        <Verb>GET</Verb>
        <Path>/abc/bbc/api/def</Path>
    </Set>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <AssignTo createNew="false" transport="http" type="request"/>
</AssignMessage>

<ServiceCallout  name="SC-verify">
    <Request clearPayload="true">
        <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
    </Request>
    <Response>calloutResponse</Response>
    <LocalTargetConnection>
        <APIProxy>VerificationProxy</APIProxy>
        <ProxyEndpoint>default</ProxyEndpoint>
    </LocalTargetConnection>
</ServiceCallout>

[dchiesa1]

If you want the ServiceCallout policy to reference a particular request object, you must create a new one with AssignMessage. That means

<AssignTo 
   createNew="true" 
   transport="http" 
   type="request">my_sc_request</AssignTo>

Also you need to then reference that request in the ServiceCallout policy. like this

  <Request clearPayload="false" variable="my_sc_message"/>

Putting it together, ...

AssignMessage

<AssignMessage name="AM-Verify-Request">
    <Set>
        <Verb>GET</Verb>
        <Path>/abc/bbc/api/def</Path>
    </Set>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <AssignTo createNew="true" transport="http" type="request">verifyRequest</AssignTo>
</AssignMessage>

ServiceCallout

<ServiceCallout  name="SC-verify">
    <Request clearPayload="false" variable="verifyRequest"/>
    <Response>calloutResponse</Response>
    <LocalTargetConnection>
        <APIProxy>VerificationProxy</APIProxy>
        <ProxyEndpoint>default</ProxyEndpoint>
    </LocalTargetConnection>
</ServiceCallout>

I suggest that you follow a naming convention for your policies. SC => ServiceCallout, and AM=> AssignMessage. And similarly for RaiseFault, KeyValueMapOperations, and etc.