How to extract target url from service callout policy?

[vinhpham95]

My servicecallout policy name and display name is:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ServiceCallout name="SC-Test1" enabled="true" continueOnError="false" async="false">
    <DisplayName>SC-Test1</DisplayName>

Currently, I am setting the URL as follows:

<HTTPTargetConnection>
        <Properties/>
        <URL>https://something.com/path?queryparameter=queryvalue</URL>
</HTTPTargetConnection>

Based on documentation, I see that the proper way is to do "servicecallout. {policy-name}.target.url". However, when trying to put a JS policy after my callout:

print(context.getVariable("servicecallout.SC-Test1.target.url"));

It returns null.

From the trace, I can clearly see that on the SC policy under properties, the full target URL I need is provided within the property "ServiceCallout.requesturl". However, I can't find a way to extract this property.

The closest I've been able to get is "servicecallout.requesturi" which returns "/path?queryparameter=queryvalue". However, this format isn't consistent as servicecallout.requesturl and servicecallout.targeturl both return null.

[dchiesa1]

Thanks for the question. Very clear.

I think the reason you cannot get the information you want from "servicecallout.SC-Test1.target.url" is that it was implemented as an _input_ variable, not an output variable.

Let me check to see if there is an output variable that would provide exactly the information you seek.

[dchiesa1]

Did you try reading "servicecallout.requesturi" ? (ps: case matters)

If that did not satisfy, then I think there is no variable that allows you to READ the URL that is used for the ServiceCallout.

And I think there ought to be a variable that allows that.

I'll log a feature request. For now you'll have to work around this behavior. One way to do that is to configure the SC policy to use a variable in the URL.

<HTTPTargetConnection>
        <Properties/>
        <URL>{my_sc_url}</URL>
</HTTPTargetConnection>

That might not exactly work. You might need to do this:

<HTTPTargetConnection>
        <Properties/>
        <URL>https://{my_sc_host}{my_sc_path}</URL>
</HTTPTargetConnection>

And... THEN read servicecallout.POLICYNAME.target.url

[dchiesa1]

I have one followup question though: why do you need to read the URL in the proxy flow? The URL is hard-coded there in the <URL> element.

[vinhpham95]

Thanks for commenting, Dino. Essentially, I am using a complex shared flow operates logic on a set of information (service call out target URL being one of them). Hence, I need to make it generalized such that I can extract it as a variable rather hard-coding. The case above where I hard-code the URL is really for testing purposes. However in production we are expected to avoid the hard-coding and the target URL will actually be invisible to us.

[dchiesa1]

OK I understand. And can you try it that way? Can you try it, with the URL "not hard coded"? The code path in the gateway is different, depending on whether you use a hardcoded url or a message template as

<URL>https://{sc_target_host}{sc_target_path}</URL>

When you do that ^^, the target.url variable is written, and you can later read it. I believe that may solve your problem.

[#7]

You can get the target url as below

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ServiceCallout async="false" continueOnError="false" enabled="true" name="Service-Callout-1">
    <DisplayName>Service Callout-1</DisplayName>
    <Properties/>
    <Request clearPayload="true" variable="myreq">
        <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
    </Request>
    <Response>calloutResponse</Response>
    <HTTPTargetConnection>
        <Properties>
            <Property name="io.timeout.millis">20000</Property>
        </Properties>
        <URL>https://api.github.com/users</URL>
    </HTTPTargetConnection>
</ServiceCallout>

myreq.url = https://api.github.com/users

print(context.getVariable("myreq.url"));