Assign a value read from KVM to a header name

Google Cloud Apigee
1

Hi Apigee Community,

I’m successfully reading values from the KVMs (using standard Key Value Maps Operations Policy)**. Then I’m using these values to create customised error messages with Assign Message Policy. Everything works fine except when I try to replace the name value of the header with a name retrieved from a KVM.

My question: Is it possible to assign a header name value instead of just typing it in?

Ex. to somehow have this (in the example below, header value is read correctly, while header name is read as a string “errorMessage.headerName”):

<Headers>
            <Header name="{errorMessage.headerName}">{errorMessage.headerValue}</Header>
</Headers>

Instead of:

<Headers>
            <Header name="headerName">{errorMessage.headerValue}</Header>
</Headers>

Thanks in advance for any help you might provide,

Ula

2

Great Question @Ula ,

As far as I know, not every place Apigee policies support dynamic variables. Yep, It’s strange. I believe that’s the way system is designed as of today. I have posted a similar question in community sometime back that you can find here.

Coming to your question, I don’t think AssignMessagepolicy supports dynamic header naming. As a workaround, you can use a javascript policy with code like below,

var headerName = context.getVariable("errorMessage.headerName");

context.setVariable('request.header.' + headerName, context.getVariable("errorMessage.headerValue"));

Hope it helps.

3

@Anil Sagar, thanks a lot for your answer! It’s indeed very strange, but definitely good to know. I wonder whether there are any plans to improve it in the future…

4

@Ula , Glad it’s helpful. Yep, We will keep you posted if any updates related to same in future.

5

@Anil Sagar Has there been any update on this? I checked the documentation and I couldn’t still find a way to achieve this without using a JS policy.