[squid-users] how to set a custom ICAP "Allow" header?

[Amos Jeffries]

On 23/03/18 03:04, claudiu.saiz wrote:
> I want to set a custom "Allow" header in ICAP OPTIONS messages, in order to
> allow Trailer support for ICAP.

That is not how protocols work. Agents advertise what features they
support and recipients can choose to use those features they understand
(or not).

No amount of forcing headers to be sent will make feature behaviours
actually happen in the proper way (quite the opposite). Nor magically
make the necessary code exist if they are not already supported.



> 
> I tried:
> 
> /acl all_requests src all
> adaptation_meta Allow "trailers" all_requests/
> 
> , but it doesn't work since "Allow" is a reserved header name.
> 
> Is there any way to do this?


Support for the still experimental ICAP Trailers feature is only
available in Squid-5. So if you require this feature you will thus be
required to run the Squid-5.0.0 alpha code at present. And it will
*only* work if the ICAP service contains matching support for the feature.
 <http://www.squid-cache.org/Versions/v5/>


HTH
Amos