On 12/21/2012 10:48 PM, James Pearson wrote:
In the Varnish book (and every site reposting the same example), we are shown
how to make a redirect in VCL by using 'error 750'.[1] This seems more
roundabout than necessary - why not just use 'error 302'? It'll end up being
the same to the users, but is more clear in its intention.
The only reason I can think of for not doing that is if you have any cases
where you want to display an error page with a 302 status code, but *not*
redirect. But why would you want to do that?
[1]:
https://www.varnish-software.com/static/book/VCL_functions.html#example-redirecting-users-with-vcl-error
As you can see from the example you're referring to, the error 750
defined in vcl_recv is later handled in vcl_error and "translated" to a 301.
Inside the VCL, it's often useful to define internal error codes that
may be referred to several times, and then they are picked up in
vcl_error where the error code is translated into something that the end
user (or rather the browser) understands. Error codes used for internal
handling within the VCL should not be within the numerical range where
you'd find normal error codes.
Let's say you have a lot of situations in your VCL where you need to
redirect to a login URL - then it's easy and efficient to define that
redirect *once*, label it e.g. error 751, and then return "error 751;"
where applicable in the VCL.
Of course, if you don't want or need any special handling of errors,
you're at liberty to return a regular error code whenever you want to.
--
Bjørn
_______________________________________________
varnish-misc mailing list
[email protected]
https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
