Re: how to explicitly set connection destination, i.e. different from uri authority ?

On Wed, Apr 22, 2009 at 01:01, Danny Thomas <[email protected]> wrote:
> the non-proxy path in LWP::Protocol::HTTP::request has
>  $host = $url->host;
> so it looks like the destination is always taken from the uri
> now maybe setting the proxy will do what I want, but does that
> have downsides in that the destination won't be a proxy ?

When you set the proxy then the URL passed on the request line will
differ (be a full absolute URL with scheme and everyting) so it would
not really be the same and the server will probably reject it.

I think the easiest way to fake the host that LWP actually connects to
is to override it by setting @LWP::Protocol::http::EXTRA_SOCK_OPTS
before the request is sent.  A runnable example:

  use LWP::UserAgent;
  my $ua = LWP::UserAgent->new;
  local @LWP::Protocol::http::EXTRA_SOCK_OPTS = (PeerAddr =>
"www.microsoft.com");
  my $res = $ua->get("http://localhost");
  $res->dump;

Regards,
Gisle

>
> Here's the background.
> We use a set of LWP-based scripts, each of which performs a login
> to one of our sites. The login status and time is sent to our monitoring
> system and an alert generated if the login did not behave as expected,
> or the login time was too long. This merely identifies a problem
> which could come from the web-server, application server, database,
> network etc.
>
> In one case the uri takes you directly to the page with the login form,
> but in other cases redirects, and/or cookies and/or javascript is involved.
> So I want to replace these scripts with one based on WWW::Mechanize
> which makes the code a lot simpler. Of course we still have to manually
> code for the effects of any javascript.
>
> Some of the sites to be tested are behind a load-balancer which is normally
> configured for sticky connections, i.e. connections from the testing host
> are directed to the same cluster member. We still want to test the load-
> balanced uri, in case it has problems, but it would be really good to
> individually test each cluster member.
>
> We can do that with the Blackboard servers, as they each run just one site,
> so a uri of "https://$HOSTNAME/webapps/login/" does work.
>
> However other web-servers are running multiple sites, so we want to be
> able to explicitly specify the ip-address/hostname the connection is made
> to.
>
> I believe WWW::Mechanize makes connections thru LWP::UserAgent.
> We always use https for login, but it would be good if http also worked.
>
> Is it possible to currently do what I need or would it be hard to extend
> the code to support this functionaltity ?
>
> cheers
> Danny Thomas
>
> While /etc/host entries could be used, I think that's really gross,
> particularly
> on a monitoring server which is doing a mix of tests to many hosts. You
> don't want the ping test of the load-balanced service directed to one of
> the cluster members.
>