I had this working once.

I'm using a dynamic rewrite map to do some load balancing. Using a little perl script to call a running process manager that brings stuff up and down. Proc mgr has a simple REST interface.

apache.conf fragment

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteMap VOLLEY_BALL_SERVERS prg:/Users/todd/bin/volley
RewriteRule ^/seaside/.*$ ${VOLLEY_BALL_SERVERS:$1} [P,L]
</IfModule>

volley is a perl script - dead simple and it works fine from the command line.

#!/usr/bin/perl
$| = 1;
while (<STDIN>) {
my $cmd = $_;
open(MAP, "| curl [link|http://localhost:9550/rewriteMap?url=$cmd|http://localhost:955...writeMap?url=$cmd]");
while(<MAP>) {
print $_;
}
}

When I run volley from the cmd line, I can type urls and they get mapped like I expect.
%volley
cv
[link|http://foo/seaside/cv|http://foo/seaside/cv]
bar
[link|http://foo/seaside/bar|http://foo/seaside/bar]

When I let apache run it, it gets called, but $cmd is always empty. I can't see why that would be. Even weirder, sometimes volley gets/translates several lines of empty input for one request. Sometimes.

I'm stumped

it runs the script OK - the calls happen at the right time, but the perl script reads lines from stdin and writes responses to stdout. What gets written to stdin is empty under apache.

If it were perms, I think the script would fail to run at all.

$1 should have been $0