In /etc/httpd.conf:

    server "www.example.com" {
            listen on * port 80
            root "/htdocs/perl"
            location "*.pl" {  
                    fastcgi
            }
            location "/.well-known/acme-challenge/*" {
                    root "/acme"
                    request strip 2
            }
    }


To figure out what files need to be copied into the chroot:

$ ldd /usr/bin/perl

/usr/bin/perl:

        Start            End              Type  Open Ref GrpRef Name

        0000022622dc8000 0000022622dcd000 exe   1    0   0      /usr/bin/perl

        000002285bdc7000 000002285c133000 rlib  0    1   0      /usr/lib/libperl.so.20.0

        00000228c7de6000 00000228c7e16000 rlib  0    2   0      /usr/lib/libm.so.10.1

        000002282f00d000 000002282f101000 rlib  0    2   0      /usr/lib/libc.so.96.0

        0000022914fb2000 0000022914fb2000 ld.so 0    1   0      /usr/libexec/ld.so



So I start with this initial guess to build the chroot. I run the following as root:

    mkdir -p /var/www/usr/{bin,lib,libexec}
    cp /usr/bin/perl /var/www/usr/bin/
    cp -p /usr/lib/lib{c,m,perl}.so* /var/www/usr/lib/
    cp /usr/libexec/ld.so /var/www/usr/libexec/


We need to turn on slowcgi:

    $ doas rcctl enable slowcgi
    $ doas rcctl start slowcgi


Then we run:

$ doas chroot -u www -g daemon /var/www perl

I test some random gibberish to make sure perl works inside the chroot:

    print "shibboleth";


Then ctrl+d to escape; and since it echoes `shibboleth`, it works.

Next, I create the directory to hold perl scripts:

    mkdir -p /var/www/htdocs/perl/


Now I put an index.pl in /var/www/htdocs/perl/ just to see if the web server loads it:

    #!/usr/bin/perl -w
    use strict;
    print "Content-Type:text/html\n\n";
    print "This is the index file for www.example.com\n";


Make sure to set the proper permissions:

    $ doas chown -R www:daemon /var/www/htdocs/perl/
    $ doas chmod +x /var/www/htdocs/perl/index.pl


At this point I try running this command:

    $ curl example.com/index.pl


I get a 500 Internal Error, which means perl is not able to execute properly.

So I search for missing perl libraries:

    $ doas find / -iname '*perl*'


The interesting one is the folder /usr/libdata/perl5 . We definitely need these libraries, so I update my script for creating the chroot:

    mkdir -p /var/www/usr/{bin,lib,libexec,libdata}
    cp /usr/bin/perl /var/www/usr/bin/
    cp -p /usr/lib/lib{c,m,perl,pthread,util,z}.so* /var/www/usr/lib/
    cp /usr/libexec/ld.so /var/www/usr/libexec/
    cp -R /usr/libdata/perl5 /var/www/usr/libdata/
    mkdir -p /var/www/{tmp,dev}
    chown www:daemon /var/www/tmp
    touch /var/www/dev/null