Abusing Nginx Configuration To Serve And Redirect Multiple Subdomains Under a Variable Domain

gistfile1.nginxconf

# The idea is that speedtest.companyA.com can be served from the same server{} block as speedtest.companyB.com
# The index page has links to allow the user to force a connection over ipv4 or ipv6. A connection to /ipv4, for instance,
# will redirect the user to ipv4.speedtest.$X/ where $X is determined dynamically. Likewise for /ipv6, and there's /default
# to redirect to just speedtest.$X/
# Note that this does assume that "ipv4.speedtest.$X" and "ipv6.speedtest.$X" are setup with A and AAAA records respectively.

        location = /ipv4 {
                # IP access requires a hard-coded IPv4 address for the redirect.
                if ($host = "[$server_addr]") { return 302 $scheme://$ipv4addr/; }
                if ($host = "$server_addr") { return 302 $scheme://$ipv4addr/; }
                # A bare "speedtest.____" connection gets ipv4. prepended to the $host
                if ($host ~* "^speedtest") { return 302 $scheme://ipv4.$host/; }
                # A connection to our ipvX-prepended URL gets that ipvX. replaced with ipv4.
                if ($host ~* "^ipv[46].(speedtest\..+)") { return 302 $scheme://ipv4.$1/; }
                # Any unhandled patterns get bounced straight back to /
                return 302 $scheme://$host/;
        }
        location = /ipv6 {
                # IP access requires a hard-coded IPv6 address for the redirect.
                if ($host = $server_addr) { return 302 $scheme://$ipv6addr/; }
                # A bare "speedtest.____" connection gets ipv6. prepended to the $host
                if ($host ~* "^speedtest") { return 302 $scheme://ipv6.$host/; }
                # A connection to our ipvX-prepended URL gets that ipvX. replaced with ipv6.
                if ($host ~* "^ipv[46].(speedtest\..+)") { return 302 $scheme://ipv6.$1/; }
                # Any unhandled patterns get bounced straight back to /
                return 302 $scheme://$host/;
        }
        location = /default {
                if ($host ~* "^ipv[46].(speedtest\..+)") { return 302 $scheme://$1/; }
                # All unhandled patterns, including direct IP and "speedtest." just get bounced back to themselves' /
                return 302 $scheme://$host/;
        }