Multisite Network Port Num Issues?

Question

I am following This tutorial to Create a Network of WordPress Sites . After adding

/* Multisite */
define( 'WP_ALLOW_MULTISITE', true ); 

to my wp-config.php file and when I start to configure multisite network I got this error

ERROR: You cannot install a network of sites with your server address.
You cannot use port numbers such as :8080

I try to change

 Listen 0.0.0.0:8080
Listen [::0]:8080  

to

 Listen 0.0.0.0:80
Listen [::0]:80

from httpd.conf of Apache but due to this wamp server remains orange . How to solve this .I am a new to WordPress Any help would be highly appreciated .

Answer 1

Update: Finally supported in WP 6.6. The core ticket here was recently merged in and closed.

Older answer:

Warning: This is just a test for dev installs and not production sites

I was curious to see if there was a workaround, for those who want to develope multisites on their dev installs but on different ports than :80 and :443, e.g. :8080.

I only found this blog post by Henri Benoit. There he gives examples how to modify the 3.9.1 core, to get around the core restrictions.

Here's a must-use plugin /wp-content/mu-plugins/wpse-ms-on-different-port.php where we try to avoid core modifications:

<?php 
/**
 * Test for multisite support on a different port than :80 and :443 (e.g. :8080)
 *
 * Here we assume that the 'siteurl' and 'home' options contain the :8080 port
 *
 * WARNING: Not suited for production sites!
 */

/**
 * Get around the problem with wpmu_create_blog() where sanitize_user()  
 * strips out the semicolon (:) in the $domain string
 * This means created sites with hostnames of 
 * e.g. example.tld8080 instead of example.tld:8080
 */
add_filter( 'sanitize_user', function( $username, $raw_username, $strict )
{
    // Edit the port to your needs
    $port = 8080;

    if(    $strict                                                // wpmu_create_blog uses strict mode
        && is_multisite()                                         // multisite check
        && $port == parse_url( $raw_username, PHP_URL_PORT )      // raw domain has port 
        && false === strpos( $username, ':' . $port )             // stripped domain is without correct port
    )
        $username = str_replace( $port, ':' . $port, $username ); // replace e.g. example.tld8080 to example.tld:8080

    return $username;
}, 1, 3 );

/**
 * Temporarly change the port (e.g. :8080 ) to :80 to get around 
 * the core restriction in the network.php page.
 */
add_action( 'load-network.php', function()
{
    add_filter( 'option_active_plugins', function( $value )
    {
        add_filter( 'option_siteurl', function( $value )
        {
            // Edit the port to your needs
            $port = 8080;

            // Network step 2
            if( is_multisite() || network_domain_check() )
                return $value;

            // Network step 1
            static $count = 0;
            if( 0 === $count++ )
                $value = str_replace( ':' . $port, ':80', $value );
            return $value;
        } );
        return $value;
    } );
} );

I just tested this on my dev install, but this might need more checks of course ;-)

Answer 2

You can't use port 8080. I have no idea why as that is a fairly common port for a web server. However, you can't:

121         if ( ( false !== $has_ports && ! in_array( $has_ports, array( ':80', ':443' ) ) ) ) {
122                 echo '<div class="error"><p><strong>' . __( 'ERROR:') . '</strong> ' . __( 'You cannot install a network of sites with your server address.' ) . '</p></div>';
123                 echo '<p>' . sprintf(
124                         /* translators: %s: port number */
125                         __( 'You cannot use port numbers such as %s.' ),
126                         '<code>' . $has_ports . '</code>'
127                 ) . '</p>';
128                 echo '<a href="' . esc_url( admin_url() ) . '">' . __( 'Return to Dashboard' ) . '</a>';
129                 echo '</div>';
130                 include( ABSPATH . 'wp-admin/admin-footer.php' );
131                 die();
132         }

Notice ! in_array( $has_ports, array( ':80', ':443' ) ). Those ports are hard-coded. There are no filters you can use to alter them, not even in get_clean_basename() (and I am afraid to guess at what horrors you'd create if you could alter what that returns).

Alter your server to use port 443 or port 80 instead.