Update a specific site from 'http://' to 'https://'.

http-to-https.php

<?php
/**
 * Update a specific site from 'http://' to 'https://'.
 *
 * Only touches the 'home' and 'siteurl' options.
 * Depending on plugins, etc., you may need to update other options too.
 *
 * Run on WordPress multisite with:
 *
 * wp site list --field=url | xargs -I % wp eval-file http-to-https.php --url=%
 */

foreach ( array( 'home', 'siteurl' ) as $option ) {
	$existing = get_option( $option );
	$new = str_replace( 'http://', 'https://', $existing );
	if ( update_option( $option, $new ) ) {
		WP_CLI::log( "Updated '{$option}' to '{$new}'" );
	} else {
		WP_CLI::log( "Didn't update '{$option}' to '{$new}'" );
	}
}
WP_CLI::success( 'Options updated for ' . home_url() );