How Access Multiple Wordpress sites with a single login

Question

****SEE Edits below****

Edit added 1/4/2018 I started over again, following the instructions. As far as I can tell everything is correct including the synchronization plugin. fpw-sync-users.php in test.oursite.com 3 occurences of $other_prefixes = array( 'wp5l_', ); fpw-sync-users.php in forum.oursite.com 3 occurrences of $other_prefixes = array( 'wp7g_', ); Is that correct? What happens when I try to log in on either site is it just refreshes the login page and nothing happens. There are no error messages

****END EDIT****

My organization is using WordPress 4.9.1.

What we are hoping to accomplish is having members create a user profile on secure.oursite.org and when they login, they will have access to forums.oursite.org.

I have not been able to find updated instructions to complete this task. Can anyone here tell me what I need to do to accomplish this, or where to get the updated instructions?

Thank you

****ADDITIONAL Information***** I followed the instructions from @Frank P. at that link multiple times, and it is not working. I had to put everything back the way it originally was. Please see below for the steps I took and let me know if I did anything wrong.

The sites that I tried to test a Single Logon setup on are on subdomains: test.oursite.com and forum.oursite.com

test.oursite.com's database prefix is wp7g forum.oursite.com's datebase prefix is wp5l

I want test.oursite.com to be where the user is created.

1. I exported all the database tables from forum.oursite.com (except for wp5l_user and wp5l_usermeta) and imported them into the test.oursite.com datebase.

2. I went in to edit the wp-config.php files as instructed by Frank P. at this link Single sign on between two wordpress website He says both wp-config.php files must be identical, except for the prefixes at $table_prefix, which should show the original prefix of their database. Since I want the login to be created in test.oursite.com, I copied the entire wp-config.php file to forum.oursite.com's root.

3. I went in to edit forum.oursite.com's wp-config.php file and changed the $table_prefix to wp5l then saved it.

4. I went to edit wp-config.php for test.oursite.com and added the below defines and saved it.

   define('COOKIE_DOMAIN', '.test.oursite.com'); //this is where I think the problem might be define('COOKIEPATH', '/'); define('COOKIEHASH', md5('test.oursite.com')); define('CUSTOM_USER_TABLE', 'wp7g_users'); define('CUSTOM_USER_META_TABLE', 'wp7g_usermeta');

5. I copied and pasted those same defines to wp-config.php in forum.oursite.com and saved it.

6. I created the mu-plugins folder in wp-content for both test.oursite.com and forum.oursite.org

7 I created fpw-sync-users.php in the mu-plugins folder for test.oursite.com and copied Frank P's code, then changed the 3 areas to my prefix and saved it as you see below.

$other_prefixes = array(
    'wp7g_',
);

8. I created fpw-sync-users.php in the mu-plugins folder for forums.oursite.com and copied the same code from the test.oursite.com mu-plugins folder so that the prefix is wp7g as Frank said it should be. I saved it.

That was apparently the last step. I went to test.oursite.com and logged in, then went to forum.oursite.com and saw that I was not logged in there. I went to wp-login.php and tried to login with the same credentials from test.oursite.com. It did not accept those credentials. I tried to log in with the original admin credentials and it would not accept those either. So I tried again to make these custom configurations work several more times, trying different things in case I misunderstood something. Nothing is working. I am hoping someone can look over the steps I have taken and tell me what I am missing.

Thank you.

******wp-config.php for test.oursite.com*****

<?php
/**
 * The base configuration for WordPress
 *
 * The wp-config.php creation script uses this file during the
 * installation. You don't have to use the web site, you can
 * copy this file to "wp-config.php" and fill in the values.
 *
 * This file contains the following configurations:
 *
 * * MySQL settings
 * * Secret keys
 * * Database table prefix
 * * ABSPATH
 *
 * @link https://codex.wordpress.org/Editing_wp-config.php
 *
 * @package WordPress
 */

// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('DB_NAME', 'oursite_test2');


/** MySQL database username */
define('DB_USER', 'oursite_test2');


/** MySQL database password */
define('DB_PASSWORD', 'hidden');


/** MySQL hostname */
define('DB_HOST', 'localhost');


/** Database Charset to use in creating database tables. */
define('DB_CHARSET', 'hidden');


/** The Database Collate type. Don't change this if in doubt. */
define('DB_COLLATE', '');


/**#@+
 * Authentication Unique Keys and Salts.
 *
 * Change these to different unique phrases!
 * You can generate these using the {@link https://api.wordpress.org/secret-key/1.1/salt/ WordPress.org secret-key service}
 * You can change these at any point in time to invalidate all existing cookies. This will force all users to have to log in again.
 *
 * @since 2.6.0
 */

define('AUTH_KEY',hidden');

define('SECURE_AUTH_KEY',  'hidden');

define('LOGGED_IN_KEY',    'hidden');

define('NONCE_KEY',        'hidden');

define('AUTH_SALT',        'hidden');

define('SECURE_AUTH_SALT', 'hidden');

define('LOGGED_IN_SALT',   'hidden');

define('NONCE_SALT',       'hidden');


define('COOKIE_DOMAIN',         '.test.oursite.com');

define('COOKIEPATH',            '/');

define('COOKIEHASH',            md5('test.oursite.com'));


define('CUSTOM_USER_TABLE', 'wp7g_users');

define('CUSTOM_USER_META_TABLE', 'wp7g_usermeta');


/**#@-*/


/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each
 * a unique prefix. Only numbers, letters, and underscores please!
 */
$table_prefix  = 'wp7g_';


/**
 * For developers: WordPress debugging mode.
 *
 * Change this to true to enable the display of notices during development.
 * It is strongly recommended that plugin and theme developers use WP_DEBUG
 * in their development environments.
 *
 * For information on other constants that can be used for debugging,
 * visit the Codex.
 *
 * @link https://codex.wordpress.org/Debugging_in_WordPress
 */

define('WP_DEBUG', false);


/* That's all, stop editing! Happy blogging. */

/** Absolute path to the WordPress directory. */
if ( !defined('ABSPATH') )
    define('ABSPATH', dirname(__FILE__) . '/');

/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');


****wp-config.php for forum.oursite.com*****


<?php
/**
 * The base configuration for WordPress
 *
 * The wp-config.php creation script uses this file during the
 * installation. You don't have to use the web site, you can
 * copy this file to "wp-config.php" and fill in the values.
 *
 * This file contains the following configurations:
 *
 * * MySQL settings
 * * Secret keys
 * * Database table prefix
 * * ABSPATH
 *
 * @link https://codex.wordpress.org/Editing_wp-config.php
 *
 * @package WordPress
 */


// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('DB_NAME', 'oursite_test2');


/** MySQL database username */
define('DB_USER', 'oursite_test2');


/** MySQL database password */
define('DB_PASSWORD', 'hidden');


/** MySQL hostname */
define('DB_HOST', 'localhost');


/** Database Charset to use in creating database tables. */
define('DB_CHARSET', 'hidden');


/** The Database Collate type. Don't change this if in doubt. */
define('DB_COLLATE', '');


/**#@+
 * Authentication Unique Keys and Salts.
 *
 * Change these to different unique phrases!
 * You can generate these using the {@link https://api.wordpress.org/secret-key/1.1/salt/ WordPress.org secret-key service}
 * You can change these at any point in time to invalidate all existing cookies. This will force all users to have to log in again.
 *
 * @since 2.6.0
 */

define('AUTH_KEY',hidden');

define('SECURE_AUTH_KEY',  'hidden');

define('LOGGED_IN_KEY',    'hidden');

define('NONCE_KEY',        'hidden');

define('AUTH_SALT',        'hidden');

define('SECURE_AUTH_SALT', 'hidden');

define('LOGGED_IN_SALT',   'hidden');

define('NONCE_SALT',       'hidden');


define('COOKIE_DOMAIN',         '.test.oursite.com');

define('COOKIEPATH',            '/');

define('COOKIEHASH',            md5('test.oursite.com'));


define('CUSTOM_USER_TABLE', 'wp7g_users');

define('CUSTOM_USER_META_TABLE', 'wp7g_usermeta');


/**#@-*/


/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each
 * a unique prefix. Only numbers, letters, and underscores please!
 */

$table_prefix  = 'wp5l_';


/**
 * For developers: WordPress debugging mode.
 *
 * Change this to true to enable the display of notices during development.
 * It is strongly recommended that plugin and theme developers use WP_DEBUG
 * in their development environments.
 *
 * For information on other constants that can be used for debugging,
 * visit the Codex.
 *
 * @link https://codex.wordpress.org/Debugging_in_WordPress
 */

define('WP_DEBUG', false);


/* That's all, stop editing! Happy blogging. */

/** Absolute path to the WordPress directory. */

if ( !defined('ABSPATH') )
    define('ABSPATH', dirname(__FILE__) . '/');


/** Sets up WordPress vars and included files. */

require_once(ABSPATH . 'wp-settings.php');

Answer 1

In both wp-config.php files, change the following defines:

define('COOKIE_DOMAIN',         '.test.oursite.com');
define('COOKIEHASH',            md5('test.oursite.com'));

to:

define('COOKIE_DOMAIN',         '.oursite.com');
define('COOKIEHASH',            md5('oursite.com'));

Go to test.oursite.com/wp-admin/ and login as an administrator. Go to Users -> Your Profile and click on Update Profile button. Now go to forums.oursite.com/wp-admin/. You should be logged in there. If synchronization plugins in mu-plugins for both sites are correct, all is done. If they are incorrect, you'll get a message, that you don't have privileges to access this page. In that case, you'll have to correct synchronization plugins, according to my original answer. If you see login form, your wp-config.php files are not set correctly.

Answer 2

If you want to keep the websites completely separated, you can with WP Remote Users Sync (disclaimer: I am the author of the plugin)