How to Migrate Wordpress Website from 32-bit CentOS Linux 6.3 to 64-bit CentOS Linux 8.2 (2004)

Subject: How to Migrate Wordpress Website from 32-bit CentOS Linux 6.3 to 64-bit CentOS Linux 8.2 (2004)

Author of this Guide: Mr. Turritopsis Dohrnii Teo En Ming (TARGETED INDIVIDUAL)

Country: Singapore

Date: 31 August 2020 Monday Singapore Time

Type of Publication: Plain Text

Document Version: 20200831.01

SECTION 1 Information Gathering Stage
=====================================

Host operating system is Windows Server 2008 R2 Standard

Host Processor: Intel Xeon CPU E5620 @ 2.40 GHz

Host Memory: 24 GB RAM

Old Oracle VirtualBox version is 4.1.18

Upgrade to Virtualbox version 6.1.12 (COMPLETED SUCCESSFULLY AFTER RESTARTING WINDOWS SERVER)

Old CentOS Linux VM is version 6.3 (32-bit only)

Old Apache web server version 2.2.15

Old MySQL database server version 5.1.61

Old PHP version 5.6.40

Interface eth0: AAA.BBB.CCC.3/24 (ifconfig)
Gateway: AAA.BBB.CCC.2 (ip route) (Gateway is the next hop router which is also the Fortigate firewall)
/etc/resolv.conf (for DNS Client):
nameserver AAA.BBB.CCC.1 (This is the Windows Server with DNS Server role installed)

How to login to OLD MySQL database server:

mysql -u root -p

Old hostname: centos63.teo-en-ming-corp.com

Old Virtual Machine Settings
============================

4 GB RAM, 2 processors, 20 GB storage, network adapter: bridged to broadcom bcm5709c

NEW Virtual Machine Settings
============================

4 GB RAM, 4 processors, 100 GB storage, network adapter: bridged to broadcom bcm5709c

After using Advanced IP scanner and checking DHCP scope in Microsoft DHCP server in Windows Server,

Unused IP address: AAA.BBB.CCC.4 (Use this IP address for new CentOS 8.2 Linux VM)

SECTION 2 Installation of NEW CentOS 8.2 Linux Virtual Machine
==============================================================

New Hostname: centos82.teo-en-ming-corp.com

NEW IP: AAA.BBB.CCC.4
Subnet mask: 255.255.255.0 (Class C)
Gateway: AAA.BBB.CCC.2
DNS1: 8.8.8.8

Problem
=======

CentOS 8.2 Linux 64-bit will not start and run because VirtualBox is too old (version 4.1.18). Intel Virtualization and VT-d already enabled in server BIOS previously.
So running 64-bit virtual machines is not an issue.

Solution
========

After upgrading to VirtualBox 6.1.12, CentOS 8.2 Linux 64-bit is able to start and run.

SECTION 3 Generate a Backup of ALL Databases in the Old VM
===========================================================

Reference Guide: How to backup and restore MySQL databases using the mysqldump command

Link: https://www.sqlshack.com/how-to-backup-and-restore-mysql-databases-using-the-mysqldump-command/

Reference Guide: How to Show Users in MySQL using Linux

Link: https://www.hostinger.com/tutorials/mysql-show-users/

# cd /root

# mysqldump -u root -p --all-databases > all-databases-20200829.sql

# du -h all-databases-20200829.sql

70M all-databases-20200829.sql

SECTION 4 Disable SELinux (Security Enhanced Linux)
===================================================

You MUST disable SELinux, otherwise Apache web server will not work.

If you DO NOT want to disable SELinux, you must be an expert in SELinux to configure SELinux.

# nano /etc/selinux/config

SELINUX=disabled

# reboot

SECTION 5 Disable firewalld Software Firewall
=============================================

Because already protected by Fortigate firewall at the perimeter.

# systemctl disable firewalld

# reboot

SECTION 6 LAMP (Linux, Apache, MySQL and PHP) Installation
==========================================================

I will be installing Apache web server 2.4.37-21, MariaDB server 3:10.3.17-1, PHP 7.2.24-1 and OpenSSL 1:1.1.1c-15 in 64-bit CentOS Linux 8.2 (2004).

Sub-Section on Installing Apache Web Server
===========================================

# dnf install php php-fpm php-gd

You *MUST* install php-gd, otherwise Apache Web Server cannot execute PHP scripts.

# dnf install httpd

# systemctl enable httpd

# systemctl start httpd

[root@centos82 ~]# ps -ef | grep httpd
root       33214       1  0 22:03 ?        00:00:00 /usr/sbin/httpd -DFOREGROUND
apache     33351   33214  0 22:03 ?        00:00:00 /usr/sbin/httpd -DFOREGROUND
apache     33352   33214  1 22:03 ?        00:00:00 /usr/sbin/httpd -DFOREGROUND
apache     33355   33214  1 22:03 ?        00:00:00 /usr/sbin/httpd -DFOREGROUND
apache     33357   33214  0 22:03 ?        00:00:00 /usr/sbin/httpd -DFOREGROUND
root       36374    7368  0 22:03 pts/0    00:00:00 grep --color=auto httpd

On the OLD CentOS 6.3 server:

# cd /etc/httpd

# tar cfvz apacheconf.tar.gz conf conf.d

# mv apacheconf.tar.gz /root

On the NEW CentOS 8.2 server:

# cd /etc/httpd

# cp -r conf conf.original

# cp -r conf.d conf.d.original

# scp root@AAA.BBB.CCC.3:/root/apacheconf.tar.gz .

# tar xfvz apacheconf.tar.gz

On the OLD CentOS 6.3 server:

# cd /var/www/html

# tar cfvz websites.tar.gz *

(1.4 GB)

On the NEW CentOS 8.2 server:

# cd /var/www/html

# scp root@AAA.BBB.CCC.3:/root/websites.tar.gz .

# tar xfvz websites.tar.gz

Continuing on the NEW CentOS 8.2 server
=======================================

How to troubleshoot Apache web server
=====================================

The following are TWO very important Linux troubleshooting commands.

# systemctl status httpd (check the error Apache web server gives out)

# httpd -t (for checking Apache web server configuration syntax)

Make the following changes to /etc/httpd/conf/httpd.conf, as follows:

Rationale for unloading modules here: The modules were already loaded in config files in another location /etc/httpd/conf.modules.d, so we disable in httpd.conf to avoid duplication.
If there are duplication for loading modules, Apache web server cannot start.

#
# Dynamic Shared Object (DSO) Support
#
# To be able to use the functionality of a module which was built as a DSO you
# have to place corresponding `LoadModule' lines at this location so the
# directives contained in it are actually available _before_ they are used.
# Statically compiled modules (those listed by `httpd -l') do not need
# to be loaded here.
#
# Example:
# LoadModule foo_module modules/mod_foo.so
#
#LoadModule auth_basic_module modules/mod_auth_basic.so
#LoadModule auth_digest_module modules/mod_auth_digest.so
#LoadModule authn_file_module modules/mod_authn_file.so
#LoadModule authn_alias_module modules/mod_authn_alias.so
#LoadModule authn_anon_module modules/mod_authn_anon.so
#LoadModule authn_dbm_module modules/mod_authn_dbm.so
#LoadModule authn_default_module modules/mod_authn_default.so
#LoadModule authz_host_module modules/mod_authz_host.so
#LoadModule authz_user_module modules/mod_authz_user.so
#LoadModule authz_owner_module modules/mod_authz_owner.so
#LoadModule authz_groupfile_module modules/mod_authz_groupfile.so
#LoadModule authz_dbm_module modules/mod_authz_dbm.so
#LoadModule authz_default_module modules/mod_authz_default.so
#LoadModule ldap_module modules/mod_ldap.so
#LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
#LoadModule include_module modules/mod_include.so
#LoadModule log_config_module modules/mod_log_config.so
#LoadModule logio_module modules/mod_logio.so
#LoadModule env_module modules/mod_env.so
#LoadModule ext_filter_module modules/mod_ext_filter.so
#LoadModule mime_magic_module modules/mod_mime_magic.so
#LoadModule expires_module modules/mod_expires.so
#LoadModule deflate_module modules/mod_deflate.so
#LoadModule headers_module modules/mod_headers.so
LoadModule usertrack_module modules/mod_usertrack.so
#LoadModule setenvif_module modules/mod_setenvif.so
#LoadModule mime_module modules/mod_mime.so
#LoadModule dav_module modules/mod_dav.so
#LoadModule status_module modules/mod_status.so
#LoadModule autoindex_module modules/mod_autoindex.so
#LoadModule info_module modules/mod_info.so
#LoadModule dav_fs_module modules/mod_dav_fs.so
#LoadModule vhost_alias_module modules/mod_vhost_alias.so
#LoadModule negotiation_module modules/mod_negotiation.so
#LoadModule dir_module modules/mod_dir.so
#LoadModule actions_module modules/mod_actions.so
LoadModule speling_module modules/mod_speling.so
#LoadModule userdir_module modules/mod_userdir.so
#LoadModule alias_module modules/mod_alias.so
#LoadModule substitute_module modules/mod_substitute.so
#LoadModule rewrite_module modules/mod_rewrite.so
#LoadModule proxy_module modules/mod_proxy.so
#LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
#LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
#LoadModule proxy_http_module modules/mod_proxy_http.so
#LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
#LoadModule proxy_connect_module modules/mod_proxy_connect.so
#LoadModule cache_module modules/mod_cache.so
#LoadModule suexec_module modules/mod_suexec.so
#LoadModule disk_cache_module modules/mod_disk_cache.so
LoadModule cgi_module modules/mod_cgi.so
#LoadModule version_module modules/mod_version.so

IncludeOptional conf.d/*.conf (Notice the use of OPTIONAL)
Include conf.modules.d/*.conf (DEFAULT CONFIG FILES INSTALLED BY APACHE WEB SERVER 2.4.37)

Install the Secure Sockets Layer (SSL) module for Apache web server

# dnf install mod_ssl

Make the following changes to /etc/httpd/conf.d/ssl.conf, as follows:

#SSLMutex default (MUST be disabled)

Transferring Public Key from OLD server to NEW server:

# cd /etc/pki/tls/certs

# scp root@AAA.BBB.CCC.3:/root/teo-en-ming-corp.crt .

Transferring Private Key from OLD server to NEW server:

# cd /etc/pki/tls/private/

# scp root@AAA.BBB.CCC.3:/root/teo-en-ming-corp.key .

Install Python3 module for Apache web server:

# dnf install python3-mod_wsgi

Make the following changes to /etc/httpd/conf.d/wsgi.conf, as follows:

LoadModule wsgi_module modules/mod_wsgi_python3.so

Install the Perl module:

# dnf install epel-release

# dnf install mod_perl

Make the following changes to /etc/httpd/conf.d/perl.conf, as follows:

#LoadModule perl_module modules/mod_perl.so

Because Perl module is already loaded in /etc/httpd/conf.modules.d/

Disable SSL virtual hosts for now (Our server will support only http and no https at the moment)

# cd /etc/httpd/conf.modules.d/

# mv 00-ssl.conf 00-ssl.conf.original

# cd /etc/httpd/conf.d

# mv ssl.conf ssl.conf.1

Sub-Section on Installing MariaDB (MySQL) Database Server
=========================================================

# dnf install mariadb-server

# systemctl enable mariadb

# systemctl start mariadb

Reference Guide: How to Use SCP Command to Securely Transfer Files
Link: https://linuxize.com/post/how-to-use-scp-command-to-securely-transfer-files/

Transfer backup of ALL databases from OLD server to NEW server:

# scp root@AAA.BBB.CCC.3:/root/all-databases-20200829.sql .

Restore ALL databases on NEW server:

# mysql < all-databases-20200829.sql

Login to MySQL (MariaDB):

# mysql

Check all MySQL users are imported:

MariaDB [(none)]> select user from mysql.user;
+------------------+
| user             |
+------------------+
| root             |
|                  |
| root             |
|                  |
| root             |
| aaa              |
| bbb              |
| ccc              |
+------------------+
8 rows in set (0.001 sec)

Sub-Section on Installing PHP 7.2
=================================

We WON'T be using PHP configuration from OLD CentOS 6.3 server:

# /etc/httpd/conf.d

# mv php.conf php.conf.63

Use the PHP configuration on NEW CentOS 8.2 server:

# cp php.conf.rpmnew php.conf

ERROR ENCOUNTERED
=================

ERROR: Your PHP installation appears to be missing the MySQL extension which is required by WordPress

Solution is found at: https://www.howtoforge.com/tutorial/centos-lamp-server-apache-mysql-php/

SOLUTION
========

MUST install php-mysqlnd

# dnf install php-mysqlnd

SECTION 7 Apache Web Server Virtual Hosts
=========================================

/etc/httpd/conf/httpd.conf

### Section 3: Virtual Hosts
#
# VirtualHost: If you want to maintain multiple domains/hostnames on your
# machine you can setup VirtualHost containers for them. Most configurations
# use only name-based virtual hosts so the server doesn't need to worry about
# IP addresses. This is indicated by the asterisks in the directives below.
#
# Please see the documentation at
# <URL:http://httpd.apache.org/docs/2.2/vhosts/>
# for further details before you try to setup virtual hosts.
#
# You may use the command line option '-S' to verify your virtual host
# configuration.

#
# Use name-based virtual hosting.
#
#NameVirtualHost *:80
#
# NOTE: NameVirtualHost cannot be used without a port specifier
# (e.g. :80) if mod_ssl is being used, due to the nature of the
# SSL protocol.
#

#
# VirtualHost example:
# Almost any Apache directive may go into a VirtualHost container.
# The first VirtualHost section is used for requests without a known
# server name.
#
#<VirtualHost *:80>
#    ServerAdmin webmaster@dummy-host.example.com
#    DocumentRoot /www/docs/dummy-host.example.com
#    ServerName dummy-host.example.com
#    ErrorLog logs/dummy-host.example.com-error_log
#    CustomLog logs/dummy-host.example.com-access_log common
#</VirtualHost>


#NameVirtualHost *:80

<VirtualHost *:80>
    ServerAdmin ceo@teo-en-ming-corp.com
    DocumentRoot /var/www/html/Teo-En-Ming-Corp
    ServerName teo-en-ming-corp.com
    redirect permanent / http://www.teo-en-ming-corp.com
</VirtualHost>

<VirtualHost *:80>
    ServerAdmin ceo@teo-en-ming-corp.com
    DocumentRoot /var/www/html/Teo-En-Ming-Corp
    ServerName www.teo-en-ming-corp.com

    RewriteEngine off
<Directory /var/www/html/Teo-En-Ming-Corp/>
        AllowOverride All
</Directory>

    <Location />
        RewriteEngine on
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule !\.(js|ico|gif|jpg|png|css)$ /index.php
    </Location>
</VirtualHost>

<VirtualHost *:80>
    ServerAdmin ceo@teo-en-ming-corp.com
    DocumentRoot /var/www/html/DonaldTrump
    ServerName donaldtrump.com.sg
    redirect permanent / http://www.donaldtrump.com.sg
</VirtualHost>

<VirtualHost *:80>
    ServerAdmin ceo@teo-en-ming-corp.com
    DocumentRoot /var/www/html/DonaldTrump
    ServerName www.donaldtrump.com.sg

    RewriteEngine off

    <Location />
        RewriteEngine on
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule !\.(js|ico|gif|jpg|png|css)$ /index.php
    </Location>
</VirtualHost>

#<VirtualHost *:80>
#    ServerAdmin ceo@teo-en-ming-corp.com
#    DocumentRoot /var/webmiln
#    ServerName centos.teo-en-ming-corp.com
#    redirect permanent / https://centos.teo-en-ming-corp.com:10000
#</VirtualHost>

<VirtualHost *:80>
    ServerAdmin ceo@teo-en-ming-corp.com
    DocumentRoot /var/www/html/Teo-En-Ming-Corp_old
    ServerName old.teo-en-ming-corp.com

    RewriteEngine off

    <Location />
        RewriteEngine on
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule !\.(js|ico|gif|jpg|png|css)$ /index.php
    </Location>
</VirtualHost>

SECTION 8 .htaccess
===================

/var/www/html/Teo-En-Ming-Corp/wp-admin/.htaccess:

order deny,allow
deny from all
allow from AAA.BBB.CCC.DDD
allow from AAA.BBB.CCC.DDD
allow from AAA.BBB.CCC.DDD
allow from AAA.BBB.CCC.DDD
allow from AAA.BBB.CCC.DDD

SECTION 9 FORTIGATE FIREWALL (STATIC NAT/PORT FORWARDING CONFIGURATION)
=======================================================================

Create Virtual IPs for Static NAT/port forwarding.

Edit Virtual IP
===============

Name: Wordpress-Website

Interface: Internet (wan1)

Type: Static NAT

External IP Address/Range: AAA.BBB.CCC.DDD - AAA.BBB.CCC.DDD

Mapped IP Address/Range: AAA.BBB.CCC.4 - AAA.BBB.CCC.4

Optional Filters: No

Port Forwarding: No

Click OK.

Then create IPv4 firewall polic(ies) from WAN1 to Internal using the created Virtual IP, allowing http, https, icmp, ssh, and/or other networking protocols as you wish.

You may also use Security Profiles in Fortigate firewall as you wish:

Antivirus

Web Filter

DNS Filter

Application Control

FortiClient Compliance

SSL/SSH Inspection

Web Rating Overrides

Custom Signatures





REFERENCES
==========

[1] https://lkml.org/lkml/2020/8/31/454

[2] http://lkml.iu.edu/hypermail/linux/kernel/2008.3/09047.html

[3] https://marc.info/?l=linux-kernel&m=159888024529073&w=2

[4] https://lwn.net/ml/linux-kernel/70ce3070fa816dbbe2e6424b2ae7f322%40teo-en-ming.com/

[5] http://lists.linuxfromscratch.org/pipermail/lfs-chat/2020-August/029149.html

[6] https://lists.centos.org/pipermail/centos/2020-August/351448.html

[7] https://marc.info/?l=apache-httpd-users&m=159888114229385&w=2

[8] https://lists.launchpad.net/maria-discuss/msg05917.html

[9] https://marc.info/?l=php-general&m=159888203429670&w=2

[10] https://mta.openssl.org/pipermail/openssl-users/2020-August/012915.html