Linux (Ubuntu) Installation - Supporting Software - 18.04

From IHRIS Wiki

This document describes the needed installation and configuration of supporting software for iHRIS on Ubuntu 16.04 LTS, Xenial Xerus. This will only work with iHRIS 4.3 or greater (or additional local changes). iHRIS 4.3 is currently available for testing and should not be used in production yet.


Getting Ready

Here are instructions for installing the supporting software for iHRIS on a Linux (Ubuntu) system. If you need help installing Ubuntu you may want to take a look at these directions for installing a Server or a Desktop system. For a server setup, we recommend using a LTS (long term support) version of Ubuntu.

Note: Unless specifically mentioned, all the commands below are run using a terminal. You can start this in Ubuntu by going to Applications -> Accessories -> Terminal. Any time a command begins with sudo it will prompt for your password because this will be run with administrative privileges. When you run sudo multiple times, only the first time will ask for your password.

Note: Some installation commands will prompt for inputs in the terminal window, usually with a blue background. The mouse doesn't work to click on options here. You can use Tab to move between options and the space bar to check or uncheck selections.

Note: Some commands will launch the gedit file editor. Look at the documentation if you need additional help.

We begin by install a Lamp server (You can find more help here): <source lang="bash"> sudo tasksel install lamp-server </source> If you have never used mysql on your system, you will be asked to set the 'root' password for mysql. We will refer to this password as XXXXX below.

Important: Make sure your email system is correctly configured. Under a default Ubuntu installation, you can do this with one of two commands: <source lang="bash"> sudo apt install postfix sudo dpkg-reconfigure postfix </source>

Follow the on-screen instructions to set up email on your system. For additional help with installing Postfix, look at these instructions. On Debian systems, the same commands can be used, but exim4 is the default MTA instead of postfix

If you are using another Linux distribution, make sure your system can send email properly before continuing.

Configuring MYSQL

Make sure you have in /etc/mysql/mysql.conf.d/mysqld.cnf the following values set: <source lang="bash"> sudo gedit /etc/mysql/mysql.conf.d/mysqld.cnf </source> <source lang="ini"> query_cache_limit = 4M query_cache_size = 64M </source>

Create /etc/mysql/mysql.conf.d/sql-mode.cnf and set the sql-mode variable. <source lang="bash"> sudo gedit /etc/mysql/mysql.conf.d/sql-mode.cnf </source>

<source lang="ini"> [mysqld] sql-mode = "ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION" </source>

If not already configured, set up the MySQL system and root login: <source lang="bash"> sudo mysql_secure_installation </source>

To configure MySQL so iHRIS can create needed functions: <source lang="bash"> mysql -u root -p </source>

Enter the password you set above (XXXXX) for MySQL. If the password isn't working, try running it as the root user as the auth_socket authorization may be enabled: <source lang="bash"> sudo mysql </source>

You will now be able to send commands to MySQL and the prompt should always begin with 'mysql> '. Type these commands: <source lang="mysql"> SET GLOBAL log_bin_trust_function_creators = 1; exit </source>

Now restart mysql so these changes take affect. <source lang="bash"> sudo service mysql restart </source>

[SETTING THE PASSWORD MANUALLY IS OPTIONAL]

If the password you set above doesn't work, you can run the following set of commands to set it manually in the database;

Replace _putyourpasswordhere_ with a MEDIUM strength password by the following criteria. (Only Medium or Strong password will work)

<source> LOW Length >= 8 MEDIUM Length >= 8, numeric, mixed case, and special characters STRONG Length >= 8, numeric, mixed case, special characters and dictionary </source>

<source lang="bash"> $ sudo mysql > ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'putyourpasswordhere'; </source>

To confirm the password is set run this and you should see the column with User=root has a password hash. <source lang="bash"> > SELECT User, Host, HEX(authentication_string) FROM mysql.user; </source> [END SETTING MySQL PASSWORD]

Installing PHP Packages

We need to install a few Pear and PECL packages for PHP. For the Pear packages you can do: <source lang="bash"> sudo apt install php-pear php-gd php-tidy php-intl php-bcmath php-text-password php-mbstring php-uuid </source>


APCu

To install APCu you need to run this command: <source lang='bash'> sudo apt install php-apcu </source>


During certain activities like installation and upgrades you may need more memory than APC uses by default. We also want to turn off the slam defense. We need to edit the configuration file file for apcu: <source lang="bash"> sudo gedit /etc/php/7.2/mods-available/apcu.ini </source> It should look like this: <source lang="ini"> extension=apcu.so apc.enabled=1 apc.write_lock=1 apc.shm_size=100M apc.slam_defense=0 apc.enable_cli=1 </source> See slam defense and this.


Debian Squeeze

If you are using Debian Squeeze, then the value of apc.shm_size should be: <source lang='bash'> apc.shm_size=100 </source>

Install Memcached

With version 4.0.4 and greater of iHRIS you can use memcached to improve performance

Note: Memcached is used to cache data from the database. Thus if you are an a sitaution where you would need to restart the webserver by

sudo systemctl restart apache2

you should now do

sudo systemctl restart apache2 && sudo systemctl restart memcached

To install, simply do <source lang='bash'>

sudo apt install php-memcached memcached

</source>

Set ZendOpcache options

Edit the opcache config file with this command: <source lang="bash"> sudo gedit /etc/php/7.2/mods-available/opcache.ini </source> It should look like this for a production system: <source lang="ini">

configuration for php ZendOpcache module
priority=05

zend_extension=opcache.so opcache.memory_consumption=128M opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 opcache.revalidate_freq=60 opcache.fast_shutdown=1 opcache.enable_cli=1 </source> For a development system you should modify revalidate_freq from 60 to 2: <source lang="ini"> opcache.revalidate_freq=2 </source>

Configuring Apache Web Server

Document Root

In Ubuntu 18.04, the default document root is /var/www/html so when installing any iHRIS applications you will need to use the new directory to place the symlinks. If you are upgrading you may or may not need to update these depending on if you replaced the Apache configuration files during the previous upgrade.

Enable Rewrite Module

You will see later we are using the apache rewrite module. To enable the module: <source lang="bash"> sudo a2enmod rewrite </source>

Enable .htaccess Configuration

Now we need to make sure we can use the .htaccess file. <source lang="bash"> sudo gedit /etc/apache2/apache2.conf </source> Change: <source lang="apache"> <Directory /var/www/>

       Options Indexes FollowSymLinks

AllowOverride None Require all granted </Directory> </source> to: <source lang="apache"> <Directory /var/www/> Options Indexes FollowSymLinks MultiViews AllowOverride All Require all granted </Directory> </source> Save and quit.



Restart Apache

You'll need to restart Apache after making these changes.

sudo service apache2 restart