Installing on RedHat and CentOS

Danger

• If you decide to install Red Hat, be aware that you should have a licensed Red Hat version; otherwise, you won’t be able to install updates.
• Red Hat ISO can be downloaded from https://developers.redhat.com/products/rhel/download for testing, but you must register first.
• Remember that CentOS is deprecated, so you should switch to CentOS Stream.

Tip

This installation guide works for other Red Hat-based distributions like Oracle Linux and Rocky Linux.

This guide has been validated with the following:

• Red Hat 8.7
• Red Hat 9.1
• Rocky Linux 9.1
• CentOS Stream 9

Caution

To install OpenKM, the server needs access to download.openkm.com and update.openkm.com; please verify before installing.

In case of using a proxy to access the Internet, please look at Using the installer.

Preliminaries

Ensure you have enough disk space to install OpenKM and store the document repository:

$ df -h

Once verified, create the “openkm” user:

$ adduser openkm

If Java 8 is still not installed, please install the following:

$ yum install java-1.8.0-openjdk

Caution

If Java 8 packages are not available in your distro repositories, you need to download and install them from Eclipse Temurin.

Caution

OpenKM currently works only with Java 8, so once the installation process is completed, verify that the default version is Java 8:

# java -version
openjdk version "1.8.0_352"
OpenJDK Runtime Environment (build 1.8.0_352-b08)
OpenJDK 64-Bit Server VM (build 25.352-b08, mixed mode)

Otherwise, set Java 8 as the default:

$ update-alternatives --config java

If you have any other preference for a database, we suggest installing MariaDB:

$ yum install mariadb-server

After that, enable and start the MariaDB service:

$ systemctl enable mariadb
$ systemctl start mariadb

Installing OpenKM

You can choose between installing OpenKM at “/home/openkm” or “/opt.” In any case, go to the selected path and download the installer.

It’s a text-based installer, so you must execute it from the console as root. This is because it needs to install package dependencies and configure OpenKM as a service:

$ java -jar OKMInstaller.jar

Remember to check Using the installer in case of using a proxy to access the Internet.

When the installation process has finished, please ensure that Java 8 is the default:

$ java -version

Otherwise, set it as the default:

$ update-alternatives --config java

Once verified, start the required services:

$ systemctl start xvfb openkm

You can verify the status of these services by running:

$ systemctl status xvfb openkm

More info at:

• How do I turn SELinux off in Red Hat Enterprise Linux?
• Install Extra Packages for Enterprise Linux (EPEL)
• Remove the yum repo using yum

Enable remote access

Red Hat does not allow connections to port 8080 by default, so you need to open this port in the firewall:

$ firewall-cmd --zone=public --permanent --add-port=8080/tcp
$ firewall-cmd --reload

Post-installation checklist

To verify the installation was successful, please use this checklist:

• Verify that the default Java is Java 8.
• Verify you can access OpenKM from another computer.
• Try to log in with the default okmAdmin / admin user and password.
• Upload a Word document and check if the thumbnail is generated and the preview is shown.

Troubleshooting

If you have a problem with the thumbnail generation, please verify that you have the ImageMagick package installed and that the “convert” application works. 

Download a sample image from Sample PNG Image and try to generate a thumbnail:

$ wget https://www.sample-videos.com/img/Sample-png-image-1mb.png
$ convert -thumbnail '80x80>' -background 'white' -flatten Sample-png-image-1mb.png sample-output.png