Installing and running Flex on Ubuntu involves several essential steps. From ensuring that your system meets the necessary prerequisites to downloading and installing the required packages, this guide provides a comprehensive walkthrough to help you configure and run Flex.

Prerequisites for Installing Flex

Before proceeding with the Flex installation on Ubuntu, ensure your system meets the following requirements:

• Supported Ubuntu Version: Verify that your Ubuntu version is compatible with Flex.
• System Requirements: Ensure that your system or virtual machine (VM) meets the necessary requirements.
• SELinux Configuration: If Security-Enhanced Linux (SELinux) is installed, it should be set to permissive mode.
• SSA and JWT: Obtain an SSA (Software Statement Assertion) to trial Flex. The SSA will provide you with a JWT (JSON Web Token) that’s necessary for installation. Make sure to store the SSA in a text file on an accessible path.

Firewall Configuration: Ensure your server firewall is configured to allow HTTPS for proper OpenID and FIDO functionality. You can enable HTTPS with this command:

sudo ufw allow https

Step 1: Downloading and Verifying the Release Package

1. Download the Flex Release Package: Choose the appropriate Flex release for your Ubuntu version and download it from the GitHub FLEX Releases page using the following commands:
3. Import the GPG Key: To verify the authenticity of the downloaded package, import the GPG key. If the key is missing, installation will fail.

Verify the Package Integrity: After downloading, verify the integrity of the package using the sha256sum command. For Ubuntu 20.04, run:

cd /tmp
sha256sum -c flex_5.1.1.ubuntu20.04_amd64.deb.sha256sum

The output should confirm that the package is valid:

flex_5.1.1.ubuntu20.04_amd64.deb: ok

For Ubuntu 20.04:

wget https://github.com/GluuFederation/flex/releases/download/v5.1.1/flex_5.1.1.ubuntu20.04_amd64.deb -P /tmp

For Ubuntu 22.04:

wget https://github.com/GluuFederation/flex/releases/download/v5.1.1/flex_5.1.1.ubuntu22.04_amd64.deb -P /tmp

Step 2: Installing the Flex Release Package

To install Flex, use the apt package manager. Use the appropriate command based on your Ubuntu version:

For Ubuntu 20.04:

apt install -y /tmp/flex_5.1.1.ubuntu20.04_amd64.deb

For Ubuntu 22.04:

apt install -y /tmp/flex_5.1.1.ubuntu22.04_amd64.deb

Step 3: Running the Setup Script

After the installation, run the setup script using the following command:

sudo python3 /opt/jans/jans-setup/flex/flex-linux-setup/flex_setup.py

If you're installing the Admin UI component, you will be prompted to enter the SSA. You can provide the SSA either as text or as a file path. For example:

Install Admin UI [Y/n]: y
Please enter path of file containing SSA or paste SSA (q to exit):

Alternatively, you can pass the SSA file directly to the setup script.

Installing Flex (Fast Lexical Analyzer) on Ubuntu

If you're referring to Flex as the Fast Lexical Analyzer, follow these steps to install it on Ubuntu:

Compile and Install Flex: Compile Flex using the make command:

make
sudo make install

Configure Flex: Make sure m4 is included in your PATH variable:

PATH=$PATH:/usr/local/m4/bin/
export PATH

Then, configure Flex before installation:

./configure --prefix=/usr/local/flex

Extract Files: After downloading, extract the package:

tar -xvzf flex-2.5.33.tar.gz
cd flex-2.5.33

Download Flex: Download the Flex package using the following command:

wget http://prdownloads.sourceforge.net/flex/flex-2.5.33.tar.gz?download

Install m4: Before installing Flex, ensure that m4, a general-purpose macro processor, is installed:

sudo apt install m4

Additional Tips for Ubuntu Users

Development Tools: Make sure you have the required development tools installed to compile Flex from the source code. You can install these tools with:

sudo apt install build-essential

Package Management: You can install Flex directly from the Ubuntu package manager using:

sudo apt-get update
sudo apt-get install flex

Troubleshooting Installation Issues

• Installation Problems: If you encounter issues during installation, consult the available troubleshooting resources for Linux systems.
• Text Mode Installation: If graphical issues arise, try performing a text mode installation instead.
• Fatal Signal 11 Error: This error may occur due to hardware or memory issues. Check your system’s hardware and memory configuration to resolve the problem.

Conclusion

Flex 1.5, an advanced framework originally developed by Macromedia (now Adobe), facilitates the development of Rich Internet Applications (RIAs) that are both scalable and platform-agnostic.

References

1. Run DeepSeek Janus-Pro 7B on Mac: A Comprehensive Guide Using ComfyUI
2. Run DeepSeek Janus-Pro 7B on Mac: Step-by-Step Guide
3. Run DeepSeek Janus-Pro 7B on Windows: A Complete Installation Guide
4. How to Install and Set Up Flex.1 Alpha on macOS
5. How to Install and Set Up Flex.1 Alpha on Windows
6. How to Install and Set Up Flex.1 Alpha on Linux