Preparing Container Runtime Environment

Setting up the correct container runtime environment is essential for running containerized applications efficiently. This guide provides detailed instructions for preparing a container runtime environment on RHEL 8 and RHEL 9, including prerequisites, installation steps, considerations, and troubleshooting tips.

Container Runtime Requirements

New installations:
- Podman is the default container runtime for RHEL 8 and RHEL 9. However, before proceeding with the BigFix MCM and BigFix Mobile installation, verify that Podman is installed and running.
- On RHEL 8, using Podman Compose requires additional setup, as the default Python version does not include support for certain necessary libraries.
  Note: Recommendation: If you're starting fresh or looking for minimal setup, choose RHEL 9 for seamless Podman Compose support.
Upgrade: Before upgrading, remove Docker and install Podman. For instructions, refer to Migrating from Docker to Podman

Setting up Podman

Check Podman Version
Podman is included by default in RHEL 8 and RHEL 9. Check Podman version using the following command.
```
podman --version
```
It displays the installed version of Podman and ensures Podman is installed and available on the system. If it is not available, install it manually.
```
sudo dnf install -y podman
```
Check Python Version and install the required version If Necessary
```
python3 --version
```
- Displays the installed version of Python 3.
- If Python 3.9+ is installed, proceed to step #3.
- If installed Python version is older than 3.9, complete the following steps:
  1. Install Python 3.9
```
dnf install python39
```
    This installs Python 3.9 alongside the existing system version.
  2. Check Current Python 3 Version
```
python3 --version
```
    Output will likely show: Python 3.6.x (or whatever version was previously set as default).
  3. Configure the Default Python Version
```
alternatives --config python3
```
    To change the default version to 3.9, when prompted, select Python 3.9 by using "+" and "Enter".
  4. Verify the Change
```
python3 --version
```
    Now, the python version will be changed to v3.9
Install pip (Python Package Manager)
```
sudo dnf install -y python3-pip
```
- Installs pip3, the package manager for Python, using dnf (the package manager for RHEL-based systems).
- The -y flag automatically confirms the installation.
Verify pip Installation
```
pip3 --version
```
Displays the installed version of pip3, ensuring it's installed and functional.
Install Podman Compose using pip
```
pip3 install podman-compose
```
Installs Podman Compose, allowing users to manage multiple Podman containers using a docker-compose.yml file.
Verify Podman Compose Installation
```
ls /usr/local/bin/podman-compose
```
Checks if podman-compose is present in /usr/local/bin/, which is a common location for executables installed via pip.
Create a Symlink for Podman
```
ln -s /usr/bin/podman /usr/local/bin/podman
```
Ensures podman is accessible in /usr/local/bin/ by linking it to /usr/bin/podman.
Create a Symlink for Podman Compose
```
ln -s /usr/local/bin/podman-compose /usr/bin/podman-compose
```
Creates a symbolic link (ln -s) so that podman-compose can be executed from /usr/bin/, making it accessible system-wide.
Verify Podman Compose Again
```
podman-compose --version
```
Confirms that podman-compose is correctly installed and available after the symlink.
Verify if Podman is installed and executable
```
podman ps
podman images
```
Install MDM server
Verify if Podman containers are running as expected
```
podman ps
```
Similar to docker ps, it displays all currently running Podman containers.
Verify if Podman images are downloaded
```
podman images
```
Shows all locally available container images, including their repository names, tags, and sizes.

Troubleshooting

Podman Issues

Podman command not recognized:
```
podman --version
```
If missing, ensure Podman is installed:
```
sudo dnf install -y podman
```
Podman unable to pull images:
```
podman pull registry.fedoraproject.org/fedora:latest
```
Check network connectivity and repository access.

Frequently Asked Questions (FAQ)

Q1: Can I run Docker and Podman together?: A: No. It may lead to conflicts due to differences in how they manage containers, images, and storage.

Q2: How can I migrate from Docker to Podman?: A: Uninstall Docker, install and set up Podman, and upgrade MCM to the latest version through WebUI.

Next Steps

Once all prerequisites are met along with setting up Podman, follow the installation instructions Installing MDM services to complete the setup.