Add support for multiple port forwarding parameters in QEMU startup script

[John15321]

Add support for multiple port forwarding parameters in QEMU startup script

This PR introduces a new feature to the flatcar_qemu_startup.sh script, allowing users to specify multiple port forwards using the -f option. This enhancement improves the flexibility and usability of the script by enabling users to forward multiple ports from the host to the guest VM.

Key Changes:

Added the -f option to specify port forwards in the format host_port:guest_port. Updated the script to process multiple -f options and construct the appropriate QEMU command line arguments. Modified the usage instructions to include the new -f option.

How to Use:

To use the new port forwarding feature, specify the -f option followed by the host_port:guest_port pairs. Multiple -f options can be used to forward multiple ports. For example:

./flatcar_production_qemu.sh -M 6144 -f 25565:25565 -f 25575:25575 -f 2223:2223 -i ./config.json -- -display curses

This command sets the VM memory to 6144 MB, forwards ports 25565, 25575, and 2223, and uses a specified Ignition config file.

Testing Done:

Verified that the script correctly processes multiple -f options and constructs the QEMU command line with the specified port forwards. Tested the script with various combinations of port forwards to ensure proper functionality. Example command used for testing:

./flatcar_production_qemu.sh -M 6144 -f 25565:25565 -f 25575:25575 -f 2223:2223 -i ./config.json -- -display curses

Confirmed that the VM starts with the specified port forwards and that the ports are accessible from the host.

• Changelog entries added in the respective changelog/ directory (user-facing change, bug fix, security fix, update)
• Inspected CI output for image differences: /boot and /usr size, packages, list files for any missing binaries, kernel modules, config files, kernel modules, etc.

[John15321]

One thing that Im not sure about is where I should add the mention about it to the changelog file? 🤔

[tormath1]

One thing that Im not sure about is where I should add the mention about it to the changelog file? 🤔

Yes please. In the changelog/changes folder, using the past tense, e.g:

Added support ... (flatcar/scripts#2575)

[github-actions]

Build action triggered: https://github.com/flatcar/scripts/actions/runs/12742931278

[chewi]

Not using shell built-ins makes me cry. 😛

Suggested change

	for port in $PORT_FORWARDS; do
	host_port=$(echo "$port" | cut -d':' -f1)
	guest_port=$(echo "$port" | cut -d':' -f2)
	for port in ${PORT_FORWARDS}; do
	host_port=${port%:*}
	guest_port=${port#*:}

[John15321]

Done

[tormath1]

Thanks, feel free to squash your commits before merging. :)

[John15321]

Commits squashed