I was trying to play around using my local mac emacs slime to connect the swank server on my raspberry pi. Initially, it cannot work, but I use the ssh tunnel to forward the ports to make it work. However, I try to figure out why it cannot connect directly. It is because the raspberry pi doesn’t open the port.

So I installed the ufw and added the port 4005 (swank default port) to rule, then sudo ufw enable, then restarted the raspberry pi, then I lost my permission of ssh because the port 22 doesn’t open. It is an extremely stupid mistake.

Try to solve the problem first

The easiest way is to connect a keyboard, a mouse, and a monitor. Unfortunately, I don’t have a micro HDMI for the monitor, either a mouse or a keyboard.

mount the SD card to macOS

So I was thinking if I could mount the SD card to my mac and change the ufw rules located in /etc/ufw/user.rules. However, I need to install the macfuse and ext4fuse to mount the ext4 file system which my raspberry pi is using.

Furthermore, ext4fuse cannot install through homebrew. So I find this repo and built it in my local. And need to restart to change the kernel extension preference in safe mode for using the macfuse.

After all these operations, sudo ./ext4fuse /dev/disk6s2 ~/Desktop/rasberry-pi -o allow_other,rw to mount the SD card file system to ~/Desktop/rasberry-pi.

But, the ,rw is unnecessary because the file system is read-only. It is sad that I saw the config file but cannot change it.

Re-make raspberry pi system

Looks like I have to re-make my raspberry pi system. Luckily, raspberry pi has a very easy management app to re-make the whole system. This is the official document: https://www.raspberrypi.com/documentation/computers/getting-started.html#installing-the-operating-system

The thing is, in advanced options, I can init setting the ssh, hostname, username, password, and wifi. I don’t remember they being there in 2019 (the time I bought this raspberry pi), but it is very convenient it has.

ufw first

This time I do the ufw first in case something is wrong again, then I can re-make the system again without losing a lot of work.

My raspberry pi is hosted inside the intern network in my home, so I can run sudo ufw allow from 192.168.0.0/16 to achieve it.

some packages

Then I need to install some packages I would like to use. Emacs, zsh, etc.

VNC

The major usage of my raspberry pi is becoming my disk mounting point and plex server. Back in 2019, I found an amazing tutorial that made the connection between raspberry pi and mac. Here is the link: https://github.com/HackerShackOfficial/Raspberry-Pi-VNC-Mac

The only thing that needs to worry about is the netatalk might changes its configuration in 2019. I keep getting the

There are no shares available or you are not allowed to access them on the server.

when I try to connect it.

After some search, I just need to change (un-comment) the configuration of netatalk

[Homes]
basedir regex = /home

Then the connection is good.