Add a post abou usb automount in nixos

content/posts/automount_usb_drives_in_nixos/note.md

@@ -0,0 +1,36 @@
+X-Date: 2023-08-15T22:20:00Z
+X-Note-Id: d96dfea4-6e36-4505-858c-3c0c0f7d565b
+Subject: Auto-mount USB drives in NixOS
+X-Slug: automount_usb_drives_in_nixos
+
+One day I've purchased a simple MP3 player, which is recognized by the computer
+as a USB drive when plugged. Since I use a tiling window manager, and not a desktop
+environment, I don't have an easy way to access it from the file manager as you
+would do in, say, Gnome. I don't even use file managers, and mostly operate in the
+terminal.
+
+So, I thought it would be cool if the MP3 player would be automatically mounted to
+a specific place in the filesystem when plugged in. And the permissions would
+be set correctly right away, so my default user would not need any additional action.
+
+I did some research, but there turned out to be surprisingly little information on
+how to do it. So, here you go.
+
+```
+services.udev.extraRules =
+  ''ACTION=="add", SUBSYSTEMS=="usb", SUBSYSTEM=="block", '' +
+  ''ENV{ID_FS_USAGE}=="filesystem", ENV{ID_SERIAL_SHORT}=="<your_device_id>>", '' +
+  ''RUN{program}+="${pkgs.systemd}/bin/systemd-mount --owner <username> '' +
+  ''--no-block --automount=yes --collect $devnode /path/to/mount/to"'';
+```
+
+In this line, you need to replace the `<your_device_id>`, `<username>` and `/path/to/mount/to`.
+
+The `ID_SERIAL_SHORT` can be acquired by doing `udevadm info --query=all --name=/dev/<your_device> | grep ID_SERIAL_SHORT`.
+This ID is based on the filesystem header, so unless you reformat the drive, it should stay the same.
+
+What this thing does is it creates a udev rule that would trigger for your specific device id. It uses systemd-mount, because
+this leads to clean interactions between system services (so you get fewer surprises).
+
+There are many things you can do with this. You can do automated backups of important information for example,
+or sync podcasts (which is what I intend to do).