Using blkid utility to determine dev name by gpt partlabel.

src/main.rs

@@ -39,7 +39,7 @@ use nyan_system::ExecCommandError;
 const BEE_CAT: &str = include_str!("bee_cat.txt");
 
 //const ROOT_PARTLABEL: &str = "bee-root";
-const ROOT_DEV: &str = "/dev/disk/by-partlabel/bee-root";
+const ROOT_PARTLABEL: &str = "bee-root";
 const TMP_ROOT: &str = "/mnt/bee_root";
 const TMP_ROOT_SNAPS: &str = "/mnt/bee-root/bzz_snaps";
 const SYS_INIT: &str = "/sbin/init";
@@ -74,9 +74,9 @@ enum NyanitState {
 }
 
 /// Mounting bee-root and chiking if there any snapshots
-fn mount_and_check_snaps() -> Result<NyanitState, ExecCommandError> {
+fn mount_and_check_snaps(bee_root_dev: &str) -> Result<NyanitState, ExecCommandError> {
     // mount bee-root
-    nyan_system::mount_bee_root(TMP_ROOT, ROOT_DEV)?;
+    nyan_system::mount_bee_root(TMP_ROOT, bee_root_dev)?;
 
     // list snaps if any
     let mut snaps_list = nyan_system::list_bzzpss_snaps(TMP_ROOT_SNAPS)?;
@@ -90,23 +90,27 @@ fn mount_and_check_snaps() -> Result<NyanitState, ExecCommandError> {
     Ok(NyanitState::HandOff(TMP_ROOT.into()))
 }
 
-fn init_stage() -> Result<NyanitState, ExecCommandError> {
+fn init_stage() -> Result<(String, NyanitState), ExecCommandError> {
     // mount sysfss
     nyan_system::prepare_env().map_err(|ex| format!("prepare_env error: {}", ex))?;
 
+    // get bee-root device name aka /dev/sda1
+    let bee_root_dev = nyan_system::find_partlabel(ROOT_PARTLABEL)?;
     // check if device is encrypted
-    if nyan_system::bzzpss_dev_encrypted(ROOT_DEV).map_err(|ex| format!("Error checking if device is encrypted: {}", ex))? {
+    if nyan_system::bzzpss_dev_encrypted(&bee_root_dev).map_err(|ex| format!("Error checking if device is encrypted: {}", ex))? {
         // if encrypted return EnterPassword so used get promted for pass
-        return Ok(NyanitState::EnterPassword);
+        return Ok((bee_root_dev, NyanitState::EnterPassword));
     }
 
     // if unencrypted
-    mount_and_check_snaps()
+    let check_res = mount_and_check_snaps(&bee_root_dev)?;
+    Ok((bee_root_dev, check_res))
 }
 
 struct NyanitTUI<'a> {
     exit: bool,
     state: NyanitState,
+    bee_root_dev: String,
     list_state: ListState,
     time_counter: u32,
     textarea: Option<TextArea<'a>>,
@@ -117,6 +121,7 @@ impl NyanitTUI<'_> {
         Ok(Self {
             exit: false,
             state: NyanitState::Init,
+            bee_root_dev: String::new(),
             list_state: ListState::default().with_selected(Some(0)),
             time_counter: 0,
             textarea: None,
@@ -126,7 +131,10 @@ impl NyanitTUI<'_> {
     /// runs the application's main loop until the user quits
     pub fn run(&mut self) -> io::Result<()> {
         self.state = match init_stage() {
-            Ok(st) => st,
+            Ok(res) => {
+                self.bee_root_dev = res.0;
+                res.1
+            },
             Err(ex) => {
                 NyanitState::Error(format!("Error while trying to bzzz-pss things:\n{}", ex))
             },
@@ -276,11 +284,11 @@ impl NyanitTUI<'_> {
                         // try to unlock if enter pressed
                         Event::Key(event::Key::Char('\n')) => {
                             let password = self.textarea.as_ref().unwrap().lines()[0].clone();
-                            match nyan_system::bcachefs_unlock(password, ROOT_DEV) {
+                            match nyan_system::bcachefs_unlock(password, &self.bee_root_dev) {
                                 Ok(unlocked) => {
                                     if unlocked {
                                         // need to check for subvolumes and stuff
-                                        self.state = match mount_and_check_snaps() {
+                                        self.state = match mount_and_check_snaps(&self.bee_root_dev) {
                                             Ok(st) => {
                                                 self.time_counter = 0;
                                                 st

src/nyan_system.rs

@@ -110,6 +110,34 @@ pub fn exec_command(cmd: &str, args: &Vec<&str>) -> Result<(), ExecCommandError>
     }
 }
 
+/// Gets device node aka /dev/sda1 from gpr partition label
+/// blkid -s PARTLABEL --match-token "PARTLABEL=primary"
+pub fn find_partlabel(partlabel: &str) -> Result<String, ExecCommandError> {
+    let out = Command::new("/usr/bin/blkid")
+        .args([
+            "-s",
+            "PARTLABEL",
+            "--match-token",
+            format!("\"PARTLABEL={}\"", partlabel).as_str(),
+        ])
+        .output()?;
+    if out.status.success() {
+        let out_text = String::from_utf8(out.stdout)?;
+
+        let split_res = out_text.split_once(':').ok_or_else(|| {
+            ExecCommandError::Other(format!("Unexpected blkid output format: \"{}\"", out_text))
+        })?;
+
+        Ok(split_res.0.to_string())
+    } else {
+        Err(ExecCommandError::Other(format!(
+            "Connot find device with partlabel={} or something other is wrong: \"{}\"",
+            partlabel,
+            String::from_utf8(out.stderr).unwrap_or_else(|_| String::new())
+        )))
+    }
+}
+
 /// exec given command with arguments, returning stdout parsed to UTF-8 string
 /// capturing stderr in case or failure
 // pub fn exec_command_out(cmd: &str, args: &Vec<&str>) -> Result<String, ExecCommandError> {
@@ -224,7 +252,7 @@ pub fn list_bzzpss_snaps(snaps_dir: &str) -> Result<Vec<String>, ExecCommandErro
 // mount -t sysfs none /sys
 // modprobe bcachefs
 pub fn prepare_env() -> Result<(), String> {
-    use nix::mount::{mount, MsFlags};
+    use nix::mount::{MsFlags, mount};
 
     use std::path::Path;