grubconfig: minor changes to replace variables using const

Author: HuijingHei

src/grubconfigs.rs

@@ -12,7 +12,7 @@ use crate::freezethaw::fsfreeze_thaw_cycle;
 
 /// The subdirectory of /boot we use
 const GRUB2DIR: &str = "grub2";
-const CONFIGDIR: &str = "/usr/lib/bootupd/grub2-static";
+const CONFIGDIR: &str = "usr/lib/bootupd/grub2-static";
 const DROPINDIR: &str = "configs.d";
 // The related grub files
 const GRUBENV: &str = "grubenv";
@@ -43,11 +43,10 @@ pub(crate) fn install(
     }
 
     let configdir = if let Some(src_root) = src_root {
-        // strip the leading `/` to make the path relative to the given
-        // source root
-        src_root.sub_dir(Path::new(CONFIGDIR).strip_prefix("/")?)?
+        src_root.sub_dir(CONFIGDIR)?
     } else {
-        openat::Dir::open(Path::new(CONFIGDIR))?
+        // Open / if there is no source root
+        openat::Dir::open("/")?.sub_dir(CONFIGDIR)?
     };
 
     let mut config = String::from("# Generated by bootupd / do not edit\n\n");
@@ -58,7 +57,7 @@ pub(crate) fn install(
         .read_to_string(&mut pre)?;
     config.push_str(pre.as_str());
 
-    let dropindir = configdir.sub_dir(Path::new(DROPINDIR))?;
+    let dropindir = configdir.sub_dir(DROPINDIR)?;
     // Sort the files for reproducibility
     let mut entries = dropindir
         .list_dir(".")?
@@ -85,7 +84,7 @@ pub(crate) fn install(
 
     let grub2dir = bootdir.sub_dir(GRUB2DIR)?;
     grub2dir
-        .write_file_contents("grub.cfg", GRUBCONFIG_FILE_MODE, config.as_bytes())
+        .write_file_contents(GRUBCONFIG, GRUBCONFIG_FILE_MODE, config.as_bytes())
         .context("Copying grub-static.cfg")?;
     println!("Installed: grub.cfg");
 
@@ -113,7 +112,7 @@ pub(crate) fn install(
     if let Some(vendordir) = installed_efi_vendor {
         log::debug!("vendordir={:?}", &vendordir);
         let vendor = PathBuf::from(vendordir);
-        let target = &vendor.join("grub.cfg");
+        let target = &vendor.join(GRUBCONFIG);
         let dest_efidir = target_root
             .sub_dir_optional("boot/efi/EFI")
             .context("Opening /boot/efi/EFI")?;