component: Make update metadata generation to be optional

Currently, the `bootupctl backend generate-update-metadata` command tries
to generate an update layout for each component, and it bails out if one
of the components can't be installed.

There are systems in which some of the bootupd components are not needed
(e.g.: x86_64 EFI-only systems). But if one of the requirements for one
of the components is not meet (e.g.: grub2-install is missing for BIOS),
this will lead to a fatal error instead of just skipping the component
that is not supported.

To prevent this, let's make the update layout generation to be optional.

Signed-off-by: Javier Martinez Canillas <[email protected]>

Author: martinezjavier

src/bios.rs

@@ -127,7 +127,7 @@ impl Component for Bios {
         })
     }
 
-    fn generate_update_metadata(&self, sysroot_path: &str) -> Result<ContentMetadata> {
+    fn generate_update_metadata(&self, sysroot_path: &str) -> Result<Option<ContentMetadata>> {
         let grub_install = Path::new(sysroot_path).join(GRUB_BIN);
         if !grub_install.exists() {
             bail!("Failed to find {:?}", grub_install);
@@ -136,7 +136,7 @@ impl Component for Bios {
         // Query the rpm database and list the package and build times for /usr/sbin/grub2-install
         let meta = packagesystem::query_files(sysroot_path, [&grub_install])?;
         write_update_metadata(sysroot_path, self, &meta)?;
-        Ok(meta)
+        Ok(Some(meta))
     }
 
     fn query_adopt(&self, devices: &Option<Vec<String>>) -> Result<Option<Adoptable>> {

src/bootupd.rs

@@ -199,12 +199,18 @@ pub(crate) fn generate_update_metadata(sysroot_path: &str) -> Result<()> {
     std::fs::create_dir_all(&updates_dir)
         .with_context(|| format!("Failed to create updates dir {:?}", &updates_dir))?;
     for component in get_components().values() {
-        let v = component.generate_update_metadata(sysroot_path)?;
-        println!(
-            "Generated update layout for {}: {}",
-            component.name(),
-            v.version,
-        );
+        if let Some(v) = component.generate_update_metadata(sysroot_path)? {
+            println!(
+                "Generated update layout for {}: {}",
+                component.name(),
+                v.version,
+            );
+        } else {
+            println!(
+                "Generating update layout for {} was not possible, skipping.",
+                component.name(),
+            );
+        }
     }
 
     Ok(())

src/component.rs

@@ -62,7 +62,7 @@ pub(crate) trait Component {
     /// this is an `rpm-ostree compose tree` for example.  For a dual-partition
     /// style updater, this would be run as part of a postprocessing step
     /// while the filesystem for the partition is mounted.
-    fn generate_update_metadata(&self, sysroot: &str) -> Result<ContentMetadata>;
+    fn generate_update_metadata(&self, sysroot: &str) -> Result<Option<ContentMetadata>>;
 
     /// Used on the client to query for an update cached in the current booted OS.
     fn query_update(&self, sysroot: &openat::Dir) -> Result<Option<ContentMetadata>>;

src/efi.rs

@@ -460,7 +460,7 @@ impl Component for Efi {
         })
     }
 
-    fn generate_update_metadata(&self, sysroot: &str) -> Result<ContentMetadata> {
+    fn generate_update_metadata(&self, sysroot: &str) -> Result<Option<ContentMetadata>> {
         let sysroot_path = Utf8Path::new(sysroot);
 
         // copy EFI files to updates dir from usr/lib/efi
@@ -533,7 +533,7 @@ impl Component for Efi {
         };
 
         write_update_metadata(sysroot, self, &meta)?;
-        Ok(meta)
+        Ok(Some(meta))
     }
 
     fn query_update(&self, sysroot: &openat::Dir) -> Result<Option<ContentMetadata>> {