add /usr/lib/bootc/kargs.d support

Fixes #255. Allows users to create files within /usr/lib/bootc/kargs.d with kernel arguments. These arguments can now be applied on a switch, upgrade, or edit.

General process:
- use ostree commit of fetched container image to return
the file tree
- navigate to /usr/lib/bootc/kargs.d
- read each file within the directory
- calculate the diff between the booted and fetched kargs in kargs.d
- apply the diff to the kargs currently on the running system
- pass the kargs to the stage() function

Signed-off-by: Luke Yang <luyang@redhat.com>

lib/src/cli.rs

@@ -439,6 +439,7 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
         }
     } else {
         let fetched = crate::deploy::pull(sysroot, imgref, opts.quiet).await?;
+        let kargs = crate::kargs::get_kargs(repo, &booted_deployment, fetched.as_ref())?;
         let staged_digest = staged_image.as_ref().map(|s| s.image_digest.as_str());
         let fetched_digest = fetched.manifest_digest.as_str();
         tracing::debug!("staged: {staged_digest:?}");
@@ -460,7 +461,10 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
             println!("No update available.")
         } else {
             let osname = booted_deployment.osname();
-            crate::deploy::stage(sysroot, &osname, &fetched, &spec).await?;
+            let mut opts = ostree::SysrootDeployTreeOpts::default();
+            let kargs: Vec<&str> = kargs.iter().map(|s| s.as_str() ).collect();
+            opts.override_kernel_argv = Some(kargs.as_slice());
+            crate::deploy::stage(sysroot, &osname, &fetched, &spec, Some(opts)).await?;
             changed = true;
             if let Some(prev) = booted_image.as_ref() {
                 if let Some(fetched_manifest) = fetched.get_manifest(repo)? {
@@ -533,6 +537,7 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
     let new_spec = RequiredHostSpec::from_spec(&new_spec)?;
 
     let fetched = crate::deploy::pull(sysroot, &target, opts.quiet).await?;
+    let kargs = crate::kargs::get_kargs(repo, &booted_deployment, fetched.as_ref())?;
 
     if !opts.retain {
         // By default, we prune the previous ostree ref so it will go away after later upgrades
@@ -546,7 +551,10 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
     }
 
     let stateroot = booted_deployment.osname();
-    crate::deploy::stage(sysroot, &stateroot, &fetched, &new_spec).await?;
+    let mut opts = ostree::SysrootDeployTreeOpts::default();
+    let kargs: Vec<&str> = kargs.iter().map(|s| s.as_str() ).collect();
+    opts.override_kernel_argv = Some(kargs.as_slice());
+    crate::deploy::stage(sysroot, &stateroot, &fetched, &new_spec, Some(opts)).await?;
 
     Ok(())
 }
@@ -591,11 +599,16 @@ async fn edit(opts: EditOpts) -> Result<()> {
     }
 
     let fetched = crate::deploy::pull(sysroot, new_spec.image, opts.quiet).await?;
+    let repo = &sysroot.repo();
+    let kargs = crate::kargs::get_kargs(repo, &booted_deployment, fetched.as_ref())?;
 
     // TODO gc old layers here
 
     let stateroot = booted_deployment.osname();
-    crate::deploy::stage(sysroot, &stateroot, &fetched, &new_spec).await?;
+    let mut opts = ostree::SysrootDeployTreeOpts::default();
+    let kargs: Vec<&str> = kargs.iter().map(|s| s.as_str() ).collect();
+    opts.override_kernel_argv = Some(kargs.as_slice());
+    crate::deploy::stage(sysroot, &stateroot, &fetched, &new_spec, Some(opts)).await?;
 
     Ok(())
 }

lib/src/deploy.rs

@@ -221,16 +221,18 @@ async fn deploy(
     stateroot: &str,
     image: &ImageState,
     origin: &glib::KeyFile,
+    opts: Option<ostree::SysrootDeployTreeOpts<'_>>,
 ) -> Result<()> {
     let stateroot = Some(stateroot);
+    let opts = opts.unwrap_or(Default::default());
     // Copy to move into thread
     let cancellable = gio::Cancellable::NONE;
     let _new_deployment = sysroot.stage_tree_with_options(
         stateroot,
         image.ostree_commit.as_str(),
         Some(origin),
         merge_deployment,
-        &Default::default(),
+        &opts,
         cancellable,
     )?;
     Ok(())
@@ -255,6 +257,7 @@ pub(crate) async fn stage(
     stateroot: &str,
     image: &ImageState,
     spec: &RequiredHostSpec<'_>,
+    opts: Option<ostree::SysrootDeployTreeOpts<'_>>,
 ) -> Result<()> {
     let merge_deployment = sysroot.merge_deployment(Some(stateroot));
     let origin = origin_from_imageref(spec.image)?;
@@ -264,6 +267,7 @@ pub(crate) async fn stage(
         stateroot,
         image,
         &origin,
+        opts,
     )
     .await?;
     crate::deploy::cleanup(sysroot).await?;

lib/src/install/config.rs

@@ -47,6 +47,7 @@ pub(crate) struct InstallConfiguration {
     /// Kernel arguments, applied at installation time
     #[serde(skip_serializing_if = "Option::is_none")]
     pub(crate) kargs: Option<Vec<String>>,
+    pub(crate) arch: Option<Vec<String>>,
 }
 
 fn merge_basic<T>(s: &mut Option<T>, o: Option<T>) {
@@ -100,9 +101,19 @@ impl Mergeable for InstallConfiguration {
         merge_basic(&mut self.block, other.block);
         self.filesystem.merge(other.filesystem);
         if let Some(other_kargs) = other.kargs {
-            self.kargs
-                .get_or_insert_with(Default::default)
-                .extend(other_kargs)
+            // if arch is specified, only apply kargs if it matches the current arch
+            // if arch is not specified, apply kargs unconditionally
+            if let Some(other_arch) = other.arch {
+                if other_arch.contains(&std::env::consts::ARCH.to_string()) {
+                    self.kargs
+                        .get_or_insert_with(Default::default)
+                        .extend(other_kargs.clone());
+                }
+            } else {
+                self.kargs
+                    .get_or_insert_with(Default::default)
+                    .extend(other_kargs)
+            }
         }
     }
 }
@@ -161,7 +172,7 @@ pub(crate) fn load_config() -> Result<Option<InstallConfiguration>> {
         let buf = std::fs::read_to_string(&path)?;
         let mut unused = std::collections::HashSet::new();
         let de = toml::Deserializer::new(&buf);
-        let c: InstallConfigurationToplevel = serde_ignored::deserialize(de, |path| {
+        let mut c: InstallConfigurationToplevel = serde_ignored::deserialize(de, |path| {
             unused.insert(path.to_string());
         })
         .with_context(|| format!("Parsing {path:?}"))?;
@@ -174,6 +185,15 @@ pub(crate) fn load_config() -> Result<Option<InstallConfiguration>> {
                 config.merge(install);
             }
         } else {
+            // If arch is specified and doesn't match the current arch, remove kargs
+            // We need to add this since the merge function isn't applied for the first config file
+            if let Some(ref mut install) = c.install {
+                if let Some(arch) = install.arch.as_ref() {
+                    if !arch.contains(&std::env::consts::ARCH.to_string()) {
+                        install.kargs = None;
+                    }
+                }
+            }
             config = c.install;
         }
     }
@@ -319,3 +339,205 @@ block = ["tpm2-luks"]"##,
     // And verify passing a disallowed config is an error
     assert!(install.get_block_setup(Some(BlockSetup::Direct)).is_err());
 }
+
+#[test]
+/// Verify that kargs are only applied to supported architectures
+fn test_arch() {
+    // no arch specified, kargs ensure that kargs are applied unconditionally
+    std::env::set_var("ARCH", "x86_64");
+    let c: InstallConfigurationToplevel = toml::from_str(
+        r##"[install]
+root-fs-type = "xfs"
+"##,
+    )
+    .unwrap();
+    let mut install = c.install.unwrap();
+    let other = InstallConfigurationToplevel {
+        install: Some(InstallConfiguration {
+            kargs: Some(
+                ["console=tty0", "nosmt"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            ..Default::default()
+        }),
+    };
+    install.merge(other.install.unwrap());
+    assert_eq!(
+        install.kargs,
+        Some(
+            ["console=tty0", "nosmt"]
+                .into_iter()
+                .map(ToOwned::to_owned)
+                .collect()
+        )
+    );
+    std::env::set_var("ARCH", "aarch64");
+    let c: InstallConfigurationToplevel = toml::from_str(
+        r##"[install]
+root-fs-type = "xfs"
+"##,
+    )
+    .unwrap();
+    let mut install = c.install.unwrap();
+    let other = InstallConfigurationToplevel {
+        install: Some(InstallConfiguration {
+            kargs: Some(
+                ["console=tty0", "nosmt"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            ..Default::default()
+        }),
+    };
+    install.merge(other.install.unwrap());
+    assert_eq!(
+        install.kargs,
+        Some(
+            ["console=tty0", "nosmt"]
+                .into_iter()
+                .map(ToOwned::to_owned)
+                .collect()
+        )
+    );
+
+    // one arch matches and one doesn't, ensure that kargs are only applied for the matching arch
+    std::env::set_var("ARCH", "x86_64");
+    let c: InstallConfigurationToplevel = toml::from_str(
+        r##"[install]
+root-fs-type = "xfs"
+"##,
+    )
+    .unwrap();
+    let mut install = c.install.unwrap();
+    let other = InstallConfigurationToplevel {
+        install: Some(InstallConfiguration {
+            kargs: Some(
+                ["console=ttyS0", "foo=bar"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            arch: Some(
+                ["x86_64"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            ..Default::default()
+        }),
+    };
+    install.merge(other.install.unwrap());
+    assert_eq!(
+        install.kargs,
+        Some(
+            ["console=ttyS0", "foo=bar"]
+                .into_iter()
+                .map(ToOwned::to_owned)
+                .collect()
+        )
+    );
+    let other = InstallConfigurationToplevel {
+        install: Some(InstallConfiguration {
+            kargs: Some(
+                ["console=tty0", "nosmt"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            arch: Some(
+                ["aarch64"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            ..Default::default()
+        }),
+    };
+    install.merge(other.install.unwrap());
+    assert_eq!(
+        install.kargs,
+        Some(
+            ["console=ttyS0", "foo=bar"]
+                .into_iter()
+                .map(ToOwned::to_owned)
+                .collect()
+        )
+    );
+
+    // multiple arch specified, ensure that kargs are applied to both archs
+    std::env::set_var("ARCH", "x86_64");
+    let c: InstallConfigurationToplevel = toml::from_str(
+        r##"[install]
+root-fs-type = "xfs"
+"##,
+    )
+    .unwrap();
+    let mut install = c.install.unwrap();
+    let other = InstallConfigurationToplevel {
+        install: Some(InstallConfiguration {
+            kargs: Some(
+                ["console=tty0", "nosmt"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            arch: Some(
+                ["x86_64", "aarch64"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            ..Default::default()
+        }),
+    };
+    std::env::set_var("ARCH", "x86_64");
+    install.merge(other.install.unwrap());
+    assert_eq!(
+        install.kargs,
+        Some(
+            ["console=tty0", "nosmt"]
+                .into_iter()
+                .map(ToOwned::to_owned)
+                .collect()
+        )
+    );
+    std::env::set_var("ARCH", "aarch64");
+    let c: InstallConfigurationToplevel = toml::from_str(
+        r##"[install]
+root-fs-type = "xfs"
+"##,
+    )
+    .unwrap();
+    let mut install = c.install.unwrap();
+    let other = InstallConfigurationToplevel {
+        install: Some(InstallConfiguration {
+            kargs: Some(
+                ["console=tty0", "nosmt"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            arch: Some(
+                ["x86_64", "aarch64"]
+                    .into_iter()
+                    .map(ToOwned::to_owned)
+                    .collect(),
+            ),
+            ..Default::default()
+        }),
+    };
+    std::env::set_var("ARCH", "x86_64");
+    install.merge(other.install.unwrap());
+    assert_eq!(
+        install.kargs,
+        Some(
+            ["console=tty0", "nosmt"]
+                .into_iter()
+                .map(ToOwned::to_owned)
+                .collect()
+        )
+    );
+}