Merge pull request #1157 from cgwalters/install-finalize

install: Add a generic `install finalize`

Author: cgwalters

Makefile

@@ -59,15 +59,22 @@ test-bin-archive: all
 test-tmt:
 	cargo xtask test-tmt
 
-# Checks extra rust things (formatting, a few extra rust warnings, and select clippy lints)
+# This gates CI by default. Note that for clippy, we gate on
+# only the clippy correctness and suspicious lints, plus a select
+# set of default rustc warnings.
+# We intentionally don't gate on this for local builds in cargo.toml
+# because it impedes iteration speed.
+CLIPPY_CONFIG = -A clippy::all -D clippy::correctness -D clippy::suspicious -Dunused_imports -Ddead_code
 validate-rust:
 	cargo fmt -- --check -l
-	cargo check
-	(cd lib && cargo check --no-default-features)
 	cargo test --no-run
-	cargo clippy -- -D clippy::correctness -D clippy::suspicious
+	(cd lib && cargo check --no-default-features)
+	cargo clippy -- $(CLIPPY_CONFIG)
 	env RUSTDOCFLAGS='-D warnings' cargo doc --lib
 .PHONY: validate-rust
+fix-rust:
+	cargo clippy --fix --allow-dirty -- $(CLIPPY_CONFIG)
+.PHONY: fix-rust
 
 validate: validate-rust
 	ruff check

docs/src/bootc-install.md

@@ -161,6 +161,26 @@ storage or filesystem setups, but reuses the "top half" of the logic.
 For example, a goal is to change [Anaconda](https://github.com/rhinstaller/anaconda/)
 to use this.
 
+#### Postprocessing after to-filesystem
+
+Some installation tools may want to inject additional data, such as adding
+an `/etc/hostname` into the target root. At the current time, bootc does
+not offer a direct API to do this. However, the backend for bootc is
+ostree, and it is possible to enumerate the deployments via ostree APIs.
+
+We hope to provide a bootc-supported method to find the deployment in
+the future.
+
+However, for tools that do perform any changes, there is a new
+`bootc install finalize` command which is optional, but recommended
+to run as the penultimate step before unmounting the target filesystem.
+
+This command will perform some basic sanity checks and may also
+perform fixups on the target root. For example, a direction
+currently for bootc is to stop using `/etc/fstab`. While `install finalize`
+does not do this today, in the future it may automatically migrate
+`etc/fstab` to `rootflags` kernel arguments.
+
 ### Using `bootc install to-disk --via-loopback`
 
 Because every `bootc` system comes with an opinionated default installation

lib/src/cli.rs

@@ -209,6 +209,12 @@ pub(crate) enum InstallOpts {
     /// will be wiped, but the content of the existing root will otherwise be retained, and will
     /// need to be cleaned up if desired when rebooted into the new root.
     ToExistingRoot(crate::install::InstallToExistingRootOpts),
+    /// Execute this as the penultimate step of an installation using `install to-filesystem`.
+    ///
+    Finalize {
+        /// Path to the mounted root filesystem.
+        root_path: Utf8PathBuf,
+    },
     /// Intended for use in environments that are performing an ostree-based installation, not bootc.
     ///
     /// In this scenario the installation may be missing bootc specific features such as
@@ -1121,6 +1127,9 @@ async fn run_from_opt(opt: Opt) -> Result<()> {
                 let rootfs = &Dir::open_ambient_dir("/", cap_std::ambient_authority())?;
                 crate::install::completion::run_from_anaconda(rootfs).await
             }
+            InstallOpts::Finalize { root_path } => {
+                crate::install::install_finalize(&root_path).await
+            }
         },
         Opt::ExecInHostMountNamespace { args } => {
             crate::install::exec_in_host_mountns(args.as_slice())

lib/src/install.rs

@@ -1452,6 +1452,9 @@ async fn install_to_filesystem_impl(state: &State, rootfs: &mut RootSetup) -> Re
         // descriptors.
     }
 
+    // Run this on every install as the penultimate step
+    install_finalize(&rootfs.physical_root_path).await?;
+
     // Finalize mounted filesystems
     if !rootfs.skip_finalize {
         let bootfs = rootfs.boot.as_ref().map(|_| ("boot", "boot"));
@@ -1909,6 +1912,24 @@ pub(crate) async fn install_to_existing_root(opts: InstallToExistingRootOpts) ->
 
     install_to_filesystem(opts, true).await
 }
+
+/// Implementation of `bootc install finalize`.
+pub(crate) async fn install_finalize(target: &Utf8Path) -> Result<()> {
+    crate::cli::require_root(false)?;
+    let sysroot = ostree::Sysroot::new(Some(&gio::File::for_path(target)));
+    sysroot.load(gio::Cancellable::NONE)?;
+    let deployments = sysroot.deployments();
+    // Verify we find a deployment
+    if deployments.is_empty() {
+        anyhow::bail!("Failed to find deployment in {target}");
+    }
+
+    // For now that's it! We expect to add more validation/postprocessing
+    // later, such as munging `etc/fstab` if needed. See
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

tests-integration/src/install.rs

@@ -104,6 +104,13 @@ pub(crate) fn run_alongside(image: &str, mut testargs: libtest_mimic::Arguments)
                 std::fs::write(&tmp_keys, b"ssh-ed25519 ABC0123 [email protected]")?;
                 cmd!(sh, "sudo {BASE_ARGS...} {target_args...} -v {tmp_keys}:/test_authorized_keys {image} bootc install to-filesystem {generic_inst_args...} --acknowledge-destructive --karg=foo=bar --replace=alongside --root-ssh-authorized-keys=/test_authorized_keys /target").run()?;
 
+                // Also test install finalize here
+                cmd!(
+                    sh,
+                    "sudo {BASE_ARGS...} {target_args...} {image} bootc install finalize /target"
+                )
+                .run()?;
+
                 generic_post_install_verification()?;
 
                 // Test kargs injected via CLI