From d8c8cf9b2b98b4f02e1e9c62c90dc751f88a12bf Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Fri, 13 Sep 2024 15:31:52 -0400
Subject: [PATCH] Move dracut code from cliwrap to initramfs module

Prep for handling kernel-install in a different way, where
we add a drop-in that is invoked by the existing binary instead
of intercepting it entirely.

No functional changes intended (yet).

Signed-off-by: Colin Walters <walters@verbum.org>
---
 rust/src/cliwrap/kernel_install.rs | 54 ++----------------------------
 rust/src/initramfs.rs              | 52 +++++++++++++++++++++++++++-
 2 files changed, 53 insertions(+), 53 deletions(-)

diff --git a/rust/src/cliwrap/kernel_install.rs b/rust/src/cliwrap/kernel_install.rs
index cc2a0077b0..5344094c34 100644
--- a/rust/src/cliwrap/kernel_install.rs
+++ b/rust/src/cliwrap/kernel_install.rs
@@ -1,15 +1,12 @@
 // If not running on container continue the current path.
 // SPDX-License-Identifier: Apache-2.0 OR MIT
-use crate::cliwrap;
 use crate::cliwrap::cliutil;
-use anyhow::{anyhow, Context, Result};
+use anyhow::Result;
 use camino::Utf8Path;
 use cap_std::fs::FileType;
 use cap_std::fs_utf8::Dir as Utf8Dir;
 use cap_std_ext::cap_std;
 use fn_error_context::context;
-use std::os::fd::AsRawFd;
-use std::process::Command;
 
 /// Primary entrypoint to running our wrapped `kernel-install` handling.
 #[context("rpm-ostree kernel-install wrapper")]
@@ -42,7 +39,7 @@ pub(crate) fn main(argv: &[&str]) -> Result<()> {
     }
     if let Some(k) = new_kernel {
         undo_systemctl_wrap()?;
-        run_dracut(&k)?;
+        crate::initramfs::run_dracut(&k)?;
         redo_systemctl_wrap()?;
     }
     Ok(())
@@ -63,50 +60,3 @@ fn redo_systemctl_wrap() -> Result<()> {
     bin_path.rename("systemctl.backup", &bin_path, "systemctl")?;
     Ok(())
 }
-
-#[context("Running dracut")]
-fn run_dracut(kernel_dir: &str) -> Result<()> {
-    let root_fs = Utf8Dir::open_ambient_dir("/", cap_std::ambient_authority())?;
-    let tmp_dir = tempfile::tempdir()?;
-    let tmp_initramfs_path = tmp_dir.path().join("initramfs.img");
-
-    let cliwrap_dracut = Utf8Path::new(cliwrap::CLIWRAP_DESTDIR).join("dracut");
-    let dracut_path = cliwrap_dracut
-        .exists()
-        .then(|| cliwrap_dracut)
-        .unwrap_or_else(|| Utf8Path::new("dracut").to_owned());
-    // If changing this, also look at changing rpmostree-kernel.cxx
-    let res = Command::new(dracut_path)
-        .args(&[
-            "--no-hostonly",
-            "--kver",
-            kernel_dir,
-            "--reproducible",
-            "-v",
-            "--add",
-            "ostree",
-            "-f",
-        ])
-        .arg(&tmp_initramfs_path)
-        .status()?;
-    if !res.success() {
-        return Err(anyhow!(
-            "Failed to generate initramfs (via dracut) for kernel: {kernel_dir}: {:?}",
-            res
-        ));
-    }
-    let f = std::fs::OpenOptions::new()
-        .write(true)
-        .append(true)
-        .open(&tmp_initramfs_path)?;
-    crate::initramfs::append_dracut_random_cpio(f.as_raw_fd())?;
-    drop(f);
-    let utf8_tmp_dir_path = Utf8Path::from_path(tmp_dir.path().strip_prefix("/")?)
-        .context("Error turning Path to Utf8Path")?;
-    root_fs.rename(
-        utf8_tmp_dir_path.join("initramfs.img"),
-        &root_fs,
-        (Utf8Path::new("lib/modules").join(kernel_dir)).join("initramfs.img"),
-    )?;
-    Ok(())
-}
diff --git a/rust/src/initramfs.rs b/rust/src/initramfs.rs
index 4b3c8135ad..465ef068f1 100644
--- a/rust/src/initramfs.rs
+++ b/rust/src/initramfs.rs
@@ -2,8 +2,9 @@
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
 use crate::cxxrsutil::*;
-use anyhow::{Context, Result};
+use anyhow::{anyhow, Context, Result};
 use camino::Utf8Path;
+use cap_std::fs_utf8::Dir as Utf8Dir;
 use cap_std::io_lifetimes::AsFilelike;
 use cap_std_ext::cap_std;
 use cap_std_ext::prelude::CapStdExtCommandExt;
@@ -13,9 +14,11 @@ use rustix::fd::BorrowedFd;
 use std::collections::BTreeSet;
 use std::collections::HashSet;
 use std::io::prelude::*;
+use std::os::fd::AsRawFd as _;
 use std::os::unix::io::IntoRawFd;
 use std::path::{Component, Path, PathBuf};
 use std::pin::Pin;
+use std::process::Command;
 use std::{fs, io};
 
 fn list_files_recurse<P: glib::IsA<gio::Cancellable>>(
@@ -181,6 +184,53 @@ pub(crate) fn initramfs_overlay_generate(
     Ok(r.into_raw_fd())
 }
 
+#[context("Running dracut")]
+pub(crate) fn run_dracut(kernel_dir: &str) -> Result<()> {
+    let root_fs = Utf8Dir::open_ambient_dir("/", cap_std::ambient_authority())?;
+    let tmp_dir = tempfile::tempdir()?;
+    let tmp_initramfs_path = tmp_dir.path().join("initramfs.img");
+
+    let cliwrap_dracut = Utf8Path::new(crate::cliwrap::CLIWRAP_DESTDIR).join("dracut");
+    let dracut_path = cliwrap_dracut
+        .exists()
+        .then(|| cliwrap_dracut)
+        .unwrap_or_else(|| Utf8Path::new("dracut").to_owned());
+    // If changing this, also look at changing rpmostree-kernel.cxx
+    let res = Command::new(dracut_path)
+        .args(&[
+            "--no-hostonly",
+            "--kver",
+            kernel_dir,
+            "--reproducible",
+            "-v",
+            "--add",
+            "ostree",
+            "-f",
+        ])
+        .arg(&tmp_initramfs_path)
+        .status()?;
+    if !res.success() {
+        return Err(anyhow!(
+            "Failed to generate initramfs (via dracut) for kernel: {kernel_dir}: {:?}",
+            res
+        ));
+    }
+    let f = std::fs::OpenOptions::new()
+        .write(true)
+        .append(true)
+        .open(&tmp_initramfs_path)?;
+    crate::initramfs::append_dracut_random_cpio(f.as_raw_fd())?;
+    drop(f);
+    let utf8_tmp_dir_path = Utf8Path::from_path(tmp_dir.path().strip_prefix("/")?)
+        .context("Error turning Path to Utf8Path")?;
+    root_fs.rename(
+        utf8_tmp_dir_path.join("initramfs.img"),
+        &root_fs,
+        (Utf8Path::new("lib/modules").join(kernel_dir)).join("initramfs.img"),
+    )?;
+    Ok(())
+}
+
 #[cfg(test)]
 mod test {
     use super::*;