treefile: Add no-initramfs: knob

docs/treefile.md

@@ -561,6 +561,8 @@ version of `rpm-ostree`.
    - `var`: `/opt` and `/usr/local` are symlinks to subdirectories in `/var`
      and are purely machine-local state.
    - `root`: These are plain directories; only use this with composefs enabled!
+ * `no-initramfs`: boolean, optional: If `true` don't run dracut to generate an
+   initramfs. Defaults to `false`.
 
 ### Kickstarts
 

rpmostree-cxxrs.cxx

@@ -1876,6 +1876,7 @@ struct Treefile final : public ::rust::Opaque
   bool may_require_local_assembly () const noexcept;
   bool has_any_packages () const noexcept;
   bool merge_treefile (::rust::Str treefile);
+  bool get_no_initramfs () const noexcept;
   ~Treefile () = delete;
 
 private:
@@ -2835,6 +2836,9 @@ extern "C"
   ::rust::repr::PtrLen
   rpmostreecxx$cxxbridge1$Treefile$merge_treefile (::rpmostreecxx::Treefile &self,
                                                    ::rust::Str treefile, bool *return$) noexcept;
+
+  bool
+  rpmostreecxx$cxxbridge1$Treefile$get_no_initramfs (::rpmostreecxx::Treefile const &self) noexcept;
   ::std::size_t rpmostreecxx$cxxbridge1$RepoPackage$operator$sizeof () noexcept;
   ::std::size_t rpmostreecxx$cxxbridge1$RepoPackage$operator$alignof () noexcept;
 
@@ -2885,6 +2889,9 @@ extern "C"
   rpmostreecxx$cxxbridge1$transaction_apply_live (::rpmostreecxx::OstreeSysroot const &sysroot,
                                                   ::rpmostreecxx::GVariant const &target) noexcept;
 
+  ::rust::repr::PtrLen
+  rpmostreecxx$cxxbridge1$normalize_etc_shadow (::std::int32_t rootfs_dfd) noexcept;
+
   ::rust::repr::PtrLen rpmostreecxx$cxxbridge1$prepare_rpm_layering (
       ::std::int32_t rootfs, ::std::int32_t merge_passwd_dir, bool *return$) noexcept;
 
@@ -5625,6 +5632,12 @@ Treefile::merge_treefile (::rust::Str treefile)
   return ::std::move (return$.value);
 }
 
+bool
+Treefile::get_no_initramfs () const noexcept
+{
+  return rpmostreecxx$cxxbridge1$Treefile$get_no_initramfs (*this);
+}
+
 ::std::size_t
 RepoPackage::layout::size () noexcept
 {
@@ -5770,6 +5783,16 @@ transaction_apply_live (::rpmostreecxx::OstreeSysroot const &sysroot,
     }
 }
 
+void
+normalize_etc_shadow (::std::int32_t rootfs_dfd)
+{
+  ::rust::repr::PtrLen error$ = rpmostreecxx$cxxbridge1$normalize_etc_shadow (rootfs_dfd);
+  if (error$.ptr)
+    {
+      throw ::rust::impl<::rust::Error>::error (error$);
+    }
+}
+
 bool
 prepare_rpm_layering (::std::int32_t rootfs, ::std::int32_t merge_passwd_dir)
 {

rpmostree-cxxrs.h

@@ -1653,6 +1653,7 @@ struct Treefile final : public ::rust::Opaque
   bool may_require_local_assembly () const noexcept;
   bool has_any_packages () const noexcept;
   bool merge_treefile (::rust::Str treefile);
+  bool get_no_initramfs () const noexcept;
   ~Treefile () = delete;
 
 private:
@@ -2083,6 +2084,8 @@ void applylive_sync_ref (::rpmostreecxx::OstreeSysroot const &sysroot);
 void transaction_apply_live (::rpmostreecxx::OstreeSysroot const &sysroot,
                              ::rpmostreecxx::GVariant const &target);
 
+void normalize_etc_shadow (::std::int32_t rootfs_dfd);
+
 bool prepare_rpm_layering (::std::int32_t rootfs, ::std::int32_t merge_passwd_dir);
 
 void complete_rpm_layering (::std::int32_t rootfs);

rust/src/lib.rs

@@ -690,6 +690,7 @@ pub mod ffi {
         fn may_require_local_assembly(&self) -> bool;
         fn has_any_packages(&self) -> bool;
         fn merge_treefile(&mut self, treefile: &str) -> Result<bool>;
+        fn get_no_initramfs(&self) -> bool;
     }
 
     // treefile.rs (split out from above to make &self nice to use)
@@ -738,6 +739,11 @@ pub mod ffi {
         fn transaction_apply_live(sysroot: &OstreeSysroot, target: &GVariant) -> Result<()>;
     }
 
+    // normalization.rs
+    extern "Rust" {
+        fn normalize_etc_shadow(rootfs_dfd: i32) -> Result<()>;
+    }
+
     // passwd.rs
     extern "Rust" {
         fn prepare_rpm_layering(rootfs: i32, merge_passwd_dir: i32) -> Result<bool>;
@@ -1018,6 +1024,7 @@ mod live;
 pub(crate) use self::live::*;
 mod nameservice;
 mod normalization;
+use normalization::*;
 mod origin;
 mod ostree_prepareroot;
 pub(crate) use self::origin::*;

rust/src/normalization.rs

@@ -6,6 +6,8 @@
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
 use crate::bwrap::Bubblewrap;
+use crate::cxxrsutil::*;
+use crate::ffiutil;
 use crate::nameservice::shadow::parse_shadow_content;
 use anyhow::{anyhow, Context, Result};
 use cap_std::fs::OpenOptionsExt;
@@ -30,7 +32,8 @@ pub(crate) fn source_date_epoch_raw() -> Option<String> {
 }
 
 #[context("Rewriting /etc/shadow to remove lstchg field")]
-pub(crate) fn normalize_etc_shadow(rootfs: &Dir) -> Result<()> {
+pub(crate) fn normalize_etc_shadow(rootfs_dfd: i32) -> CxxResult<()> {
+    let rootfs = unsafe { ffiutil::ffi_dirfd(rootfs_dfd)? };
     // Read in existing entries.
     let mut openopts = OpenOptions::new();
     openopts.create(true).read(true).write(true).mode(0o400);

rust/src/passwd.rs

@@ -89,7 +89,7 @@ pub fn complete_rpm_layering(rootfs_dfd: i32) -> CxxResult<()> {
     // /etc/shadow ends up with a timestamp in it thanks to the `lstchg`
     // field. This can be made empty safely, especially for accounts that
     // are locked.
-    normalization::normalize_etc_shadow(&rootfs)?;
+    normalization::normalize_etc_shadow(rootfs_dfd)?;
 
     Ok(())
 }

rust/src/treefile.rs

@@ -482,7 +482,8 @@ fn treefile_merge(dest: &mut TreeComposeConfig, src: &mut TreeComposeConfig) {
         check_passwd,
         check_groups,
         postprocess_script,
-        rpmdb_normalize
+        rpmdb_normalize,
+        no_initramfs
     );
     merge_hashsets!(ignore_removed_groups, ignore_removed_users);
     merge_maps!(add_commit_metadata, variables, metadata, repovars);
@@ -1856,6 +1857,10 @@ impl Treefile {
         derived
     }
 
+    pub(crate) fn get_no_initramfs(&self) -> bool {
+        self.parsed.base.no_initramfs.unwrap_or_default()
+    }
+
     pub(crate) fn set_initramfs_regenerate(&mut self, enabled: bool, args: Vec<String>) {
         if !enabled {
             // implicitly leaves empty if already empty
@@ -2609,6 +2614,8 @@ pub(crate) struct BaseComposeConfigFields {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub(crate) initramfs_args: Option<Vec<String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    pub(crate) no_initramfs: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub(crate) readonly_executables: Option<bool>,
 
     // Tree layout options

src/libpriv/rpmostree-kernel.cxx

@@ -398,10 +398,17 @@ rpmostree_finalize_kernel (int rootfs_dfd, const char *bootdir, const char *kver
     }
   else
     {
-      /* we're not replacing the initramfs; use built-in one */
-      if (!_rpmostree_util_update_checksum_from_file (boot_checksum, rootfs_dfd,
-                                                      initramfs_modules_path, cancellable, error))
+      /* We're not replacing the initramfs; use built-in one if it exists */
+      if (!glnx_fstatat_allow_noent (rootfs_dfd, initramfs_modules_path, NULL, AT_SYMLINK_NOFOLLOW,
+                                     error))
         return FALSE;
+      if (errno == 0)
+        {
+          /* It exists, update the checksum */
+          if (!_rpmostree_util_update_checksum_from_file (
+                  boot_checksum, rootfs_dfd, initramfs_modules_path, cancellable, error))
+            return FALSE;
+        }
     }
 
   const char *boot_checksum_str = g_checksum_get_string (boot_checksum);

src/libpriv/rpmostree-postprocess.cxx

@@ -80,6 +80,48 @@ rename_if_exists (int src_dfd, const char *from, int dest_dfd, const char *to, G
   return TRUE;
 }
 
+static gboolean
+run_dracut (int rootfs_dfd, rpmostreecxx::Treefile &treefile, GLnxTmpfile *initramfs_tmpf,
+            const char *kver, GCancellable *cancellable, GError **error)
+{
+  /* Run dracut with our chosen arguments (commonly at least --no-hostonly) */
+  g_autoptr (GPtrArray) dracut_argv = g_ptr_array_new ();
+  rust::Vec<rust::String> initramfs_args = treefile.get_initramfs_args ();
+  if (!initramfs_args.empty ())
+    {
+      for (auto &arg : initramfs_args)
+        g_ptr_array_add (dracut_argv, (void *)arg.c_str ());
+    }
+  else
+    {
+      /* Default to this for treecomposes */
+      g_ptr_array_add (dracut_argv, (char *)"--no-hostonly");
+    }
+  g_ptr_array_add (dracut_argv, NULL);
+
+  /* We use a tmpdir under the target root since dracut currently tries to copy
+   * xattrs, including e.g. user.ostreemeta, which can't be copied to tmpfs.
+   */
+  {
+    g_auto (GLnxTmpDir) dracut_host_tmpd = {
+      0,
+    };
+    if (!glnx_mkdtempat (rootfs_dfd, "rpmostree-dracut.XXXXXX", 0700, &dracut_host_tmpd, error))
+      return FALSE;
+    if (!rpmostree_run_dracut (rootfs_dfd, (const char *const *)dracut_argv->pdata, kver, NULL,
+                               FALSE, &dracut_host_tmpd, initramfs_tmpf, cancellable, error))
+      return FALSE;
+    /* No reason to have the initramfs not be world-readable since
+     * it's server-side generated and shouldn't contain any secrets.
+     * https://github.com/coreos/coreos-assembler/pull/372#issuecomment-467620937
+     */
+    if (!glnx_fchmod (initramfs_tmpf->fd, 0644, error))
+      return FALSE;
+  }
+
+  return TRUE;
+}
+
 /* Handle the kernel/initramfs, which can be in at least 2 different places:
  *  - /boot (CentOS, Fedora treecompose before we suppressed kernel.spec's %posttrans)
  *  - /usr/lib/modules (Fedora treecompose without kernel.spec's %posttrans)
@@ -195,43 +237,19 @@ process_kernel_and_initramfs (int rootfs_dfd, rpmostreecxx::Treefile &treefile,
       (void)unlinkat (rootfs_dfd, "usr/etc/machine-id", 0);
     }
 
-  /* Run dracut with our chosen arguments (commonly at least --no-hostonly) */
-  g_autoptr (GPtrArray) dracut_argv = g_ptr_array_new ();
-  rust::Vec<rust::String> initramfs_args = treefile.get_initramfs_args ();
-  if (!initramfs_args.empty ())
-    {
-      for (auto &arg : initramfs_args)
-        g_ptr_array_add (dracut_argv, (void *)arg.c_str ());
-    }
-  else
-    {
-      /* Default to this for treecomposes */
-      g_ptr_array_add (dracut_argv, (char *)"--no-hostonly");
-    }
-  g_ptr_array_add (dracut_argv, NULL);
-
   g_auto (GLnxTmpfile) initramfs_tmpf = {
     0,
   };
-  /* We use a tmpdir under the target root since dracut currently tries to copy
-   * xattrs, including e.g. user.ostreemeta, which can't be copied to tmpfs.
+  if (!treefile.get_no_initramfs ())
+    {
+      if (!run_dracut (rootfs_dfd, treefile, &initramfs_tmpf, kver, cancellable, error))
+        return FALSE;
+    }
+
+  /* Always normalize etc shadow. If we called run_dracut this may
+   * have already been done but it's OK since it's idempotent.
    */
-  {
-    g_auto (GLnxTmpDir) dracut_host_tmpd = {
-      0,
-    };
-    if (!glnx_mkdtempat (rootfs_dfd, "rpmostree-dracut.XXXXXX", 0700, &dracut_host_tmpd, error))
-      return FALSE;
-    if (!rpmostree_run_dracut (rootfs_dfd, (const char *const *)dracut_argv->pdata, kver, NULL,
-                               FALSE, &dracut_host_tmpd, &initramfs_tmpf, cancellable, error))
-      return FALSE;
-    /* No reason to have the initramfs not be world-readable since
-     * it's server-side generated and shouldn't contain any secrets.
-     * https://github.com/coreos/coreos-assembler/pull/372#issuecomment-467620937
-     */
-    if (!glnx_fchmod (initramfs_tmpf.fd, 0644, error))
-      return FALSE;
-  }
+  ROSCXX_TRY (normalize_etc_shadow (rootfs_dfd), error);
 
   /* We always tell rpmostree_finalize_kernel() to skip /boot, since we'll do a
    * full hardlink pass if needed after that for the kernel + bootloader data.

tests/compose/test-no-initramfs.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -xeuo pipefail
+
+dn=$(cd "$(dirname "$0")" && pwd)
+# shellcheck source=libcomposetest.sh
+. "${dn}/libcomposetest.sh"
+
+treefile_set "no-initramfs" 'True'
+runcompose
+echo "ok compose"
+
+commit=$(jq -r '.["ostree-commit"]' < compose.json)
+ostree --repo=${repo:?} ls -R ${commit} usr/lib/modules > ls.txt
+assert_not_file_has_content ls.txt '/usr/lib/modules/.*/initramfs.img$'
+echo "ok no initramfs"