Use a shared const and helpers for run/ostree-booted

Just a code cleanup.

Closes: containers#934
Signed-off-by: Colin Walters <[email protected]>

lib/src/cli.rs

@@ -17,6 +17,7 @@ use fn_error_context::context;
 use ostree::gio;
 use ostree_container::store::PrepareResult;
 use ostree_ext::container as ostree_container;
+use ostree_ext::container_utils::ostree_booted;
 use ostree_ext::keyfileext::KeyFileExt;
 use ostree_ext::ostree;
 use schemars::schema_for;
@@ -611,9 +612,10 @@ fn prepare_for_write() -> Result<()> {
     if ostree_ext::container_utils::running_in_container() {
         anyhow::bail!("Detected container; this command requires a booted host system.");
     }
-    if !std::path::Path::new("/run/ostree-booted").exists() {
-        anyhow::bail!("This command requires an ostree-booted host system");
-    }
+    anyhow::ensure!(
+        ostree_booted()?,
+        "This command requires an ostree-booted host system"
+    );
     crate::cli::require_root()?;
     ensure_self_unshared_mount_namespace()?;
     if crate::lsm::selinux_enabled()? && !crate::lsm::selinux_ensure_install()? {

lib/src/generator.rs

@@ -4,6 +4,7 @@ use anyhow::{Context, Result};
 use cap_std::fs::Dir;
 use cap_std_ext::{cap_std, dirext::CapStdExtDirExt};
 use fn_error_context::context;
+use ostree_ext::container_utils::is_ostree_booted_in;
 use rustix::{fd::AsFd, fs::StatVfsMountFlags};
 
 const EDIT_UNIT: &str = "bootc-fstab-edit.service";
@@ -14,7 +15,7 @@ pub(crate) const BOOTC_EDITED_STAMP: &str = "Updated by bootc-fstab-edit.service
 #[context("bootc generator")]
 pub(crate) fn fstab_generator_impl(root: &Dir, unit_dir: &Dir) -> Result<bool> {
     // Do nothing if not ostree-booted
-    if !root.try_exists("run/ostree-booted")? {
+    if !is_ostree_booted_in(root)? {
         return Ok(false);
     }
 
@@ -105,31 +106,37 @@ fn test_generator_no_fstab() -> Result<()> {
     Ok(())
 }
 
-#[test]
-fn test_generator_fstab() -> Result<()> {
-    let tempdir = fixture()?;
-    let unit_dir = &tempdir.open_dir("run/systemd/system")?;
-    // Should still be a no-op
-    tempdir.atomic_write("etc/fstab", "# Some dummy fstab")?;
-    fstab_generator_impl(&tempdir, &unit_dir).unwrap();
-    assert_eq!(unit_dir.entries()?.count(), 0);
-
-    // Also a no-op, not booted via ostree
-    tempdir.atomic_write("etc/fstab", &format!("# {FSTAB_ANACONDA_STAMP}"))?;
-    fstab_generator_impl(&tempdir, &unit_dir).unwrap();
-    assert_eq!(unit_dir.entries()?.count(), 0);
-
-    // Now it should generate
-    tempdir.atomic_write("run/ostree-booted", "ostree booted")?;
-    fstab_generator_impl(&tempdir, &unit_dir).unwrap();
-    assert_eq!(unit_dir.entries()?.count(), 2);
-
-    Ok(())
-}
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use ostree_ext::container_utils::OSTREE_BOOTED;
+
+    #[test]
+    fn test_generator_fstab() -> Result<()> {
+        let tempdir = fixture()?;
+        let unit_dir = &tempdir.open_dir("run/systemd/system")?;
+        // Should still be a no-op
+        tempdir.atomic_write("etc/fstab", "# Some dummy fstab")?;
+        fstab_generator_impl(&tempdir, &unit_dir).unwrap();
+        assert_eq!(unit_dir.entries()?.count(), 0);
+
+        // Also a no-op, not booted via ostree
+        tempdir.atomic_write("etc/fstab", &format!("# {FSTAB_ANACONDA_STAMP}"))?;
+        fstab_generator_impl(&tempdir, &unit_dir).unwrap();
+        assert_eq!(unit_dir.entries()?.count(), 0);
+
+        // Now it should generate
+        tempdir.atomic_write(OSTREE_BOOTED, "ostree booted")?;
+        fstab_generator_impl(&tempdir, &unit_dir).unwrap();
+        assert_eq!(unit_dir.entries()?.count(), 2);
+
+        Ok(())
+    }
 
-#[test]
-fn test_generator_fstab_idempotent() -> Result<()> {
-    let anaconda_fstab = indoc::indoc! { "
+    #[test]
+    fn test_generator_fstab_idempotent() -> Result<()> {
+        let anaconda_fstab = indoc::indoc! { "
 #
 # /etc/fstab
 # Created by anaconda on Tue Mar 19 12:24:29 2024
@@ -144,14 +151,15 @@ fn test_generator_fstab_idempotent() -> Result<()> {
 UUID=715be2b7-c458-49f2-acec-b2fdb53d9089 /                       xfs     ro              0 0
 UUID=341c4712-54e8-4839-8020-d94073b1dc8b /boot                   xfs     defaults        0 0
 " };
-    let tempdir = fixture()?;
-    let unit_dir = &tempdir.open_dir("run/systemd/system")?;
+        let tempdir = fixture()?;
+        let unit_dir = &tempdir.open_dir("run/systemd/system")?;
 
-    tempdir.atomic_write("etc/fstab", anaconda_fstab)?;
-    tempdir.atomic_write("run/ostree-booted", "ostree booted")?;
-    let updated = fstab_generator_impl(&tempdir, &unit_dir).unwrap();
-    assert!(!updated);
-    assert_eq!(unit_dir.entries()?.count(), 0);
+        tempdir.atomic_write("etc/fstab", anaconda_fstab)?;
+        tempdir.atomic_write(OSTREE_BOOTED, "ostree booted")?;
+        let updated = fstab_generator_impl(&tempdir, &unit_dir).unwrap();
+        assert!(!updated);
+        assert_eq!(unit_dir.entries()?.count(), 0);
 
-    Ok(())
+        Ok(())
+    }
 }

lib/src/status.rs

@@ -5,11 +5,11 @@ use std::io::Read;
 use std::io::Write;
 
 use anyhow::{Context, Result};
-use camino::Utf8Path;
 use fn_error_context::context;
 use ostree::glib;
 use ostree_container::OstreeImageReference;
 use ostree_ext::container as ostree_container;
+use ostree_ext::container_utils::ostree_booted;
 use ostree_ext::keyfileext::KeyFileExt;
 use ostree_ext::oci_spec;
 use ostree_ext::ostree;
@@ -294,7 +294,7 @@ pub(crate) async fn status(opts: super::cli::StatusOpts) -> Result<()> {
         0 | 1 => {}
         o => anyhow::bail!("Unsupported format version: {o}"),
     };
-    let host = if !Utf8Path::new("/run/ostree-booted").try_exists()? {
+    let host = if !ostree_booted()? {
         Default::default()
     } else {
         let sysroot = super::cli::get_storage().await?;

ostree-ext/src/container_utils.rs

@@ -1,11 +1,18 @@
 //! Helpers for interacting with containers at runtime.
 
-use crate::keyfileext::KeyFileExt;
-use anyhow::Result;
-use ostree::glib;
+use std::io;
 use std::io::Read;
 use std::path::Path;
 
+use anyhow::Result;
+use ocidir::cap_std::fs::Dir;
+use ostree::glib;
+
+use crate::keyfileext::KeyFileExt;
+
+/// The relative path to the stamp file which signals this is an ostree-booted system.
+pub const OSTREE_BOOTED: &str = "run/ostree-booted";
+
 // See https://github.com/coreos/rpm-ostree/pull/3285#issuecomment-999101477
 // For compatibility with older ostree, we stick this in /sysroot where
 // it will be ignored.
@@ -64,6 +71,17 @@ pub fn is_bare_split_xattrs() -> Result<bool> {
     }
 }
 
+/// Returns true if the system appears to have been booted via ostree.
+/// This accesses global state in /run.
+pub fn ostree_booted() -> io::Result<bool> {
+    Path::new(&format!("/{OSTREE_BOOTED}")).try_exists()
+}
+
+/// Returns true if the target root appears to have been booted via ostree.
+pub fn is_ostree_booted_in(rootfs: &Dir) -> io::Result<bool> {
+    rootfs.try_exists(OSTREE_BOOTED)
+}
+
 /// Returns `true` if the current booted filesystem appears to be an ostree-native container.
 ///
 /// This just invokes [`is_bare_split_xattrs`] and [`running_in_container`].
@@ -73,8 +91,7 @@ pub fn is_ostree_container() -> Result<bool> {
     // If we have a container-ostree repo format, then we'll assume we're
     // running in a container unless there's strong evidence not (we detect
     // we're part of a systemd unit or are in a booted ostree system).
-    let maybe_container = running_in_container()
-        || (!running_in_systemd && !Path::new("/run/ostree-booted").exists());
+    let maybe_container = running_in_container() || (!running_in_systemd && !ostree_booted()?);
     Ok(is_container_ostree && maybe_container)
 }
 

ostree-ext/src/integrationtest.rs

@@ -2,7 +2,7 @@
 
 use std::path::Path;
 
-use crate::container_utils::is_ostree_container;
+use crate::container_utils::{is_ostree_container, ostree_booted};
 use anyhow::{anyhow, Context, Result};
 use camino::Utf8Path;
 use cap_std::fs::Dir;
@@ -21,7 +21,7 @@ use xshell::cmd;
 pub(crate) fn detectenv() -> Result<&'static str> {
     let r = if is_ostree_container()? {
         "ostree-container"
-    } else if Path::new("/run/ostree-booted").exists() {
+    } else if ostree_booted()? {
         "ostree"
     } else if crate::container_utils::running_in_container() {
         "container"