Add a Rust feature systemd-supports-mount-extra

Set the feature on if detect rhel >= 9.6, also centos >= 9 and
fedora > 41

Refer to Colin's pointer #1752 (comment)

Author: HuijingHei

Makefile

@@ -29,7 +29,24 @@ prefix ?= /usr
 # We may in the future also want to include Fedora+derivatives as
 # the code is really tiny.
 # (Note we should also make installation of the units conditional on the rhsm feature)
-CARGO_FEATURES_DEFAULT ?= $(shell . /usr/lib/os-release; if echo "$$ID_LIKE" |grep -qF rhel; then echo rhsm; fi)
+# Enable systemd-supports-mount-extra for RHEL >= 9.6 or non-RHEL systems (Fedora, etc.)
+CARGO_FEATURES_DEFAULT ?= $(shell \
+	. /usr/lib/os-release; \
+	features=""; \
+	if echo "$$ID_LIKE" |grep -qF rhel; then \
+		features="rhsm"; \
+	fi; \
+	if [ "$$ID" != "rhel" ] || [ -z "$$VERSION_ID" ]; then \
+		features="$$features systemd-supports-mount-extra"; \
+	else \
+		major=$${VERSION_ID%%.*}; \
+		minor=$${VERSION_ID#*.}; \
+		if [ "$$major" -gt 9 ] || ([ "$$major" -eq 9 ] && [ "$$minor" -ge 6 ]); then \
+			features="$$features systemd-supports-mount-extra"; \
+		fi; \
+	fi; \
+	echo "$$features" | sed 's/^ //'; \
+)
 # You can set this to override all cargo features, including the defaults
 CARGO_FEATURES ?= $(CARGO_FEATURES_DEFAULT)
 

contrib/packaging/bootc.spec

@@ -12,6 +12,13 @@
     %bcond_with rhsm
 %endif
 
+# systemd.mount-extra support requires RHEL >= 9.6
+%if 0%{?rhel} < 9 || (0%{?rhel} == 9 && 0%{?rhel_minor_version} < 6)
+    %bcond_with systemd_mount_extra
+%else
+    %bcond_without systemd_mount_extra
+%endif
+
 %global rust_minor %(rustc --version | cut -f2 -d" " | cut -f2 -d".")
 
 # https://github.com/bootc-dev/bootc/issues/1640
@@ -127,13 +134,13 @@ make manpages
 # Build all binaries
 %if 0%{?container_build}
 # Container build: use cargo directly with cached dependencies to avoid RPM macro overhead
-cargo build -j%{_smp_build_ncpus} --release %{?with_rhsm:--features rhsm} --bins
+cargo build -j%{_smp_build_ncpus} --release %{?with_rhsm:--features rhsm}%{?with_systemd_mount_extra:,systemd-supports-mount-extra} --bins
 %else
 # Non-container build: use RPM macros for proper dependency tracking
 %if %new_cargo_macros
-    %cargo_build %{?with_rhsm:-f rhsm} -- --bins
+    %cargo_build %{?with_rhsm:-f rhsm} %{?with_systemd_mount_extra:-f systemd-supports-mount-extra} -- --bins
 %else
-    %cargo_build %{?with_rhsm:--features rhsm} -- --bins
+    %cargo_build %{?with_rhsm:--features rhsm}%{?with_systemd_mount_extra:,systemd-supports-mount-extra} -- --bins
 %endif
 %endif
 

crates/lib/Cargo.toml

@@ -82,6 +82,9 @@ install-to-disk = []
 # This featuares enables `bootc internals publish-rhsm-facts` to integrate with
 # Red Hat Subscription Manager
 rhsm = []
+# This feature enables support for systemd.mount-extra kernel argument,
+# which requires RHEL >= 9.6
+systemd-supports-mount-extra = []
 # Implementation detail of man page generation.
 docgen = ["clap_mangen"]
 

crates/lib/src/install.rs

@@ -983,6 +983,7 @@ async fn install_container(
     // For seperate /boot filesystem, the better workaround is
     // to inject kernel arguments during installation.
     // See discussion in https://github.com/bootc-dev/bootc/issues/1388
+    #[cfg(feature = "systemd-supports-mount-extra")]
     if let Some(boot) = root_setup.boot.as_ref() {
         if !boot.source.is_empty() {
             let mount_extra = format!(