build-sys: Enable rhsm feature on rhel-like systems by default

The Dockerfile right now doesn't build an RPM, so this
ensures the two build systems match. We should probably
also change the RPM to use this Makefile.

Motivated by accidentally merging a change that breaks
with the feature on.

Signed-off-by: Colin Walters <[email protected]>

Author: cgwalters

Makefile

@@ -4,8 +4,14 @@ SOURCE_DATE_EPOCH ?= $(shell git log -1 --pretty=%ct)
 # https://reproducible-builds.org/docs/archives/
 TAR_REPRODUCIBLE = tar --mtime="@${SOURCE_DATE_EPOCH}" --sort=name --owner=0 --group=0 --numeric-owner --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime
 
+# Enable rhsm if we detect the build environment is RHEL-like.
+# 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 ?= $(shell . /usr/lib/os-release; if [[ "$$ID_LIKE" == *"rhel"* ]]; then echo rhsm; fi)
+
 all:
-	cargo build --release
+	cargo build --release --features "$(CARGO_FEATURES)"
 
 install:
 	install -D -m 0755 -t $(DESTDIR)$(prefix)/bin target/release/bootc