systemd: arrange for volatile /etc/resolv.conf

On sysvinit systems, volatiles is configured to make /etc/resolv.conf symlink
to a file in a volatile path, which lets us write to /etc/resolv.conf for
read-only-rootfs. For systemd, this isn't set up unless we enable
systemd-resolved, which we don't by default. When it's not enabled, create the
/etc/resolv.conf symlink and ensure the volatile path is created on boot with
tmpfiles.d.

(From OE-Core rev: 7f087f161e8942bcd35f88999dfca418f01cd7fa)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/meta/recipes-core/systemd/systemd_228.bb b/meta/recipes-core/systemd/systemd_228.bb
index df8813ac42..aa2e846b69 100644
--- a/meta/recipes-core/systemd/systemd_228.bb
+++ b/meta/recipes-core/systemd/systemd_228.bb
@@ -203,6 +203,13 @@ do_install() {
         if [ -s ${D}${exec_prefix}/lib/tmpfiles.d/systemd.conf ]; then
                 ${@bb.utils.contains('PACKAGECONFIG', 'networkd', ':', 'sed -i -e "\$ad /run/systemd/netif/links 0755 root root -" ${D}${exec_prefix}/lib/tmpfiles.d/systemd.conf', d)}
         fi
+        if ! ${@bb.utils.contains('PACKAGECONFIG', 'resolved', 'true', 'false', d)}; then
+                # if resolved is disabled, it won't handle the link of resolv.conf, so
+                # set it up ourselves
+                ln -s ../run/resolv.conf ${D}${sysconfdir}/resolv.conf
+                echo 'L! ${sysconfdir}/resolv.conf - - - - ../run/resolv.conf' >>${D}${exec_prefix}/lib/tmpfiles.d/etc.conf
+                echo 'f /run/resolv.conf 0644 root root' >>${D}${exec_prefix}/lib/tmpfiles.d/systemd.conf
+        fi
         install -Dm 0755 ${S}/src/systemctl/systemd-sysv-install.SKELETON ${D}${systemd_unitdir}/systemd-sysv-install
 }
 
@@ -297,6 +304,7 @@ FILES_${PN} = " ${base_bindir}/* \
                 ${sysconfdir}/tmpfiles.d/ \
                 ${sysconfdir}/xdg/ \
                 ${sysconfdir}/init.d/README \
+                ${sysconfdir}/resolv.conf \
                 ${rootlibexecdir}/systemd/* \
                 ${systemd_unitdir}/* \
                 ${base_libdir}/security/*.so \