[OE-Core][PATCH v2] packagegroup-base: Add option to set zeroconf provider

[Alex Kiernan <alex.kiernan@gmail.com>]

avahi, systemd-resolved and mDNSResponder (in meta-networking) can all
provide Zeroconf services. Add a `ZEROCONF_DAEMON` option to select
which of these will provide service via packagegroup-base-zeroconf.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
---
 meta/recipes-core/packagegroups/packagegroup-base.bb | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/meta/recipes-core/packagegroups/packagegroup-base.bb b/meta/recipes-core/packagegroups/packagegroup-base.bb
index cb9d1f07af51..ac450fbdc9a7 100644
--- a/meta/recipes-core/packagegroups/packagegroup-base.bb
+++ b/meta/recipes-core/packagegroups/packagegroup-base.bb
@@ -312,11 +312,14 @@ RDEPENDS:packagegroup-base-nfs = "\
 RRECOMMENDS:packagegroup-base-nfs = "\
     kernel-module-nfs "
 
+# Choose 'avahi-daemon', 'mdns' or 'systemd-resolved' as zeroconf-daemon
+ZEROCONF_DAEMON ??= "${@bb.utils.contains('DISTRO_FEATURES', 'systemd-resolved', 'systemd-resolved', 'avahi-daemon', d)}"
 SUMMARY:packagegroup-base-zeroconf = "Zeroconf support"
 RDEPENDS:packagegroup-base-zeroconf = "\
-    avahi-daemon"
+    ${@ '' if d.getVar('ZEROCONF_DAEMON') == 'systemd-resolved' else d.getVar('ZEROCONF_DAEMON')} \
+    "
 RDEPENDS:packagegroup-base-zeroconf:append:libc-glibc = "\
-    libnss-mdns \
+    ${@ {'mdns':'mdns-libnss-mdns','avahi-daemon':'avahi-libnss-mdns','systemd-resolved':''}[d.getVar('ZEROCONF_DAEMON')]} \
     "
 
 SUMMARY:packagegroup-base-ipv6 = "IPv6 support"