[PATCH pve-manager v2 15/16] sdn: bring the dhcp backends up at boot before the guests start

[Hannes Laimer <h.laimer@proxmox.com>]

The eBPF DHCP responder keeps its state in bpffs and under /run, both
gone after a reboot. Without pending SDN changes nothing loaded it again
until the first guest plugged an interface. Every guest starting
alongside then queued on that first plug's full pass, and one waiting
longer than the lock bound started without the responder. The SDN commit
runs on every boot, so it brings the backends up first, whether SDN
changes are pending or not. Its unit is ordered after the cluster
filesystem it reads, and the guests and the HA local resource manager
are ordered behind it. A node without quorum at boot holds them until it
has one, the guests waited for that anyway. The commit's own work holds
them as well, so the resource manager now waits with the guests.

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
 bin/pve-sdn-commit              | 3 +++
 services/pve-sdn-commit.service | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/bin/pve-sdn-commit b/bin/pve-sdn-commit
index aa7e9b29..ed2d6935 100644
--- a/bin/pve-sdn-commit
+++ b/bin/pve-sdn-commit
@@ -96,6 +96,9 @@ sub sdn_changed {
     return fabrics_changed();
 }
 
+# the dhcp backends bring back what a reboot took, pending changes or not
+PVE::Network::SDN::Dhcp::boot();
+
 if (!sdn_changed()) {
     print "No changes to SDN configuration detected, skipping reload\n";
     exit 0;
diff --git a/services/pve-sdn-commit.service b/services/pve-sdn-commit.service
index ff723725..c96a4b55 100644
--- a/services/pve-sdn-commit.service
+++ b/services/pve-sdn-commit.service
@@ -2,7 +2,8 @@
 Description=Commit Proxmox VE SDN changes
 DefaultDependencies=no
 Wants=pve-cluster.service network.target
-After=frr.service network.target corosync.service
+After=frr.service network.target corosync.service pve-cluster.service
+Before=pve-guests.service pve-ha-lrm.service
 
 [Service]
 ExecStart=/usr/share/pve-manager/helpers/pve-sdn-commit
-- 
2.47.3