Fix the issue of losing nf_conntrace* values after a reboot.

Loading ip_vs module before setting nf_conntrace_* opts.

Story: 2010795
Task: 48247
Change-Id: Ie4763e97b1414e9871f222c20efd0f532b3dfc9f

Author: wchy1001

octavia/amphorae/backends/agent/api_server/templates/amphora-netns.systemd.j2

@@ -10,15 +10,15 @@ RemainAfterExit=yes
 ExecStart=-/sbin/ip netns add {{ amphora_nsname }}
 # Load the system sysctl into the new namespace
 ExecStart=-/sbin/ip netns exec {{ amphora_nsname }} sysctl --system
+# Enable kernel module ip_vs for lvs function in amphora network namespace
+ExecStart=-/sbin/ip netns exec {{ amphora_nsname }} modprobe ip_vs
 # Set nf_conntrack_buckets sysctl in the main namespace (nf_conntrack_buckets
 # cannot be set in another net namespace, but its value is inherited from the
 # main namespace)
 ExecStart=-/sbin/sysctl -w net.netfilter.nf_conntrack_buckets=125000
 # Update conntrack table sizes using the formula for the default values
 ExecStart=-/sbin/sysctl -w net.netfilter.nf_conntrack_max=125000
 ExecStart=-/sbin/sysctl -w net.netfilter.nf_conntrack_expect_max=488
-# Enable kernel module ip_vs for lvs function in amphora network namespace
-ExecStart=-/sbin/ip netns exec {{ amphora_nsname }} modprobe ip_vs
 # Enable ip_forward and conntrack kernel configuration
 ExecStart=-/sbin/ip netns exec {{ amphora_nsname }} sysctl -w net.ipv4.ip_forward=1
 ExecStart=-/sbin/ip netns exec {{ amphora_nsname }} sysctl -w net.ipv4.vs.conntrack=1

releasenotes/notes/load-ipvs-before-setting-opts-c5b2f0871bc38c27.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fix the issue where nf_conntrack* opts values are lost after rebooting the Amphora VM.
+    more details `Story 2010795 <https://storyboard.openstack.org/#!/story/2010795>`__