Make the neutron-haproxy-wrapper compatible with haproxy 1.8

Currently we spawn haproxy with: ip netns exec ${NETNS}
/usr/sbin/haproxy -Ds $ARGS.

The reason for that was that with -Ds we keep a process in the foreground:
-Ds Start in systemd daemon mode, keeping a process in foreground.

Since haproxy 1.8 removed the
haproxy-systemd-wrapper it also removed the '-Ds' option. In order to
keep things running in the foreground we can just switch to using '-Ws'
Which is the multiworker mode with systemd support which keeps the
process in the foregroud.

This commit keeps backward compatibility with current HAProxy to ease
the transition to new HAProxy.

Co-Authored-By: Damien Ciabrini <dciabrin@redhat.com>

Change-Id: Ia914de9b3438976d24bf09ad680e806a0fb6644e

spec/defines/tripleo_profile_base_neutron_wrappers_haproxy_spec.rb

@@ -52,7 +52,7 @@ describe 'tripleo::profile::base::neutron::wrappers::haproxy' do
           /set -x/
         )
         is_expected.to contain_file('/usr/local/bin/haproxy').with_content(
-          /CMD="ip netns exec.*\/usr\/sbin\/haproxy -Ds/
+          /.*haproxy -Ds.*haproxy -Ws.*/
         )
       end
     end
@@ -78,7 +78,7 @@ describe 'tripleo::profile::base::neutron::wrappers::haproxy' do
           /^NAME=neutron-haproxy-/
         )
         is_expected.to contain_file('/usr/local/bin/haproxy').with_content(
-          /CMD='\/usr\/sbin\/haproxy -Ds'/
+          /.*haproxy -Ds.*haproxy -Ws.*/
         )
       end
     end

templates/neutron/haproxy.epp

@@ -19,12 +19,13 @@ ARGS="$@"
 #   --dhcp-hostsfile=/var/lib/neutron/dhcp/317716b8-919a-4a6f-8db1-78128ec3b100/host ...
 NETNS=$(ip netns identify)
 NAME=neutron-haproxy-${NETNS}
+HAPROXY_CMD='$(if [ -f /usr/sbin/haproxy-systemd-wrapper ]; then echo "/usr/sbin/haproxy -Ds"; else echo "/usr/sbin/haproxy -Ws"; fi)'
 <%- if $container_cli == 'docker' { -%>
 CLI='docker'
-CMD="ip netns exec ${NETNS} /usr/sbin/haproxy -Ds"
+CMD="ip netns exec ${NETNS} "'$HAPROXY'
 <%- } elsif $container_cli == 'podman' { -%>
 CLI="nsenter --net=/run/netns/${NETNS} --preserve-credentials -m -t 1 podman"
-CMD='/usr/sbin/haproxy -Ds'
+CMD='$HAPROXY'
 <%- } else { -%>
 CLI='echo noop'
 CMD='echo noop'
@@ -54,4 +55,4 @@ $CLI run --detach \
      -u root \
      --name $NAME \
      <%=$image_name%> \
-     $CMD $ARGS
+     /bin/bash -c "HAPROXY=\"$HAPROXY_CMD\"; exec $CMD $ARGS"