The expected binary is missing.
DEBUG:/usr/local/bin/kolla_mesos_start:Name is: neutron.conf.j2, Item is: {u'dest': u'/etc/neutron/neutron.conf', u'source': [u'config/neutron/templates/neutron.conf.j2', u'config/neutron/templates/neutron.linuxbridge.conf.j2'], u'perm': u'0600', u'owner': u'neutron'}
DEBUG:/usr/local/bin/kolla_mesos_start:Name is: ml2_conf.ini.j2, Item is: {u'dest': u'/etc/neutron/plugins/ml2/ml2_conf.ini', u'source': [u'config/neutron/templates/ml2_conf.ini.j2', u'config/neutron/templates/ml2_conf.linuxbridge.ini.j2'], u'perm': u'0600', u'owner': u'neutron'}
INFO:/usr/local/bin/kolla_mesos_start:** > Running daemon
DEBUG:/usr/local/bin/kolla_mesos_start:Running command: neutron-linuxbridge-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/ml2_conf.ini
/bin/sh: 1: neutron-linuxbridge-agent: not found
DEBUG:/usr/local/bin/kolla_mesos_start:Daemon poll ret='127'