I am following steps for scaling as per https://docs.openstack.org/openstack-ansible/pike/admin/maintenance-tasks/scale-environment.html

the command openstack-ansible setup-everything.yml --limit @/root/add_host.limit --vvv fails as:

RUNNING HANDLER [haproxy_server : Regenerate haproxy configuration] *******************************************************************
Monday 26 February 2018  23:19:56 -0800 (0:00:01.208)       0:34:23.136 *******
container_name: "infra4"
physical_host: "infra4"
Using module file /opt/ansible-runtime/local/lib/python2.7/site-packages/ansible/modules/files/assemble.py
container_name: "infra4"
physical_host: "infra4"
<ip infra4> ESTABLISH SSH CONNECTION FOR USER: root
<ip infra4> SSH: EXEC ssh -C -o ControlMaster=auto -o ControlPersist=60s -o StrictHostKeyChecking=no -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o User=root -o ConnectTimeout=5 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o ServerAliveInterval=64 -o ServerAliveCountMax=1024 -o Compression=no -o TCPKeepAlive=yes -o VerifyHostKeyDNS=no -o ForwardX11=no -o ForwardAgent=yes -T -o ControlPath=/root/.ansible/cp/dbae8b1832 ip infra4 '/bin/sh -c '"'"'/usr/bin/python && sleep 0'"'"''
<ip infra4> (0, '\n{"src": "/etc/haproxy/conf.d", "changed": true, "group": "root", "uid": 0, "dest": "/etc/haproxy/haproxy.cfg", "checksum": "163187ca91948fe996b36c4cd0a24881fcfee88b", "md5sum": "64b19f839c96d83311a58832805e00dc", "invocation": {"module_args": {"ignore_hidden": false, "src": "/etc/haproxy/conf.d", "directory_mode": null, "force": null, "remote_src": false, "unsafe_writes": null, "selevel": null, "seuser": null, "setype": null, "group": null, "content": null, "dest": "/etc/haproxy/haproxy.cfg", "serole": null, "delimiter": null, "mode": null, "regexp": null, "owner": null, "follow": false, "validate": null, "attributes": null, "backup": false}}, "state": "file", "gid": 0, "mode": "0644", "owner": "root", "size": 27327, "msg": "OK"}\n', '')
NOTIFIED HANDLER Restart haproxy
changed: [infra4] => {
    "changed": true,
    "checksum": "163187ca91948fe996b36c4cd0a24881fcfee88b",
    "dest": "/etc/haproxy/haproxy.cfg",
    "gid": 0,
    "group": "root",
    "invocation": {
        "module_args": {
            "attributes": null,
            "backup": false,
            "content": null,
            "delimiter": null,
            "dest": "/etc/haproxy/haproxy.cfg",
            "directory_mode": null,
            "follow": false,
            "force": null,
            "group": null,
            "ignore_hidden": false,
            "mode": null,
            "owner": null,
            "regexp": null,
            "remote_src": false,
            "selevel": null,
            "serole": null,
            "setype": null,
            "seuser": null,
            "src": "/etc/haproxy/conf.d",
            "unsafe_writes": null,
            "validate": null
        }
    },
    "md5sum": "64b19f839c96d83311a58832805e00dc",
    "mode": "0644",
    "msg": "OK",
    "owner": "root",
    "size": 27327,
    "src": "/etc/haproxy/conf.d",
    "state": "file",
    "uid": 0
}

RUNNING HANDLER [haproxy_server : Restart haproxy] ************************************************************************************
Monday 26 February 2018  23:19:57 -0800 (0:00:01.325)       0:34:24.462 *******
container_name: "infra4"
physical_host: "infra4"
Using module file /opt/ansible-runtime/local/lib/python2.7/site-packages/ansible/modules/system/systemd.py
container_name: "infra4"
physical_host: "infra4"
<ip infra4> ESTABLISH SSH CONNECTION FOR USER: root
<ip infra4> SSH: EXEC ssh -C -o ControlMaster=auto -o ControlPersist=60s -o StrictHostKeyChecking=no -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o User=root -o ConnectTimeout=5 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o ServerAliveInterval=64 -o ServerAliveCountMax=1024 -o Compression=no -o TCPKeepAlive=yes -o VerifyHostKeyDNS=no -o ForwardX11=no -o ForwardAgent=yes -T -o ControlPath=/root/.ansible/cp/dbae8b1832 ip infra4 '/bin/sh -c '"'"'/usr/bin/python && sleep 0'"'"''
<ip infra4> (1, '\n{"msg": "Unable to restart service haproxy: Job for haproxy.service failed because the control process exited with error code. See \\"systemctl status haproxy.service\\" and \\"journalctl -xe\\" for details.\\n", "failed": true, "invocation": {"module_args": {"no_block": false, "name": "haproxy", "enabled": true, "daemon_reload": true, "state": "restarted", "user": false, "masked": null}}}\n', '')
fatal: [infra4]: FAILED! => {
    "changed": false,
    "failed": true,
    "invocation": {
        "module_args": {
            "daemon_reload": true,
            "enabled": true,
            "masked": null,
            "name": "haproxy",
            "no_block": false,
            "state": "restarted",
            "user": false
        }
    },
    "msg": "Unable to restart service haproxy: Job for haproxy.service failed because the control process exited with error code. See \"systemctl status haproxy.service\" and \"journalctl -xe\" for details.\n"
}