There is not much to say. Reproducer is:

1. Clone tripleo-quickstart
2. Apply following patch, without it on CentOS7 quicktart fails with suntax error:
[root@dell-t5810ws-rdo-13 tripleo-quickstart]$ git show bfbc1d00e2fc82e44e3fdd92382b0ec2d8d13b4c
commit bfbc1d00e2fc82e44e3fdd92382b0ec2d8d13b4c
Author: root <email address hidden>
Date:   Mon Oct 7 16:35:11 2019 +0200

    para fix

diff --git a/requirements.txt b/requirements.txt
index 2740482..9206b46 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 cmd2==0.8.5
 ara<1.0
-ansible>=2.8,<2.9
+ansible>=2.7,<2.8
 jmespath
 netaddr>=0.7.18
 os-client-config
[root@dell-t5810ws-rdo-13 tripleo-quickstart]$ 
3. deploy undercloud with:
[root@dell-t5810ws-rdo-13 tripleo-quickstart]$ ./quickstart.sh --clean --teardown all --no-clone --release master-tripleo-ci --nodes /root/tripleo/tripleo-quickstart/para-standard-nodes.yaml  dell-t5810ws-rdo-13.tpb.lab.eng.brq.redhat.com
3a. nodes setting:
[root@dell-t5810ws-rdo-13 tripleo-quickstart]$ cat para-standard-nodes.yaml
# Tell tripleo which nodes to deploy.
topology_map:
  Controller:
    scale: 3
  Compute:
    scale: 1

repo_setup_run_update: false
control_memory: 6144
compute_memory: 6144

# undercloud resources
undercloud_disk: 150
#undercloud_memory: 16384
undercloud_memory: 8192
undercloud_vcpu: 4

# opstools resources
opstools_memory: 4096

flavors:
  compute:
    memory: '{{compute_memory|default(default_memory)}}'
    disk: '{{compute_disk|default(default_disk)}}'
    vcpu: '{{compute_vcpu|default(default_vcpu)}}'

  control:
    memory: '{{control_memory|default(default_memory)}}'
    disk: '{{control_disk|default(default_disk)}}'
    vcpu: '{{control_vcpu|default(default_vcpu)}}'

  ceph:
    memory: '{{ceph_memory|default(default_memory)}}'
    disk: '{{ceph_disk|default(default_disk)}}'
    vcpu: '{{ceph_vcpu|default(default_vcpu)}}'
    extradisks: true

  blockstorage:
    memory: '{{block_memory|default(default_memory)}}'
    disk: '{{block_disk|default(default_disk)}}'
    vcpu: '{{block_vcpu|default(default_vcpu)}}'

  objectstorage:
    memory: '{{objectstorage_memory|default(default_memory)}}'
    disk: '{{objectstorage_disk|default(default_disk)}}'
    vcpu: '{{objectstorage_vcpu|default(default_vcpu)}}'
    extradisks: true

  opstools:
    memory: '{{osptools_memory|default(default_memory)}}'
    disk: '{{osptools_disk|default(default_disk)}}'
    vcpu: '{{osptools_vcpu|default(default_vcpu)}}'

  undercloud:
    memory: '{{undercloud_memory|default(default_memory)}}'
    disk: '{{undercloud_disk|default(default_disk)}}'
    vcpu: '{{undercloud_vcpu|default(default_vcpu)}}'

node_count: 7
overcloud_nodes:
  - name: control_0
    flavor: control
    virtualbmc_port: 6230

  - name: control_1
    flavor: control
    virtualbmc_port: 6231

  - name: control_2
    flavor: control
    virtualbmc_port: 6232

  - name: compute_0
    flavor: compute
    virtualbmc_port: 6233

#  - name: opstools_0
#    flavor: control
#    virtualbmc_port: 6234

  - name: ceph_0
    flavor: ceph
    virtualbmc_port: 6235
  
  - name: ceph_1
    flavor: ceph
    virtualbmc_port: 6236
  
  - name: ceph_2
    flavor: ceph
    virtualbmc_port: 6237
[root@dell-t5810ws-rdo-13 tripleo-quickstart]$ 
4. After successful undercloud deploy, deploy overcloud:
[stack@undercloud ~]$ ./overcloud-deploy.sh

That's it. This workflow used to work for me, but is not any more.