Add a requirements.txt to the ansible container and have pip install …

ansible-playbook/Dockerfile

@@ -1,5 +1,8 @@
 FROM python:3.7
 
+ADD requirements.txt /tmp/requirements.txt
+RUN pip install -r /tmp/requirements.txt
+
 RUN pip install 'ansible~=$ANSIBLE_VERSION'
 
 ENV VAULT_PASSWORD=

ansible-playbook/requirements.txt

@@ -0,0 +1,7 @@
+# The openstack SDK is an enabler for all the OpenStack modules at
+# https://docs.ansible.com/ansible/latest/modules/list_of_cloud_modules.html#openstack
+openstacksdk
+
+# The netaddr module is neded to use the ipaddr jinja filter as used in the docker swarm
+# playbook when creating custom networks
+netaddr