Fix backend API certificate generation

Some dependencies for generating backend API certificates were missing
but were undetected because they were fulfilled by other vault playbooks
run earlier during the deployment process.

This was detected when playbook hosts were extended to include separate
network hosts running some OpenStack services.

Author: priteau

etc/kayobe/ansible/vault-generate-backend-tls.yml

@@ -1,10 +1,42 @@
 ---
+# Required for uri module to work with self-signed certificates and for systems to trust
+# the self-signed CA
+- name: Install CA on network hosts
+  hosts: controllers
+  tasks:
+    - name: Copy the intermediate CA
+      copy:
+        src: "{{ kayobe_env_config_path }}/vault/OS-TLS-ROOT.pem"
+        dest: "{{ '/etc/pki/ca-trust/source/anchors/OS-TLS-ROOT.crt' if ansible_facts.os_family == 'RedHat' else '/usr/local/share/ca-certificates/OS-TLS-ROOT.crt' }}"
+        mode: 0644
+      become: true
+
+    - name: update system CA
+      become: true
+      shell: "{{ 'update-ca-trust' if ansible_facts.os_family == 'RedHat' else 'update-ca-certificates' }}"
+
 - name: Generate backend API certificates
   hosts: controllers
   vars:
     vault_api_addr: "https://{{ kolla_internal_fqdn }}:8200"
     vault_intermediate_ca_name: "OS-TLS-INT"
   tasks:
+    - name: Set a fact about the virtualenv on the remote system
+      set_fact:
+        virtualenv: "{{ ansible_python_interpreter | dirname | dirname }}"
+      when:
+        - ansible_python_interpreter is defined
+        - not ansible_python_interpreter.startswith('/bin/')
+        - not ansible_python_interpreter.startswith('/usr/bin/')
+
+    - name: Ensure Python hvac module is installed
+      pip:
+        name: hvac
+        state: latest
+        extra_args: "{% if pip_upper_constraints_file %}-c {{ pip_upper_constraints_file }}{% endif %}"
+        virtualenv: "{{ virtualenv is defined | ternary(virtualenv, omit) }}"
+      become: "{{ virtualenv is not defined }}"
+
     - name: Include Vault keys
       include_vars:
         file: "{{ kayobe_env_config_path }}/vault/overcloud-vault-keys.json"