New trust management module

There is a new trust management module placed in the plugins folder:
plugins/modules/trust.py
The trust module allows to ensure presence and absence of trusts.

Here is the documentation for the module:
README-trust.md

New example playbooks have been added:
playbooks/trust/add-trust.yml
playbooks/trust/del-trust.yml
New tests added for the module:
tests/hbacrule/test_trust.yml

README-trust.md

@@ -0,0 +1,119 @@
+Trust module
+============
+
+Description
+-----------
+
+The trust module allows to ensure presence and absence of a domain trust.
+
+Features
+--------
+
+* Trust management
+
+Supported FreeIPA Versions
+--------------------------
+
+FreeIPA versions 4.4.0 and up are supported by the ipatrust module.
+
+Requirements
+------------
+
+**Controller**
+
+* Ansible version: 2.8+
+
+**Node**
+
+* Supported FreeIPA version (see above)
+* samba-4
+* ipa-server-trust-ad
+
+Usage
+=====
+
+Example inventory file
+
+```ini
+[ipaserver]
+ipaserver.test.local
+```
+
+Example playbook to ensure a one-way trust is present:
+Omitting the two_way option implies the default of one-way
+
+```yaml
+---
+- name: Playbook to ensure a one-way trust is present
+  hosts: ipaserver
+  become: true
+
+  tasks:
+  - name: ensure the one-way trust present
+    ipatrust:
+      realm: ad.example.test
+      admin: Administrator
+      password: secret_password
+      state: present
+```
+
+Example playbook to ensure a two-way trust is present using a shared-secret:
+
+```yaml
+---
+- name: Playbook to ensure a two-way trust is present
+  hosts: ipaserver
+  become: true
+
+  tasks:
+  - name: ensure the two-way trust is present
+    ipatrust:
+      realm: ad.example.test
+      trust_secret: my_share_Secret
+      two_way: True
+      state: present
+```
+
+Example playbook to ensure a trust is absent:
+
+```yaml
+---
+- name: Playbook to ensure a trust is absent
+  hosts: ipaserver
+  become: true
+
+  tasks:
+  - name: ensure the trust is absent
+    ipatrust:
+      realm: ad.example.test
+      state: absent
+```
+
+This will only delete the ipa-side of the trust and it does NOT delete the id-range that matches the trust,
+
+Variables
+=========
+
+ipatrust
+-------
+
+Variable | Description | Required
+-------- | ----------- | --------
+`ipaadmin_principal` | The admin principal is a string and defaults to `admin` | no
+`ipaadmin_password` | The admin password is a string and is required if there is no admin ticket available on the node | no
+`realm` | The realm name string. | yes
+`admin` | Active Directory domain administrator string. | no
+`password` | Active Directory domain administrator's password string. | no
+`server` | Domain controller for the Active Directory domain string. | no
+`trust_secret` | Shared secret for the trust string. | no
+`base_id` | First posix id for the trusted domain integer. | no
+`range_size` | Size of the ID range reserved for the trusted domain integer. | no
+`range_type` | Type of trusted domain ID range, It can be one of `ipa-ad-trust` or `ipa-ad-trust-posix`and defaults to `ipa-ad-trust`. | no
+`two_way` | Establish bi-directional trust. By default trust is inbound one-way only. (bool) | no
+`external` | Establish external trust to a domain in another forest. The trust is not transitive beyond the domain. (bool) | no
+`state` | The state to ensure. It can be one of `present` or `absent`, default: `present`. | yes
+
+Authors
+=======
+
+Rob Verduijn