luks_device - make add/removal of keyfile/passphrase idempotent (#168)

* Update documentation, adjust tests, add changelog fragment.

* Move module unit test to correct place.

* Implement keyfile / passphrase test.

tests/integration/targets/luks_device/tasks/tests/key-management.yml

@@ -44,6 +44,21 @@
     keyfile: "{{ role_path }}/files/keyfile1"
     new_keyfile: "{{ role_path }}/files/keyfile2"
   become: yes
+  register: result_1
+
+- name: Give access to keyfile2 (idempotent)
+  luks_device:
+    device: "{{ cryptfile_device }}"
+    state: closed
+    keyfile: "{{ role_path }}/files/keyfile1"
+    new_keyfile: "{{ role_path }}/files/keyfile2"
+  become: yes
+  register: result_2
+
+- assert:
+    that:
+      - result_1 is changed
+      - result_2 is not changed
 
 # Access: keyfile1 and keyfile2
 
@@ -75,6 +90,21 @@
     keyfile: "{{ role_path }}/files/keyfile1"
     remove_keyfile: "{{ role_path }}/files/keyfile1"
   become: yes
+  register: result_1
+
+- name: Remove access from keyfile1 (idempotent)
+  luks_device:
+    device: "{{ cryptfile_device }}"
+    state: closed
+    keyfile: "{{ role_path }}/files/keyfile1"
+    remove_keyfile: "{{ role_path }}/files/keyfile1"
+  become: yes
+  register: result_2
+
+- assert:
+    that:
+      - result_1 is changed
+      - result_2 is not changed
 
 # Access: keyfile2
 

tests/integration/targets/luks_device/tasks/tests/passphrase.yml

@@ -56,6 +56,21 @@
     passphrase: "{{ cryptfile_passphrase1 }}"
     new_passphrase: "{{ cryptfile_passphrase2 }}"
   become: yes
+  register: result_1
+
+- name: Give access to passphrase2 (idempotent)
+  luks_device:
+    device: "{{ cryptfile_device }}"
+    state: closed
+    passphrase: "{{ cryptfile_passphrase1 }}"
+    new_passphrase: "{{ cryptfile_passphrase2 }}"
+  become: yes
+  register: result_2
+
+- assert:
+    that:
+      - result_1 is changed
+      - result_2 is not changed
 
 - name: Open with passphrase2
   luks_device:
@@ -130,6 +145,20 @@
     state: closed
     remove_passphrase: "{{ cryptfile_passphrase1 }}"
   become: yes
+  register: result_1
+
+- name: Remove access for passphrase1 (idempotent)
+  luks_device:
+    device: "{{ cryptfile_device }}"
+    state: closed
+    remove_passphrase: "{{ cryptfile_passphrase1 }}"
+  become: yes
+  register: result_2
+
+- assert:
+    that:
+      - result_1 is changed
+      - result_2 is not changed
 
 - name: Try to open with passphrase1
   luks_device: