Add option to blockinfile to wrap inserted block with blank lines (#81083)

* Add new blockinfile options 'prepend_newline' and 'append_newline' to wrap inserted block with blank lines

changelogs/fragments/81083-add-blockinfile-append-and-prepend-new-line-options.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - blockinfile - add append_newline and prepend_newline options (https://github.com/ansible/ansible/issues/80835).

lib/ansible/modules/blockinfile.py

@@ -90,6 +90,22 @@ options:
     type: str
     default: END
     version_added: '2.5'
+  append_newline:
+    required: false
+    description:
+    - Append a blank line to the inserted block, if this does not appear at the end of the file.
+    - Note that this attribute is not considered when C(state) is set to C(absent)
+    type: bool
+    default: no
+    version_added: '2.16'
+  prepend_newline:
+    required: false
+    description:
+    - Prepend a blank line to the inserted block, if this does not appear at the beginning of the file.
+    - Note that this attribute is not considered when C(state) is set to C(absent)
+    type: bool
+    default: no
+    version_added: '2.16'
 notes:
   - When using 'with_*' loops be aware that if you do not set a unique mark the block will be overwritten on each iteration.
   - As of Ansible 2.3, the O(dest) option has been changed to O(path) as default, but O(dest) still works as well.
@@ -117,9 +133,11 @@ attributes:
 
 EXAMPLES = r'''
 # Before Ansible 2.3, option 'dest' or 'name' was used instead of 'path'
-- name: Insert/Update "Match User" configuration block in /etc/ssh/sshd_config
+- name: Insert/Update "Match User" configuration block in /etc/ssh/sshd_config prepending and appending a new line
   ansible.builtin.blockinfile:
     path: /etc/ssh/sshd_config
+    append_newline: true
+    prepend_newline: true
     block: |
       Match User ansible-agent
       PasswordAuthentication no
@@ -231,6 +249,8 @@ def main():
             validate=dict(type='str'),
             marker_begin=dict(type='str', default='BEGIN'),
             marker_end=dict(type='str', default='END'),
+            append_newline=dict(type='bool', default=False),
+            prepend_newline=dict(type='bool', default=False),
         ),
         mutually_exclusive=[['insertbefore', 'insertafter']],
         add_file_common_args=True,
@@ -274,6 +294,7 @@ def main():
     block = to_bytes(params['block'])
     marker = to_bytes(params['marker'])
     present = params['state'] == 'present'
+    blank_line = [b(os.linesep)]
 
     if not present and not path_exists:
         module.exit_json(changed=False, msg="File %s not present" % path)
@@ -337,7 +358,26 @@ def main():
         if not lines[n0 - 1].endswith(b(os.linesep)):
             lines[n0 - 1] += b(os.linesep)
 
+    # Before the block: check if we need to prepend a blank line
+    # If yes, we need to add the blank line if we are at the beginning of the file
+    # or if the previous line is not a blank line
+    # In both cases, we need to shift by one on the right the inserting position of the block
+    if params['prepend_newline'] and present:
+        if n0 != 0 and lines[n0 - 1] != b(os.linesep):
+            lines[n0:n0] = blank_line
+            n0 += 1
+
+    # Insert the block
     lines[n0:n0] = blocklines
+
+    # After the block: check if we need to append a blank line
+    # If yes, we need to add the blank line if we are at the end of the file
+    # or if the line right after is not a blank line
+    if params['append_newline'] and present:
+        line_after_block = n0 + len(blocklines)
+        if line_after_block < len(lines) and lines[line_after_block] != b(os.linesep):
+            lines[line_after_block:line_after_block] = blank_line
+
     if lines:
         result = b''.join(lines)
     else:

test/integration/targets/blockinfile/tasks/append_newline.yml

@@ -0,0 +1,119 @@
+- name: Create append_newline test file
+  copy:
+    dest: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    content: |
+      line1
+      line2
+      line3
+
+- name: add content to file appending a new line
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    append_newline: true
+    insertafter: "line1"
+    block: |
+      line1.5
+  register: insert_appending_a_new_line
+
+- name: add content to file appending a new line (again)
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    append_newline: true
+    insertafter: "line1"
+    block: |
+      line1.5
+  register: insert_appending_a_new_line_again
+
+- name: get file content after adding content appending a new line
+  stat:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+  register: appended_a_new_line
+
+- name: check content is the expected one after inserting content appending a new line
+  assert:
+    that:
+      - insert_appending_a_new_line is changed
+      - insert_appending_a_new_line_again is not changed
+      - appended_a_new_line.stat.checksum == "525ffd613a0b0eb6675e506226dc2adedf621f34"
+
+- name: add content to file without appending a new line
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    marker: "#{mark} UNWRAPPED TEXT"
+    insertafter: "line2"
+    block: |
+      line2.5
+  register: insert_without_appending_new_line
+
+- name: get file content after adding content without appending a new line
+  stat:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+  register: without_appending_new_line
+
+- name: check content is the expected one after inserting without appending a new line
+  assert:
+    that:
+      - insert_without_appending_new_line is changed
+      - without_appending_new_line.stat.checksum == "d5f5ed1428af50b5484a5184dc7e1afda1736646"
+
+- name: append a new line to existing block
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    append_newline: true
+    marker: "#{mark} UNWRAPPED TEXT"
+    insertafter: "line2"
+    block: |
+      line2.5
+  register: append_new_line_to_existing_block
+
+- name: get file content after appending a line to existing block
+  stat:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+  register: new_line_appended
+
+- name: check content is the expected one after appending a new line to an existing block
+  assert:
+    that:
+      - append_new_line_to_existing_block is changed
+      - new_line_appended.stat.checksum == "b09dd16be73a0077027d5a324294db8a75a7b0f9"
+
+- name: add a block appending a new line at the end of the file
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    append_newline: true
+    marker: "#{mark} END OF FILE TEXT"
+    insertafter: "line3"
+    block: |
+      line3.5
+  register: insert_appending_new_line_at_the_end_of_file
+
+- name: get file content after appending new line at the end of the file
+  stat:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+  register: inserted_block_appending_new_line_at_the_end_of_the_file
+
+- name: check content is the expected one after adding a block appending a new line at the end of the file
+  assert:
+    that:
+      - insert_appending_new_line_at_the_end_of_file is changed
+      - inserted_block_appending_new_line_at_the_end_of_the_file.stat.checksum == "9b90722b84d9bdda1be781cc4bd44d8979887691"
+
+
+- name: Removing a block with append_newline set to true does not append another line
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+    append_newline: true
+    marker: "#{mark} UNWRAPPED TEXT"
+    state: absent
+  register: remove_block_appending_new_line
+
+- name: get file content after removing existing block appending new line
+  stat:
+    path: "{{ remote_tmp_dir_test }}/append_newline.txt"
+  register: removed_block_appending_new_line
+
+- name: check content is the expected one after removing a block appending a new line
+  assert:
+    that:
+      - remove_block_appending_new_line is changed
+      - removed_block_appending_new_line.stat.checksum == "9a40d4c0969255cd6147537b38309d69a9b10049"

test/integration/targets/blockinfile/tasks/main.yml

@@ -39,3 +39,5 @@
 - import_tasks: insertafter.yml
 - import_tasks: insertbefore.yml
 - import_tasks: multiline_search.yml
+- import_tasks: append_newline.yml
+- import_tasks: prepend_newline.yml

test/integration/targets/blockinfile/tasks/prepend_newline.yml

@@ -0,0 +1,119 @@
+- name: Create prepend_newline test file
+  copy:
+    dest: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    content: |
+      line1
+      line2
+      line3
+
+- name: add content to file prepending a new line at the beginning of the file
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    prepend_newline: true
+    insertbefore: "line1"
+    block: |
+      line0.5
+  register: insert_prepending_a_new_line_at_the_beginning_of_the_file
+
+- name: get file content after adding content prepending a new line at the beginning of the file
+  stat:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+  register: prepended_a_new_line_at_the_beginning_of_the_file
+
+- name: check content is the expected one after prepending a new line at the beginning of the file
+  assert:
+    that:
+      - insert_prepending_a_new_line_at_the_beginning_of_the_file is changed
+      - prepended_a_new_line_at_the_beginning_of_the_file.stat.checksum == "bfd32c880bbfadd1983c67836c46bf8ed9d50343"
+
+- name: add content to file prepending a new line
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    prepend_newline: true
+    marker: "#{mark} WRAPPED TEXT"
+    insertafter: "line1"
+    block: |
+      line1.5
+  register: insert_prepending_a_new_line
+
+- name: add content to file prepending a new line (again)
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    prepend_newline: true
+    marker: "#{mark} WRAPPED TEXT"
+    insertafter: "line1"
+    block: |
+      line1.5
+  register: insert_prepending_a_new_line_again
+
+- name: get file content after adding content prepending a new line
+  stat:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+  register: prepended_a_new_line
+
+- name: check content is the expected one after inserting content prepending a new line
+  assert:
+    that:
+      - insert_prepending_a_new_line is changed
+      - insert_prepending_a_new_line_again is not changed
+      - prepended_a_new_line.stat.checksum == "d5b8b42690f4a38b9a040adc3240a6f81ad5f8ee"
+
+- name: add content to file without prepending a new line
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    marker: "#{mark} UNWRAPPED TEXT"
+    insertafter: "line3"
+    block: |
+      line3.5
+  register: insert_without_prepending_new_line
+
+- name: get file content after adding content without prepending a new line
+  stat:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+  register: without_prepending_new_line
+
+- name: check content is the expected one after inserting without prepending a new line
+  assert:
+    that:
+      - insert_without_prepending_new_line is changed
+      - without_prepending_new_line.stat.checksum == "ad06200e7ee5b22b7eff4c57075b42d038eaffb6"
+
+- name: prepend a new line to existing block
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    prepend_newline: true
+    marker: "#{mark} UNWRAPPED TEXT"
+    insertafter: "line3"
+    block: |
+      line3.5
+  register: prepend_new_line_to_existing_block
+
+- name: get file content after prepending a new line to an existing block
+  stat:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+  register: new_line_prepended
+
+- name: check content is the expected one after prepending a new line to an existing block
+  assert:
+    that:
+      - prepend_new_line_to_existing_block is changed
+      - new_line_prepended.stat.checksum == "f2dd48160fb3c7c8e02d292666a1a3f08503f6bf"
+
+- name: Removing a block with prepend_newline set to true does not prepend another line
+  blockinfile:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+    prepend_newline: true
+    marker: "#{mark} UNWRAPPED TEXT"
+    state: absent
+  register: remove_block_prepending_new_line
+
+- name: get file content after removing existing block prepending new line
+  stat:
+    path: "{{ remote_tmp_dir_test }}/prepend_newline.txt"
+  register: removed_block_prepending_new_line
+
+- name: check content is the expected one after removing a block prepending a new line
+  assert:
+    that:
+      - remove_block_prepending_new_line is changed
+      - removed_block_prepending_new_line.stat.checksum == "c97c3da7d607acfd5d786fbb81f3d93d867c914a"