From fb55038d7516149aecd9a617572437b8c2c13f50 Mon Sep 17 00:00:00 2001
From: Sam Doran <sdoran@redhat.com>
Date: Fri, 29 Jun 2018 20:15:43 -0400
Subject: [PATCH] Add warning when using an empty regexp in lineinfile (#42013)
* Revert "Account for empty string regexp in lineinfile (#41451)"
This reverts commit 4b5b4a760c5217bdfd1d45efd224e2762e9898b0.
* Use context managers for interacting with files
* Store line and regexp parameters in a variable
* Add warning when regexp is an empty string
* Remove '=' from error messages
* Update warning message and add changelog
* Add tests
* Improve warning message
Offer an equivalent regexp that won't trigger the warning.
Update tests to match new warning.
* Add porting guide entry for lineinfile change
---
.../fragments/lineinfile-empty-regexp.yml | 2 ++
.../rst/porting_guides/porting_guide_2.7.rst | 5 ++++
lib/ansible/modules/files/lineinfile.py | 30 +++++++++++--------
.../targets/lineinfile/tasks/main.yml | 12 ++++++--
4 files changed, 34 insertions(+), 15 deletions(-)
create mode 100644 changelogs/fragments/lineinfile-empty-regexp.yml
diff --git a/changelogs/fragments/lineinfile-empty-regexp.yml b/changelogs/fragments/lineinfile-empty-regexp.yml
new file mode 100644
index 00000000000..8ea3a3a5f8e
--- /dev/null
+++ b/changelogs/fragments/lineinfile-empty-regexp.yml
@@ -0,0 +1,2 @@
+minor_changes:
+ - lineinfile - add warning when using an empty regexp (https://github.com/ansible/ansible/issues/29443)
diff --git a/docs/docsite/rst/porting_guides/porting_guide_2.7.rst b/docs/docsite/rst/porting_guides/porting_guide_2.7.rst
index de68321d943..cb7db78bb44 100644
--- a/docs/docsite/rst/porting_guides/porting_guide_2.7.rst
+++ b/docs/docsite/rst/porting_guides/porting_guide_2.7.rst
@@ -70,6 +70,11 @@ Major changes in popular modules are detailed here
:ref:`DEFAULT_SYSLOG_FACILITY`. If you have :ref:`DEFAULT_SYSLOG_FACILITY` configured, the
location of remote logs on systems which use journald may change.
+* The ``lineinfile`` module was changed to show a warning when using an empty string as a regexp.
+ Since an empty regexp matches every line in a file, it will replace the last line in a file rather
+ than inserting. If this is the desired behavior, use ``'^'`` which will match every line and
+ will not trigger the warning.
+
Modules removed
---------------
diff --git a/lib/ansible/modules/files/lineinfile.py b/lib/ansible/modules/files/lineinfile.py
index 3b8c14c1cb7..1da7c500fbb 100644
--- a/lib/ansible/modules/files/lineinfile.py
+++ b/lib/ansible/modules/files/lineinfile.py
@@ -252,7 +252,7 @@ def present(module, dest, regexp, line, insertafter, insertbefore, create,
if module._diff:
diff['before'] = to_native(b('').join(b_lines))
- if regexp:
+ if regexp is not None:
bre_m = re.compile(to_bytes(regexp, errors='surrogate_or_strict'))
if insertafter not in (None, 'BOF', 'EOF'):
@@ -268,7 +268,7 @@ def present(module, dest, regexp, line, insertafter, insertbefore, create,
m = None
b_line = to_bytes(line, errors='surrogate_or_strict')
for lineno, b_cur_line in enumerate(b_lines):
- if regexp:
+ if regexp is not None:
match_found = bre_m.search(b_cur_line)
else:
match_found = b_line == b_cur_line.rstrip(b('\r\n'))
@@ -410,14 +410,14 @@ def absent(module, dest, regexp, line, backup):
if module._diff:
diff['before'] = to_native(b('').join(b_lines))
- if regexp:
+ if regexp is not None:
bre_c = re.compile(to_bytes(regexp, errors='surrogate_or_strict'))
found = []
b_line = to_bytes(line, errors='surrogate_or_strict')
def matcher(b_cur_line):
- if regexp:
+ if regexp is not None:
match_found = bre_c.search(b_cur_line)
else:
match_found = b_line == b_cur_line.rstrip(b('\r\n'))
@@ -478,18 +478,24 @@ def main():
path = params['path']
firstmatch = params['firstmatch']
regexp = params['regexp']
- line = params.get('line', None)
+ line = params['line']
+
+ if regexp == '':
+ module.warn(
+ "The regular expression is an empty string, which will match every line in the file. "
+ "This may have unintended consequences, such as replacing the last line in the file rather than appending. "
+ "If this is desired, use '^' to match every line in the file and avoid this warning.")
b_path = to_bytes(path, errors='surrogate_or_strict')
if os.path.isdir(b_path):
module.fail_json(rc=256, msg='Path %s is a directory !' % path)
if params['state'] == 'present':
- if backrefs and not regexp:
- module.fail_json(msg='regexp= is required with backrefs=true')
+ if backrefs and regexp is None:
+ module.fail_json(msg='regexp is required with backrefs=true')
- if params.get('line', None) is None:
- module.fail_json(msg='line= is required with state=present')
+ if line is None:
+ module.fail_json(msg='line is required with state=present')
# Deal with the insertafter default value manually, to avoid errors
# because of the mutually_exclusive mechanism.
@@ -497,13 +503,11 @@ def main():
if ins_bef is None and ins_aft is None:
ins_aft = 'EOF'
- line = params['line']
-
present(module, path, regexp, line,
ins_aft, ins_bef, create, backup, backrefs, firstmatch)
else:
- if not regexp and line is None:
- module.fail_json(msg='one of line= or regexp= is required with state=absent')
+ if regexp is None and line is None:
+ module.fail_json(msg='one of line or regexp is required with state=absent')
absent(module, path, regexp, line, backup)
diff --git a/test/integration/targets/lineinfile/tasks/main.yml b/test/integration/targets/lineinfile/tasks/main.yml
index 4838040ca90..e9c76c4aef7 100644
--- a/test/integration/targets/lineinfile/tasks/main.yml
+++ b/test/integration/targets/lineinfile/tasks/main.yml
@@ -720,6 +720,8 @@
###################################################################
# Issue 29443
+# When using an empty regexp, replace the last line (since it matches every line)
+# but also provide a warning.
- name: Deploy the test file for lineinfile
copy:
@@ -746,8 +748,14 @@
path: "{{ output_dir }}/test.txt"
register: result
-- name: Assert that the file contents match what is expected
+- name: Assert that the file contents match what is expected and a warning was displayed
assert:
that:
- insert_empty_regexp is changed
- - result.stat.checksum == '3baeade8eb2ecf4b01d70d541e9b8258b67c7f9f'
\ No newline at end of file
+ - warning_message in insert_empty_regexp.warnings
+ - result.stat.checksum == '23555a98ceaa88756b4c7c7bba49d9f86eed868f'
+ vars:
+ warning_message: >-
+ The regular expression is an empty string, which will match every line in the file.
+ This may have unintended consequences, such as replacing the last line in the file rather than appending.
+ If this is desired, use '^' to match every line in the file and avoid this warning.