On September 22nd, 2015, 3 nachm. CEST, Stephen Gallagher wrote:

config/roles/databaseserver/role.py (Diff revision 2)
		51	def tweak_lines(lines_iterable, tweaking_rules, append_if_missing=False):
		52	for rule in tweaking_rules:
		53	regex = rule['regex']
		54	if isinstance(regex, str):
		55	rule['regex'] = re.compile(regex)
		56	rule.setdefault('global', True)
		57	rule.setdefault('append_if_missing', append_if_missing)
		58
		59	found_regexes = set()
		60	ignore_regexes = set()
		61
		62	for line in lines_iterable:
		63	lines_to_append = []
		64	for rule in tweaking_rules:
		65	regex = rule['regex']
		66	if regex not in ignore_regexes:
		67	m = regex.search(line)
		68	if m:
		69	found_regexes.add(regex)
		70	if not rule['global']:
		71	ignore_regexes.add(regex)
		72	if 'replace' in rule:
		73	line = regex.sub(rule['replace'], line)
		74	if 'append' in rule:
		75	lines_to_append.append(rule['append'])
		76	yield line
		77	for l in lines_to_append:
		78	yield l + "\n"
		79
		80	for rule in tweaking_rules:
		81	if (
		82	rule['append_if_missing'] and
		83	rule['regex'] not in found_regexes):
		84	if 'replace' in rule:
		85	yield rule['replace'] + "\n"
		86	if 'append' in rule:
		87	yield rule['append'] + "\n"
		88
		89

This function is very difficult to follow. Please add many comments.

On September 23rd, 2015, 4:03 nachm. CEST, Nils Philippsen wrote:

I don't like it very much myself ;), it's too unwieldy. It's basically a substitute for the functions of sed we used, you can match and replace or append, and optionally append at the end of the file if the regex never matched (for instance if future versions of the config file don't come with the matched directive so defaults get used). I thought about how to make this a bit more lean and easy to use so it's generally usable, but so far haven't come up with some concrete idea.

I don't like it very much myself ;), it's too unwieldy.

I've renamed it to _tweak_lines() so nobody gets the wrong idea that they should use this elsewhere ;).

- Nils

On September 23rd, 2015, 5:17 nachm. CEST, Nils Philippsen wrote:

Use an internal implementation instead of calling sed to tweak
configuration files. This has the neat side effect of overwriting the
target file as the last step, side-stepping the need to copy over the
backup file on errors.

This change requires python3-slip >= 0.6.4 because in previous versions
slip.util.files.overwrite_safely() doesn't preserve file ownership, and
the postgresql configuration files need to be owned by the postgres user.

https://github.com/libre-server/rolekit/issues/21

Deployed databaseserver role, compared contents of postgresql.conf, pg_hba.conf with what the original sed commands produced.