config: allow reading both the defaults file and the modified config

In the process, rename config.proto to config.defaults (because that is
what it is now).

Also use dict.get('key', default_value) when querying os.environ, rather
than an if block, as it is more pythonic/readable/concise, and reduces
the number of dict lookups.

This change allows aurweb configuration to be done via either:
- copying config.defaults to config and modifying values
- creating a new config only containing modified values, next to a
  config.defaults containing unmodified values

The motivation for this change is to enable ansible configuration in our
flagship deployment by storing only changed values, and deferring to
config.defaults otherwise.

A side benefit is, it is easier to see what has changed by inspecting
only the site configuration file.

If a config.defaults file does not exist next to $AUR_CONFIG or in
$AUR_CONFIG_DEFAULTS, it is ignored and *all* values are expected to
live in the modified config file.

Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Lukas Fleischer <lfleischer@archlinux.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/web/lib/confparser.inc.php b/web/lib/confparser.inc.php
index 499481df..29f17e83 100644
--- a/web/lib/confparser.inc.php
+++ b/web/lib/confparser.inc.php
@@ -8,11 +8,21 @@ function config_load() {
 		if (!$path) {
 			$path = "/etc/aurweb/config";
 		}
+		$defaults_path = getenv('AUR_CONFIG_DEFAULTS');
+		if (!$defaults_path) {
+			$defaults_path = path . ".defaults";
+		}
+		if (file_exists($defaults_path)) {
+			$default_config = parse_ini_file($defaults_path, true, INI_SCANNER_RAW);
+		} else {
+			$default_config = [];
+		}
 		if (file_exists($path)) {
-			$AUR_CONFIG = parse_ini_file($path, true, INI_SCANNER_RAW);
+			$config = parse_ini_file($path, true, INI_SCANNER_RAW);
 		} else {
 			die("aurweb config file not found");
 		}
+		$AUR_CONFIG = array_replace_recursive($default_config, $config)
 	}
 }