From 8a0afc31b199c0fc7e25d5d7f4542bba954d34f7 Mon Sep 17 00:00:00 2001
From: Timo Tijhof <krinkle@fastmail.com>
Date: Sun, 6 Mar 2022 01:21:19 +0000
Subject: [PATCH] EtcdConfig: Remove YAML from available 'encoding' options

This appears impossible to use because the request is always made
with `Content-Type: application/json`.

* It seems unreasonable for an Etcd server to not support JSON.
* It seems unreasonable for an Etcd server to respond with YAML
  to a JSON request.
* It seems unlikely that anyone would prefer YAML over JSON for
  the automated encoding and decoding of fully automated inter-service
  communication.

Change-Id: I290e03e17d547c3dc675820bb024c940e02e097a
---
 RELEASE-NOTES-1.38             |  2 ++
 composer.json                  |  1 -
 includes/config/EtcdConfig.php | 15 ++++-----------
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/RELEASE-NOTES-1.38 b/RELEASE-NOTES-1.38
index 83c29ee6949..5ac33075557 100644
--- a/RELEASE-NOTES-1.38
+++ b/RELEASE-NOTES-1.38
@@ -266,6 +266,8 @@ because of Phabricator reports.
     User::removeWatch()
 * ParserOptions::setTidy() that had no effect and was deprecated since 1.35
   has been removed.
+* The "YAML" encoding option of EtcdConfig, has been removed without
+  deprecation.
 * The constant ApiBase::PARAM_VALUE_LINKS, deprecated since 1.35 has been
   removed.
 * UserLoadOptions, UserSaveOptions and UserResetAllOptions hooks, deprecated
diff --git a/composer.json b/composer.json
index fbc1f4e7037..c2cda6ddd63 100644
--- a/composer.json
+++ b/composer.json
@@ -116,7 +116,6 @@
 		"ext-readline": "Enable CLI history and autocomplete, e.g. for eval.php and other REPLs.",
 		"ext-sockets": "Enable CLI concurrent processing, e.g. for rebuildLocalisationCache.php.",
 		"ext-wikidiff2": "Faster text difference engine.",
-		"ext-yaml": "Enable YAML type for EtcdConfig backend.",
 		"ext-zlib": "Enable use of GZIP compression, e.g. for SqlBagOStuff (ParserCache), $wgCompressRevisions, or $wgUseFileCache.",
 		"monolog/monolog": "Enable use of MonologSpi ($wgMWLoggerDefaultSpi).",
 		"nmred/kafka-php": "Enable use of KafkaHandler (MonologSpi), or EventRelayerKafka ($wgEventRelayerConfig)."
diff --git a/includes/config/EtcdConfig.php b/includes/config/EtcdConfig.php
index fdc22954d57..c57e66acd40 100644
--- a/includes/config/EtcdConfig.php
+++ b/includes/config/EtcdConfig.php
@@ -51,8 +51,6 @@ class EtcdConfig implements Config, LoggerAwareInterface {
 	private $protocol;
 	/** @var string */
 	private $directory;
-	/** @var string */
-	private $encoding;
 	/** @var int */
 	private $baseCacheTTL;
 	/** @var int */
@@ -67,7 +65,6 @@ class EtcdConfig implements Config, LoggerAwareInterface {
 	 *   - service: service name used in SRV discovery. Defaults to 'etcd'. [optional]
 	 *   - port: custom host port [optional]
 	 *   - protocol: one of ("http", "https"). Defaults to http. [optional]
-	 *   - encoding: one of ("JSON", "YAML"). Defaults to JSON. [optional]
 	 *   - cache: BagOStuff instance or ObjectFactory spec thereof for a server cache.
 	 *            The cache will also be used as a fallback if etcd is down. [optional]
 	 *   - cacheTTL: logical cache TTL in seconds [optional]
@@ -79,7 +76,6 @@ class EtcdConfig implements Config, LoggerAwareInterface {
 			'service' => 'etcd',
 			'port' => null,
 			'protocol' => 'http',
-			'encoding' => 'JSON',
 			'cacheTTL' => 10,
 			'skewTTL' => 1,
 			'timeout' => 2
@@ -90,7 +86,6 @@ class EtcdConfig implements Config, LoggerAwareInterface {
 		$this->port = $params['port'];
 		$this->protocol = $params['protocol'];
 		$this->directory = trim( $params['directory'], '/' );
-		$this->encoding = $params['encoding'];
 		$this->skewCacheTTL = $params['skewTTL'];
 		$this->baseCacheTTL = max( $params['cacheTTL'] - $this->skewCacheTTL, 0 );
 		$this->timeout = $params['timeout'];
@@ -274,7 +269,9 @@ class EtcdConfig implements Config, LoggerAwareInterface {
 		list( $rcode, $rdesc, /* $rhdrs */, $rbody, $rerr ) = $this->http->run( [
 			'method' => 'GET',
 			'url' => "{$this->protocol}://{$host}/v2/keys/{$this->directory}/?recursive=true",
-			'headers' => [ 'content-type' => 'application/json' ]
+			'headers' => [
+				'content-type' => 'application/json',
+			]
 		] );
 
 		$response = [ 'config' => null, 'error' => null, 'retry' => false, 'modifiedIndex' => 0 ];
@@ -359,10 +356,6 @@ class EtcdConfig implements Config, LoggerAwareInterface {
 	 * @return mixed
 	 */
 	private function unserialize( $string ) {
-		if ( $this->encoding === 'YAML' ) {
-			return yaml_parse( $string );
-		} else {
-			return json_decode( $string, true );
-		}
+		return json_decode( $string, true );
 	}
 }