yii\web\Request::cookieValidationKey is now automatically generated by the installation script for the basic and advanced application templates

composer.json

@@ -1,49 +1,53 @@
 {
-	"name": "yiisoft/yii2-app-basic",
-	"description": "Yii 2 Basic Application Template",
-	"keywords": ["yii2", "framework", "basic", "application template"],
-	"homepage": "http://www.yiiframework.com/",
-	"type": "project",
-	"license": "BSD-3-Clause",
-	"support": {
-		"issues": "https://github.com/yiisoft/yii2/issues?state=open",
-		"forum": "http://www.yiiframework.com/forum/",
-		"wiki": "http://www.yiiframework.com/wiki/",
-		"irc": "irc://irc.freenode.net/yii",
-		"source": "https://github.com/yiisoft/yii2"
-	},
-	"minimum-stability": "dev",
-	"require": {
-		"php": ">=5.4.0",
-		"yiisoft/yii2": "*",
-		"yiisoft/yii2-bootstrap": "*",
-		"yiisoft/yii2-swiftmailer": "*"
-	},
-	"require-dev": {
-		"yiisoft/yii2-codeception": "*",
-		"yiisoft/yii2-debug": "*",
-		"yiisoft/yii2-gii": "*"
-	},
-	"suggest": {
-		"codeception/codeception": "Codeception, 2.0.* is currently works well with Yii.",
-		"codeception/specify": "BDD style code blocks for PHPUnit and Codeception",
-		"codeception/verify": "BDD Assertions for PHPUnit and Codeception"
-	},
-	"scripts": {
-		"post-create-project-cmd": [
-			"yii\\composer\\Installer::setPermission"
-		]
-	},
-	"config": {
-		"process-timeout": 1800
-	},
-	"extra": {
-		"writable": [
-			"runtime",
-			"web/assets"
-		],
-		"executable": [
-			"yii"
-		]
-	}
+    "name": "yiisoft/yii2-app-basic",
+    "description": "Yii 2 Basic Application Template",
+    "keywords": ["yii2", "framework", "basic", "application template"],
+    "homepage": "http://www.yiiframework.com/",
+    "type": "project",
+    "license": "BSD-3-Clause",
+    "support": {
+        "issues": "https://github.com/yiisoft/yii2/issues?state=open",
+        "forum": "http://www.yiiframework.com/forum/",
+        "wiki": "http://www.yiiframework.com/wiki/",
+        "irc": "irc://irc.freenode.net/yii",
+        "source": "https://github.com/yiisoft/yii2"
+    },
+    "minimum-stability": "dev",
+    "require": {
+        "php": ">=5.4.0",
+        "yiisoft/yii2": "*",
+        "yiisoft/yii2-bootstrap": "*",
+        "yiisoft/yii2-swiftmailer": "*"
+    },
+    "require-dev": {
+        "yiisoft/yii2-codeception": "*",
+        "yiisoft/yii2-debug": "*",
+        "yiisoft/yii2-gii": "*"
+    },
+    "suggest": {
+        "codeception/codeception": "Codeception, 2.0.* is currently works well with Yii.",
+        "codeception/specify": "BDD style code blocks for PHPUnit and Codeception",
+        "codeception/verify": "BDD Assertions for PHPUnit and Codeception"
+    },
+    "scripts": {
+        "post-create-project-cmd": [
+            "yii\\composer\\Installer::setPermission",
+            "yii\\composer\\Installer::generateCookieValidationKey"
+        ]
+    },
+    "config": {
+        "process-timeout": 1800
+    },
+    "extra": {
+        "writable": [
+            "runtime",
+            "web/assets"
+        ],
+        "executable": [
+            "yii"
+        ],
+        "config": [
+            "config/web.php"
+        ]
+    }
 }

config/web.php

@@ -7,6 +7,10 @@ $config = [
     'basePath' => dirname(__DIR__),
     'bootstrap' => ['log'],
     'components' => [
+        'request' => [
+            // a secret key used to validate cookies. You may modify this key with your own one.
+            'cookieValidationKey' => '',
+        ],
         'cache' => [
             'class' => 'yii\caching\FileCache',
         ],