minor #19974 Make redis host configurable in tests (jakzal)

This PR was squashed before being merged into the 3.1 branch (closes #19974).

Discussion
----------

Make redis host configurable in tests

| Q             | A
| ------------- | ---
| Branch?       | 3.1
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Makes running tests on dockerized environments possible, since we can now export the `REDIS_HOST` environment variable:

```
REDIS_HOST=redis ./phpunit src/Symfony/Component/Cache
```

If this gets merged, in master we can later replace the `SYMFONY__REDIS_HOST` usage in the FrameworkBundle with the new `env(REDIS_HOST)`.

Commits
-------

c87de00 Make redis host configurable in tests

Author: fabpot

Tests/Functional/CachePoolsTest.php

@@ -17,6 +17,16 @@
 
 class CachePoolsTest extends WebTestCase
 {
+    protected function setUp()
+    {
+        $_SERVER['SYMFONY__REDIS_HOST'] = getenv('REDIS_HOST');
+    }
+
+    protected function tearDown()
+    {
+        unset($_SERVER['SYMFONY__REDIS_HOST']);
+    }
+
     public function testCachePools()
     {
         $this->doTestCachePools(array(), FilesystemAdapter::class);
@@ -30,7 +40,7 @@ public function testRedisCachePools()
         try {
             $this->doTestCachePools(array('root_config' => 'redis_config.yml', 'environment' => 'redis_cache'), RedisAdapter::class);
         } catch (\PHPUnit_Framework_Error_Warning $e) {
-            if (0 !== strpos($e->getMessage(), 'unable to connect to 127.0.0.1')) {
+            if (0 !== strpos($e->getMessage(), 'unable to connect to')) {
                 throw $e;
             }
             $this->markTestSkipped($e->getMessage());
@@ -50,7 +60,7 @@ public function testRedisCustomCachePools()
         try {
             $this->doTestCachePools(array('root_config' => 'redis_custom_config.yml', 'environment' => 'custom_redis_cache'), RedisAdapter::class);
         } catch (\PHPUnit_Framework_Error_Warning $e) {
-            if (0 !== strpos($e->getMessage(), 'unable to connect to 127.0.0.1')) {
+            if (0 !== strpos($e->getMessage(), 'unable to connect to')) {
                 throw $e;
             }
             $this->markTestSkipped($e->getMessage());

Tests/Functional/app/CachePools/redis_config.yml

@@ -4,6 +4,7 @@ imports:
 framework:
     cache:
         app: cache.adapter.redis
+        default_redis_provider: "redis://%redis_host%"
         pools:
             cache.pool1:
                 public: true

Tests/Functional/app/CachePools/redis_custom_config.yml

@@ -6,7 +6,7 @@ services:
         public: false
         class: Redis
         calls:
-            - [connect, [127.0.0.1]]
+            - [connect, ['%redis_host%']]
 
     cache.app:
         parent: cache.adapter.redis

phpunit.xml.dist

@@ -8,6 +8,7 @@
 >
     <php>
         <ini name="error_reporting" value="-1" />
+        <env name="REDIS_HOST" value="localhost" />
     </php>
 
     <testsuites>