bug #53631 [DependencyInjection] Fix loading all env vars from secrets when only a subset is needed (nicolas-grekas)

nicolas-grekas · nicolas-grekas · commit 84f5bdc24399 · 2024-01-29T13:16:08.000+01:00
This PR was merged into the 6.4 branch. Discussion ---------- [DependencyInjection] Fix loading all env vars from secrets when only a subset is needed | Q | A | ------------- | --- | Branch? | 6.4 | Bug fix? | yes | New feature? | no | Deprecations? | no | Issues | Fix #53429 | License | MIT As spotted in the linked issue, we have a significant performance issue when loading env vars. The issue is that when one env var is needed but not defined, we still decrypt all existing env vars. This also means we have a scalability issue when the number of env vars increases. Since this happens usually on every single requests, this can burn the CPU. The solution implemented in this PR is to use lazy strings to load env vars so that we don't decrypt them unless they are actually needed. Commits ------- 1d6f795 [DependencyInjection] Fix loading all env vars from secrets when only a subset is needed
diff --git a/src/Symfony/Bundle/FrameworkBundle/Secrets/SodiumVault.php b/src/Symfony/Bundle/FrameworkBundle/Secrets/SodiumVault.php
@@ -12,6 +12,7 @@
 namespace Symfony\Bundle\FrameworkBundle\Secrets;
 
 use Symfony\Component\DependencyInjection\EnvVarLoaderInterface;
+use Symfony\Component\String\LazyString;
 use Symfony\Component\VarExporter\VarExporter;
 
 /**
@@ -169,7 +170,14 @@ public function list(bool $reveal = false): array
 
     public function loadEnvVars(): array
     {
-        return $this->list(true);
+        $envs = [];
+        $reveal = $this->reveal(...);
+
+        foreach ($this->list() as $name => $value) {
+            $envs[$name] = LazyString::fromCallable($reveal, $name);
+        }
+
+        return $envs;
     }
 
     private function loadKeys(): void
diff --git a/src/Symfony/Component/DependencyInjection/EnvVarLoaderInterface.php b/src/Symfony/Component/DependencyInjection/EnvVarLoaderInterface.php
@@ -19,7 +19,7 @@
 interface EnvVarLoaderInterface
 {
     /**
-     * @return string[] Key/value pairs that can be accessed using the regular "%env()%" syntax
+     * @return array<string|\Stringable> Key/value pairs that can be accessed using the regular "%env()%" syntax
      */
     public function loadEnvVars(): array;
 }
diff --git a/src/Symfony/Component/DependencyInjection/EnvVarProcessor.php b/src/Symfony/Component/DependencyInjection/EnvVarProcessor.php
@@ -164,10 +164,16 @@ public function getEnv(string $prefix, string $name, \Closure $getEnv): mixed
         if (false !== $i || 'string' !== $prefix) {
             $env = $getEnv($name);
         } elseif ('' === ($env = $_ENV[$name] ?? (str_starts_with($name, 'HTTP_') ? null : ($_SERVER[$name] ?? null)))
-            || (false !== $env && false === ($env = $env ?? getenv($name) ?? false)) // null is a possible value because of thread safety issues
+            || (false !== $env && false === $env ??= getenv($name) ?? false) // null is a possible value because of thread safety issues
         ) {
-            foreach ($this->loadedVars as $vars) {
-                if (false !== ($env = ($vars[$name] ?? $env)) && '' !== $env) {
+            foreach ($this->loadedVars as $i => $vars) {
+                if (false === $env = $vars[$name] ?? $env) {
+                    continue;
+                }
+                if ($env instanceof \Stringable) {
+                    $this->loadedVars[$i][$name] = $env = (string) $env;
+                }
+                if ('' !== ($env ?? '')) {
                     break;
                 }
             }
@@ -185,7 +191,13 @@ public function getEnv(string $prefix, string $name, \Closure $getEnv): mixed
                             continue;
                         }
                         $this->loadedVars[] = $vars = $loader->loadEnvVars();
-                        if (false !== ($env = ($vars[$name] ?? $env)) && '' !== $env) {
+                        if (false === $env = $vars[$name] ?? $env) {
+                            continue;
+                        }
+                        if ($env instanceof \Stringable) {
+                            $this->loadedVars[array_key_last($this->loadedVars)][$name] = $env = (string) $env;
+                        }
+                        if ('' !== ($env ?? '')) {
                             $ended = false;
                             break;
                         }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/EnvVarProcessorTest.php b/src/Symfony/Component/DependencyInjection/Tests/EnvVarProcessorTest.php
@@ -808,6 +808,12 @@ public function loadEnvVars(): array
                     return [
                         'FOO_ENV_LOADER' => '123',
                         'BAZ_ENV_LOADER' => '',
+                        'LAZY_ENV_LOADER' => new class() {
+                            public function __toString()
+                            {
+                                return '';
+                            }
+                        },
                     ];
                 }
             };
@@ -819,6 +825,12 @@ public function loadEnvVars(): array
                         'FOO_ENV_LOADER' => '234',
                         'BAR_ENV_LOADER' => '456',
                         'BAZ_ENV_LOADER' => '567',
+                        'LAZY_ENV_LOADER' => new class() {
+                            public function __toString()
+                            {
+                                return '678';
+                            }
+                        },
                     ];
                 }
             };
@@ -841,6 +853,9 @@ public function loadEnvVars(): array
         $result = $processor->getEnv('string', 'FOO_ENV_LOADER', function () {});
         $this->assertSame('123', $result); // check twice
 
+        $result = $processor->getEnv('string', 'LAZY_ENV_LOADER', function () {});
+        $this->assertSame('678', $result);
+
         unset($_ENV['BAZ_ENV_LOADER']);
         unset($_ENV['BUZ_ENV_LOADER']);
     }
diff --git a/src/Symfony/Component/String/LazyString.php b/src/Symfony/Component/String/LazyString.php
@@ -39,7 +39,7 @@ public static function fromCallable(callable|array $callback, mixed ...$argument
                     $callback[1] ??= '__invoke';
                 }
                 $value = $callback(...$arguments);
-                $callback = self::getPrettyName($callback);
+                $callback = !\is_scalar($value) && !$value instanceof \Stringable ? self::getPrettyName($callback) : 'callable';
                 $arguments = null;
             }
 

Original file line number	Diff line number	Diff line change
`@@ -19,7 +19,7 @@`
`19`	`19`	`interface EnvVarLoaderInterface`
`20`	`20`	`{`
`21`	`21`	`/**`
`22`		`- * @return string[] Key/value pairs that can be accessed using the regular "%env()%" syntax`
	`22`	`+ * @return array<string\|\Stringable> Key/value pairs that can be accessed using the regular "%env()%" syntax`
`23`	`23`	`*/`
`24`	`24`	`public function loadEnvVars(): array;`
`25`	`25`	`}`
Original file line number	Diff line number	Diff line change
`@@ -39,7 +39,7 @@ public static function fromCallable(callable\|array $callback, mixed ...$argument`
`39`	`39`	`$callback[1] ??= '__invoke';`
`40`	`40`	`}`
`41`	`41`	`$value = $callback(...$arguments);`
`42`		`- $callback = self::getPrettyName($callback);`
	`42`	`+ $callback = !\is_scalar($value) && !$value instanceof \Stringable ? self::getPrettyName($callback) : 'callable';`
`43`	`43`	`$arguments = null;`
`44`	`44`	`}`
`45`	`45`