From 4de057cf19426a096104547cea0e48d250739c17 Mon Sep 17 00:00:00 2001
From: Mistral OZ - MIO <m.oz@thecodingmachine.com>
Date: Tue, 3 Nov 2026 18:07:13 +0100
Subject: [PATCH] Detect the changes of the PHP_* variables in the php proxy
 without starting PHP

---
 CHANGELOG.md                        |  3 +++
 Dockerfile.slim.apache              |  4 ++--
 Dockerfile.slim.cli                 |  4 ++--
 Dockerfile.slim.fpm                 |  4 ++--
 tests-suite/php-ini.sh              |  6 +++++
 utils/Dockerfile.slim.blueprint     |  4 ++--
 utils/check_php_env_var_changes.php | 34 -----------------------------
 utils/docker-entrypoint-as-root.sh  |  4 ++--
 utils/php_env_fingerprint.sh        |  7 ++++++
 utils/php_env_var_cache.php         |  3 ---
 utils/php_proxy.sh                  | 24 ++++++++++----------
 11 files changed, 38 insertions(+), 59 deletions(-)
 delete mode 100644 utils/check_php_env_var_changes.php
 create mode 100644 utils/php_env_fingerprint.sh
 delete mode 100644 utils/php_env_var_cache.php

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b5d37fb..90c16afd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 
 ### Minor changes
 
+* **2026-11-03**
+  * The `php` command is about 20 ms faster on each call: it detects the changes of the `PHP_*` environment variables without starting PHP a first time. The configuration is now also regenerated when a `PHP_*` variable is removed
+
 * **2026-10-23**
   * Security: php2shell is fixed in the arm64 images too, now that the fixed PHP packages are published for arm64. The php2shell test fails again for a vulnerable image on every architecture
   * The tags of the PHP patch versions (e.g. `8.5.12-v5-cli`) are published again: they were no longer published since 2025-12-10. The `X.Y-v5-*` tags are not affected
diff --git a/Dockerfile.slim.apache b/Dockerfile.slim.apache
index 0a516ce8..f7cecd31 100644
--- a/Dockerfile.slim.apache
+++ b/Dockerfile.slim.apache
@@ -118,8 +118,8 @@ COPY utils/select_composer_version.sh /usr/local/bin/select_composer_version.sh
 COPY utils/utils.php /usr/local/bin/utils.php
 RUN mv /usr/bin/php /usr/bin/real_php
 COPY utils/php_proxy.sh /usr/bin/php
-COPY utils/check_php_env_var_changes.php /usr/local/bin/check_php_env_var_changes.php
-COPY utils/php_env_var_cache.php /opt/php_env_var_cache.php
+COPY utils/php_env_fingerprint.sh /usr/local/bin/php_env_fingerprint.sh
+RUN touch /opt/php_env_fingerprint
 COPY utils/generate_conf.php /usr/local/bin/generate_conf.php
 COPY utils/setup_extensions.php /usr/local/bin/setup_extensions.php
 
diff --git a/Dockerfile.slim.cli b/Dockerfile.slim.cli
index ae1d0737..92e66fca 100644
--- a/Dockerfile.slim.cli
+++ b/Dockerfile.slim.cli
@@ -118,8 +118,8 @@ COPY utils/select_composer_version.sh /usr/local/bin/select_composer_version.sh
 COPY utils/utils.php /usr/local/bin/utils.php
 RUN mv /usr/bin/php /usr/bin/real_php
 COPY utils/php_proxy.sh /usr/bin/php
-COPY utils/check_php_env_var_changes.php /usr/local/bin/check_php_env_var_changes.php
-COPY utils/php_env_var_cache.php /opt/php_env_var_cache.php
+COPY utils/php_env_fingerprint.sh /usr/local/bin/php_env_fingerprint.sh
+RUN touch /opt/php_env_fingerprint
 COPY utils/generate_conf.php /usr/local/bin/generate_conf.php
 COPY utils/setup_extensions.php /usr/local/bin/setup_extensions.php
 
diff --git a/Dockerfile.slim.fpm b/Dockerfile.slim.fpm
index 0c379670..619b8b56 100644
--- a/Dockerfile.slim.fpm
+++ b/Dockerfile.slim.fpm
@@ -118,8 +118,8 @@ COPY utils/select_composer_version.sh /usr/local/bin/select_composer_version.sh
 COPY utils/utils.php /usr/local/bin/utils.php
 RUN mv /usr/bin/php /usr/bin/real_php
 COPY utils/php_proxy.sh /usr/bin/php
-COPY utils/check_php_env_var_changes.php /usr/local/bin/check_php_env_var_changes.php
-COPY utils/php_env_var_cache.php /opt/php_env_var_cache.php
+COPY utils/php_env_fingerprint.sh /usr/local/bin/php_env_fingerprint.sh
+RUN touch /opt/php_env_fingerprint
 COPY utils/generate_conf.php /usr/local/bin/generate_conf.php
 COPY utils/setup_extensions.php /usr/local/bin/setup_extensions.php
 
diff --git a/tests-suite/php-ini.sh b/tests-suite/php-ini.sh
index 9929de7e..17075640 100755
--- a/tests-suite/php-ini.sh
+++ b/tests-suite/php-ini.sh
@@ -38,6 +38,12 @@ test_environmentErrorReporting() {
   [[ "$RESULT" == "error_reporting => 3 => 3" ]]
   assert_equals "error_reporting => 3 => 3" "$RESULT" "Wrong Environment error reporting"
 }
+test_environmentChangedAfterStart() {
+  RESULT="$(docker run ${RUN_OPTIONS} --rm \
+    "${REPO}:${TAG_PREFIX}${PHP_VERSION}-${BRANCH}-slim-${BRANCH_VARIANT}${ARCH_SUFFIX}" \
+    bash -c 'PHP_INI_MEMORY_LIMIT=512M php -r "echo ini_get(\"memory_limit\"), \" \";"; php -r "echo ini_get(\"memory_limit\");"')"
+  assert_equals "512M -1" "$RESULT" "The configuration is not regenerated when a PHP_* variable is added or removed"
+}
 ############################################################
 ## PHP_INI_SESSION__SAVE_PATH
 ## Tests that environment variables with an equal sign are correctly handled
diff --git a/utils/Dockerfile.slim.blueprint b/utils/Dockerfile.slim.blueprint
index 0f4e75f5..a621a9e5 100644
--- a/utils/Dockerfile.slim.blueprint
+++ b/utils/Dockerfile.slim.blueprint
@@ -117,8 +117,8 @@ COPY utils/select_composer_version.sh /usr/local/bin/select_composer_version.sh
 COPY utils/utils.php /usr/local/bin/utils.php
 RUN mv /usr/bin/php /usr/bin/real_php
 COPY utils/php_proxy.sh /usr/bin/php
-COPY utils/check_php_env_var_changes.php /usr/local/bin/check_php_env_var_changes.php
-COPY utils/php_env_var_cache.php /opt/php_env_var_cache.php
+COPY utils/php_env_fingerprint.sh /usr/local/bin/php_env_fingerprint.sh
+RUN touch /opt/php_env_fingerprint
 COPY utils/generate_conf.php /usr/local/bin/generate_conf.php
 COPY utils/setup_extensions.php /usr/local/bin/setup_extensions.php
 
diff --git a/utils/check_php_env_var_changes.php b/utils/check_php_env_var_changes.php
deleted file mode 100644
index 058f3ebb..00000000
--- a/utils/check_php_env_var_changes.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-
-$phpEnvVarCache = include '/opt/php_env_var_cache.php';
-$envVars = getenv();
-$shouldGenerateConfig = false;
-$phpEnvVar = [];
-
-foreach($envVars as $key => $value) {
-    if (substr($key, 0, strlen('PHP_')) === 'PHP_') {
-        if (!isset($phpEnvVarCache[$key])) {
-            // The env var does not exist in the cache.
-            $shouldGenerateConfig = true;
-        } else if ($phpEnvVarCache[$key] !== $value) {
-            // The value has changed.
-            $shouldGenerateConfig = true;
-        }
-
-        $phpEnvVar[$key] = $value;
-    }
-}
-
-if ($shouldGenerateConfig === false) {
-    echo "0";
-    exit(0);
-}
-
-$cacheFileContent = '<?php' . PHP_EOL . 'return ' . var_export($phpEnvVar, true) . ';' ;
-$result = file_put_contents('/opt/php_env_var_cache.php', $cacheFileContent);
-if ($result === false) {
-    exit(1);
-}
-
-echo "1";
-exit(0);
\ No newline at end of file
diff --git a/utils/docker-entrypoint-as-root.sh b/utils/docker-entrypoint-as-root.sh
index 947b0d41..ec6cdcb4 100755
--- a/utils/docker-entrypoint-as-root.sh
+++ b/utils/docker-entrypoint-as-root.sh
@@ -149,8 +149,8 @@ fi
 unset DOCKER_FOR_MAC_REMOTE_HOST
 unset REMOTE_HOST_FOUND
 
-sudo chown docker:docker /opt/php_env_var_cache.php
-/usr/bin/real_php -d display_errors=stderr /usr/local/bin/check_php_env_var_changes.php &> /dev/null
+source /usr/local/bin/php_env_fingerprint.sh
+php_env_fingerprint > /opt/php_env_fingerprint
 
 /usr/bin/real_php -d display_errors=stderr /usr/local/bin/generate_conf.php > /etc/php/${PHP_VERSION}/mods-available/generated_conf.ini
 PHP_VERSION="${PHP_VERSION}" /usr/bin/real_php -d display_errors=stderr /usr/local/bin/setup_extensions.php | sudo bash
diff --git a/utils/php_env_fingerprint.sh b/utils/php_env_fingerprint.sh
new file mode 100644
index 00000000..a59a5529
--- /dev/null
+++ b/utils/php_env_fingerprint.sh
@@ -0,0 +1,7 @@
+# Fingerprint of the PHP_* environment variables the PHP configuration is generated from
+php_env_fingerprint() {
+    local name
+    for name in "${!PHP_@}"; do
+        printf '%s=%s\0' "$name" "${!name}"
+    done | md5sum
+}
diff --git a/utils/php_env_var_cache.php b/utils/php_env_var_cache.php
deleted file mode 100644
index 0b67a5fe..00000000
--- a/utils/php_env_var_cache.php
+++ /dev/null
@@ -1,3 +0,0 @@
-<?php
-
-return [];
diff --git a/utils/php_proxy.sh b/utils/php_proxy.sh
index f1ba90cf..b29307dd 100755
--- a/utils/php_proxy.sh
+++ b/utils/php_proxy.sh
@@ -1,21 +1,21 @@
 #!/bin/bash
 
-# Users that cannot use sudo run PHP with the current configuration
-if ! sudo -n chown docker:docker /opt/php_env_var_cache.php 2> /dev/null; then
+source /usr/local/bin/php_env_fingerprint.sh
+
+# The configuration is regenerated only when the PHP_* environment variables changed since its last generation
+FINGERPRINT=$(php_env_fingerprint)
+read -r GENERATED_FINGERPRINT < /opt/php_env_fingerprint
+if [[ "$FINGERPRINT" == "$GENERATED_FINGERPRINT" ]]; then
   exec /usr/bin/real_php "$@"
 fi
 
-REGENERATE=$(/usr/bin/real_php -d display_errors=stderr /usr/local/bin/check_php_env_var_changes.php)
-
-if [[ "$REGENERATE" != "0" ]] && [[ "$REGENERATE" != "1" ]]; then
-  >&2 echo "Unexpected PHP proxy output:"
-  >&2 echo $REGENERATE
-  exit 1
+# Users that cannot use sudo run PHP with the current configuration
+if ! sudo -n true 2> /dev/null; then
+  exec /usr/bin/real_php "$@"
 fi
 
-if [[ "$REGENERATE" == "1" ]]; then
-  /usr/bin/real_php -d display_errors=stderr /usr/local/bin/generate_conf.php | sudo tee "/etc/php/${PHP_VERSION}/mods-available/generated_conf.ini" > /dev/null
-  PHP_VERSION="${PHP_VERSION}" /usr/bin/real_php -d display_errors=stderr /usr/local/bin/setup_extensions.php | sudo bash
-fi
+/usr/bin/real_php -d display_errors=stderr /usr/local/bin/generate_conf.php | sudo tee "/etc/php/${PHP_VERSION}/mods-available/generated_conf.ini" > /dev/null
+PHP_VERSION="${PHP_VERSION}" /usr/bin/real_php -d display_errors=stderr /usr/local/bin/setup_extensions.php | sudo bash
+echo "$FINGERPRINT" | sudo tee /opt/php_env_fingerprint > /dev/null
 
 exec /usr/bin/real_php "$@"