Let users install the extensions without actually enabling them (#449)

Test: apcu, apcu_bc, blackfire, event, ioncube_loader, sourceguardian, http, memcached, snuffleupagus, xdebug

README.md

@@ -299,6 +299,7 @@ Here's the list of all the supported environment variables:
 | Extension | Environment variable | Description |
 |---|---|---|
 | | `IPE_FIX_CACERTS=1` | Old Alpine Linux (3.7 and 3.8) and Debian (Jessie and Stretch) versions don't work anymore with websites whose HTTPS certificate has been signed by Let's Encrypt ([more details here](https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/)).<br /> By setting this environment variable, `install-php-extensions` will fix this issue |
+| | `IPE_DONT_ENABLE=1` | By default the script will install and enable the extensions.<br />If you want to only install them (without enabling them) you can set this environment variable.<br />To enable the extensions at a later time you can execute the command `docker-php-ext-enable-<extension>` (for example: `docker-php-ext-enable-xdebug`).<br />**Beware**: installing some PHP extensions require that other PHP extensions are already enabled, so use this feature wisely. |
 | | `IPE_KEEP_SYSPKG_CACHE=1` | By default the script will clear the apt/apk/pear cache in order to save disk space. You can disable it by setting this environment variable |
 | lzf | `IPE_LZF_BETTERCOMPRESSION=1` | By default `install-php-extensions` compiles the `lzf` extension to prefer speed over size; you can use this environment variable to compile it preferring size over speed |
 | event | `IPE_EVENT_NAMESPACE=`... | By default the `event` classes are defined in the root namespace. You can use this environment variable to specify a custom namespace |

install-php-extensions

@@ -1257,6 +1257,44 @@ getCompilationProcessorCount() {
 	esac
 }
 
+# Enable a PHP extension
+#
+# Arguments:
+#   $1: the name of the PHP extension to be enabled
+#   $2: the name of the INI file (optional)
+#   $3: custom contents of the INI file (optional)
+enablePhpExtension() {
+	enablePhpExtension_cmd='docker-php-ext-enable'
+	enablePhpExtension_iniFile="$PHP_INI_DIR/conf.d"
+	if test -n "${2:-}"; then
+		enablePhpExtension_cmd="$enablePhpExtension_cmd --ini-name $2"
+		enablePhpExtension_iniFile="$enablePhpExtension_iniFile/$2"
+	else
+		enablePhpExtension_iniFile="$enablePhpExtension_iniFile/docker-php-ext-$1.ini"
+	fi
+	enablePhpExtension_cmd="$enablePhpExtension_cmd $1"
+	case "${IPE_DONT_ENABLE:-}" in
+		1 | y* | Y*)
+			enablePhpExtension_enableCommand="/usr/local/bin/docker-php-ext-enable-$1"
+			printf '#!/bin/sh\n\n' >"$enablePhpExtension_enableCommand"
+			if test -z "${3-}"; then
+				printf '%s\n' "$enablePhpExtension_cmd" >>"$enablePhpExtension_enableCommand"
+			else
+				printf 'cat <<EOT >%s\n%s\nEOT\n' "$enablePhpExtension_iniFile" "$3" >>"$enablePhpExtension_enableCommand"
+			fi
+			chmod +x "$enablePhpExtension_enableCommand"
+			printf '## Extension %s not enabled.\nYou can enable it by running the following command:\n%s\n\n' "$1" "$(basename "$enablePhpExtension_enableCommand")"
+			;;
+		*)
+			if test -z "${3-}"; then
+				$enablePhpExtension_cmd
+			else
+				printf '%s\n' "$3" >"$enablePhpExtension_iniFile"
+			fi
+			;;
+	esac
+}
+
 # Mark the pre-installed APT/APK packages as used
 # that way they won't be uninstalled by accident
 markPreinstalledPackagesAsUsed() {
@@ -2810,33 +2848,32 @@ installRemoteModule() {
 	case "$installRemoteModule_module" in
 		apcu_bc)
 			# apcu_bc must be loaded after apcu
-			docker-php-ext-enable --ini-name "xx-php-ext-$installRemoteModule_module.ini" apc
+			enablePhpExtension apc "xx-php-ext-$installRemoteModule_module.ini"
 			;;
 		blackfire)
-			printf "extension=blackfire.so\nblackfire.agent_socket=tcp://blackfire:8307\n" >"$PHP_INI_DIR/conf.d/docker-php-ext-$installRemoteModule_module.ini"
+			enablePhpExtension "$installRemoteModule_module" '' "$(printf 'extension=blackfire.so\nblackfire.agent_socket=tcp://blackfire:8307')"
 			;;
 		event)
 			# event must be loaded after sockets
-			docker-php-ext-enable --ini-name "xx-php-ext-$installRemoteModule_module.ini" "$installRemoteModule_module"
+			enablePhpExtension "$installRemoteModule_module" "xx-php-ext-$installRemoteModule_module.ini"
 			;;
 		ioncube_loader | sourceguardian)
 			# On PHP 5.5, docker-php-ext-enable fails to detect that ionCube Loader is a Zend Extension
 			if test $PHP_MAJMIN_VERSION -le 505; then
-				printf 'zend_extension=%s/%s.so\n' "$(getPHPExtensionsDir)" "$installRemoteModule_module" >"$PHP_INI_DIR/conf.d/docker-php-ext-$installRemoteModule_module.ini"
+				enablePhpExtension "$installRemoteModule_module" '' "$(printf 'zend_extension=%s/%s.so' "$(getPHPExtensionsDir)" "$installRemoteModule_module")"
 			else
-				docker-php-ext-enable "$installRemoteModule_module"
+				enablePhpExtension "$installRemoteModule_module"
 			fi
 			;;
 		http | memcached)
 			# http must be loaded after raphf and propro, memcached must be loaded after msgpack
-			docker-php-ext-enable --ini-name "xx-php-ext-$installRemoteModule_module.ini" "$installRemoteModule_module"
+			enablePhpExtension "$installRemoteModule_module" "xx-php-ext-$installRemoteModule_module.ini"
 			;;
 		snuffleupagus)
-			docker-php-ext-enable "$installRemoteModule_module"
+			enablePhpExtension "$installRemoteModule_module" '' "$(printf 'extension=%s/%s.so\nsp.configuration_file=%s' "$(getPHPExtensionsDir)" "$installRemoteModule_module" "$PHP_INI_DIR/conf.d/snuffleupagus.rules")"
-			printf 'sp.configuration_file=%s\n' "$PHP_INI_DIR/conf.d/snuffleupagus.rules" >>"$PHP_INI_DIR/conf.d/docker-php-ext-snuffleupagus.ini"
 			;;
 		*)
-			docker-php-ext-enable "$installRemoteModule_module"
+			enablePhpExtension "$installRemoteModule_module"
 			;;
 	esac
 }