New env var: IPE_DEBUG (turn on debug) (#695)

README.md

@@ -385,6 +385,7 @@ Here's the list of all the supported environment variables:
 
 | Extension | Environment variable | Description |
 |---|---|---|
+| | `IPE_DEBUG=1` | By setting this environment variable, the script will print all the commands it executes (it will be very verbose, useful only for debug purposes) |
 | | `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 |

install-php-extensions

@@ -12,6 +12,10 @@
 set -o errexit
 set -o nounset
 
+if test "${IPE_DEBUG:-}" = "1"; then
+	set -x
+fi
+
 if ! which docker-php-ext-configure >/dev/null || ! which docker-php-ext-enable >/dev/null || ! which docker-php-ext-install >/dev/null || ! which docker-php-source >/dev/null; then
 	printf 'The script %s is meant to be used with official Docker PHP Images - https://hub.docker.com/_/php\n' "$0" >&2
 	exit 1