php: fpm sapi: install php-fpm.conf

Install a custom php-fpm.conf instead of the stock one.

- Listening on /var/run/php-fpm.sock instead of TCP port so we can
  restrict access to webserver user www-data.
- Using ondemand pm, so PHP children are only started after a PHP
  request, instead of kept resident all the time.

Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/php/php-fpm.conf

@@ -0,0 +1,14 @@
+[www]
+# Only start children when there are requests to be processed
+pm = ondemand
+# Terminate them again after there haven't been any for 2 minutes
+pm.process_idle_timeout = 120s
+# Maximum number of children processing PHP requests concurrently
+pm.max_children = 5
+
+listen = /var/run/php-fpm.sock
+listen.owner = www-data
+listen.group = www-data
+user = www-data
+group = www-data
+

package/php/php.mk

@@ -264,6 +264,14 @@ define PHP_INSTALL_INIT_SYSTEMD
 	ln -fs ../../../../usr/lib/systemd/system/php-fpm.service \
 		$(TARGET_DIR)/etc/systemd/system/multi-user.target.wants/php-fpm.service
 endef
+
+define PHP_INSTALL_FPM_CONF
+	$(INSTALL) -D -m 0644 package/php/php-fpm.conf \
+		$(TARGET_DIR)/etc/php-fpm.conf
+	rm -f $(TARGET_DIR)/etc/php-fpm.conf.default
+endef
+
+PHP_POST_INSTALL_TARGET_HOOKS += PHP_INSTALL_FPM_CONF
 endif
 
 define PHP_EXTENSIONS_FIXUP