package/busybox: add httpd server startup script

In order to remove thttpd package from Buildroot, we have to replace it
from our testsuite (TestWget and TestLibCurl).

Busybox provide an httpd server applet but it's not enabled in our
default busybox configuration.

For the sake of those tests, add a new busybox option to build and
install the Busybox's httpd server and its init script.

Import S90thttpd from thttpd package to S90httpd but with some changes
following S01syslogd init script as a reference [1].

[1] https://gitlab.com/buildroot.org/buildroot/-/commit/3dc80614442cc3942a372a8c31abd22c1bc96241

Cc: Julien Olivain <ju.o@free.fr>
Cc: Fiona Klute (WIWA) <fiona.klute@gmx.de>
Signed-off-by: Romain Naour <romain.naour@smile.fr>
Reviewed-by: Fiona Klute <fiona.klute@gmx.de>
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>

package/busybox/Config.in

@@ -69,6 +69,12 @@ config BR2_PACKAGE_BUSYBOX_INDIVIDUAL_BINARIES
 comment "Busybox individual binaries need a toolchain w/ dynamic library"
 	depends on BR2_STATIC_LIBS
 
+config BR2_PACKAGE_BUSYBOX_HTTPD
+	bool "Install the httpd server startup script"
+	help
+	  Install the httpd server startup script,
+	  that just start at the boot the busybox httpd server
+
 config BR2_PACKAGE_BUSYBOX_WATCHDOG
 	bool "Install the watchdog daemon startup script"
 	help

package/busybox/S90httpd

@@ -0,0 +1,59 @@
+#!/bin/sh
+
+DAEMON="httpd"
+PIDFILE="/var/run/$DAEMON.pid"
+
+HTTPD_ARGS="-h /var/www/data"
+
+# shellcheck source=/dev/null
+[ -r "/etc/default/$DAEMON" ] && . "/etc/default/$DAEMON"
+
+# BusyBox' httpd does not create a pidfile, so pass "-f" in the command line
+# and use "--make-pidfile" to instruct start-stop-daemon to create one.
+start() {
+	printf 'Starting %s: ' "$DAEMON"
+	# shellcheck disable=SC2086 # we need the word splitting
+	start-stop-daemon --start --background --quiet --make-pidfile \
+		--pidfile "$PIDFILE" --exec "/usr/sbin/$DAEMON" \
+		-- -f $HTTPD_ARGS
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+	return "$status"
+}
+
+stop() {
+	printf 'Stopping %s: ' "$DAEMON"
+	start-stop-daemon --stop --quiet --pidfile "$PIDFILE"
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+	while start-stop-daemon --stop --test --quiet --pidfile "$PIDFILE" \
+		--exec "/usr/sbin/$DAEMON"; do
+		sleep 0.1
+	done
+	rm -f "$PIDFILE"
+	return "$status"
+}
+
+restart() {
+	stop
+	start
+}
+
+case "$1" in
+	start|stop|restart)
+		"$1";;
+	reload)
+		# Restart, since there is no true "reload" feature.
+		restart;;
+	*)
+		echo "Usage: $0 {start|stop|restart|reload}"
+		exit 1
+esac

package/busybox/busybox.mk

@@ -258,6 +258,19 @@ define BUSYBOX_SET_SELINUX
 endef
 endif
 
+ifeq ($(BR2_PACKAGE_BUSYBOX_HTTPD),y)
+define BUSYBOX_SET_HTTPD
+	$(call KCONFIG_ENABLE_OPT,CONFIG_HTTPD)
+endef
+define BUSYBOX_INSTALL_HTTPD_SCRIPT
+	if grep -q CONFIG_HTTPD=y $(@D)/.config; then \
+		mkdir -p $(TARGET_DIR)/var/www/data ;\
+		$(INSTALL) -m 0755 -D package/busybox/S90httpd \
+			$(TARGET_DIR)/etc/init.d/S90httpd ; \
+	fi
+endef
+endif
+
 # enable relevant options to allow the Busybox less applet to be used
 # as a systemd pager
 ifeq ($(BR2_PACKAGE_SYSTEMD):$(BR2_PACKAGE_LESS),y:)
@@ -418,6 +431,7 @@ define BUSYBOX_KCONFIG_FIXUP_CMDS
 	$(BUSYBOX_SET_WATCHDOG)
 	$(BUSYBOX_SET_SELINUX)
 	$(BUSYBOX_SET_LESS_FLAGS)
+	$(BUSYBOX_SET_HTTPD)
 	$(BUSYBOX_SET_INDIVIDUAL_BINARIES)
 	$(BUSYBOX_DISABLE_IP_LINK_CAN)
 	$(PACKAGES_BUSYBOX_CONFIG_FIXUPS)
@@ -447,6 +461,7 @@ define BUSYBOX_INSTALL_INIT_OPENRC
 	$(BUSYBOX_INSTALL_IFPLUGD_SCRIPT)
 	$(BUSYBOX_INSTALL_CROND_SCRIPT)
 	$(BUSYBOX_INSTALL_TELNET_SCRIPT)
+	$(BUSYBOX_INSTALL_HTTPD_SCRIPT)
 endef
 
 define BUSYBOX_INSTALL_INIT_SYSTEMD
@@ -461,6 +476,7 @@ define BUSYBOX_INSTALL_INIT_SYSV
 	$(BUSYBOX_INSTALL_IFPLUGD_SCRIPT)
 	$(BUSYBOX_INSTALL_CROND_SCRIPT)
 	$(BUSYBOX_INSTALL_TELNET_SCRIPT)
+	$(BUSYBOX_INSTALL_HTTPD_SCRIPT)
 endef
 
 # Checks to give errors that the user can understand