lxc-alpine: completely rewrite the template script

New template script is more readable and robust, uses cache and external
LXC config file as other templates.

Signed-off-by: Jakub Jirutka <jakub@jirutka.cz>

config/templates/Makefile.am

@@ -5,6 +5,8 @@ EXTRA_DIST = common.seccomp
 SUBDIRS = common.conf.d
 
 templatesconfig_DATA = \
+	alpine.common.conf \
+	alpine.userns.conf \
 	archlinux.common.conf \
 	archlinux.userns.conf \
 	centos.common.conf \

config/templates/alpine.common.conf.in

@@ -0,0 +1,20 @@
+# This derives from the global common config.
+lxc.include = @LXCTEMPLATECONFIG@/common.conf
+
+# Doesn't support consoles in /dev/lxc/.
+lxc.devttydir =
+
+# Drop another (potentially) harmful capabilities.
+lxc.cap.drop = audit_write
+lxc.cap.drop = ipc_owner
+lxc.cap.drop = mknod
+lxc.cap.drop = setfcap
+lxc.cap.drop = setpcap
+lxc.cap.drop = sys_nice
+lxc.cap.drop = sys_pacct
+lxc.cap.drop = sys_ptrace
+lxc.cap.drop = sys_rawio
+lxc.cap.drop = sys_resource
+lxc.cap.drop = sys_tty_config
+lxc.cap.drop = syslog
+lxc.cap.drop = wake_alarm

config/templates/alpine.userns.conf.in

@@ -0,0 +1,2 @@
+# This derives from the global userns config.
+lxc.include = @LXCTEMPLATECONFIG@/userns.conf

configure.ac

@@ -647,6 +647,8 @@ AC_CONFIG_FILES([
 	config/init/upstart/Makefile
 	config/etc/Makefile
 	config/templates/Makefile
+	config/templates/alpine.common.conf
+	config/templates/alpine.userns.conf
 	config/templates/archlinux.common.conf
 	config/templates/archlinux.userns.conf
 	config/templates/centos.common.conf