add syslog-ng to base image

rootfs/etc/syslog-ng/syslog-ng.conf

@@ -0,0 +1,24 @@
+@version: 3.7
+
+options {
+    stats_freq (0);
+    time_reopen (10);
+    chain_hostnames (off);
+    use_dns (no);
+    use_fqdn (no);
+    keep_hostname (yes);
+};
+
+source s_local {
+    unix-dgram("/dev/log");
+    internal();
+};
+
+destination catchall {
+	pipe("/dev/stdout");
+};
+
+log {
+    source(s_local);
+    destination(catchall);
+};