Built-in nscd into the docker image (a better dns caching service) (#3472)

docker/etc/sudoers

@@ -0,0 +1,31 @@
+#
+# This file MUST be edited with the 'visudo' command as root.
+#
+# Please consider adding local content in /etc/sudoers.d/ instead of
+# directly modifying this file.
+#
+# See the man page for details on how to write a sudoers file.
+#
+Defaults        env_reset
+Defaults        mail_badpass
+Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+
+# Host alias specification
+
+# User alias specification
+
+# Cmnd alias specification
+
+# User privilege specification
+root    ALL=(ALL:ALL) ALL
+
+# Allow members of group sudo to execute any command
+%sudo   ALL=(ALL:ALL) ALL
+
+# See sudoers(5) for more information on "#include" directives:
+
+#includedir /etc/sudoers.d
+
+# Allow `node` to control service (mainly for nscd)
+node ALL=(root) NOPASSWD: /usr/sbin/nscdservice
+node ALL=(root) NOPASSWD: /usr/sbin/service