From: Martin Mares <mj@ucw.cz>
Date: Sun, 16 Oct 2011 19:24:17 +0000 (+0200)
Subject: When zone contents do not change, version number is not incremented
X-Git-Tag: v4.0~6
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=0ec444f01f4f7932698896f40e22a70fe1357f1f;p=nsc-5.git

When zone contents do not change, version number is not incremented

Replaced direct calls to M4 from the Makefile by calling an auxiliary
script (generated by m4/mkgenzone.m4), which calculates a MD5 hash of
a (suitably normalized) zone file and compares it with a cached hash
of the current version.

The downside is that we run M4 twice on each changed zone. If it ever
causes any harm, we can generate the zone once and move updating of the
version number to the shell script, too.

Based on a patch by Vaclav Ovsik.
---

diff --git a/NEWS b/NEWS
index 8062980..a4da74d 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,3 @@
-
   o  Added FORWARDING macro for generating forward-only zones.
   o  Added BLACKHOLE macro for blackhole zones as per RFC 6303.
      Blackhole zones in example cf/domains updated to use this macro.
@@ -7,25 +6,27 @@
      appropriate options to BIND config file and include the part
      with the list of zones generated by NSC from there. This means
      that BIND_OPTIONS, FORWARD and SLAVE are gone.
+  o  When contents of a zone do not change, the version number is
+     not incremented.
 
-Version 3.1  [21-05-2008]
+Version 3.1  [2008-05-21]
 
   o  Fixes for compatibility problems with recent versions of GNU m4.
   o  Added support for TXT, RP and SRV records.
 
-Version 3.0.1  [22-11-2006]
+Version 3.0.1  [2006-11-22]
 
   Fixed bugs in in the FORWARD and SLAVE macros, causing it to
   generate bogus output sometimes.
 
-Version 3.0  [20-02-2005]
+Version 3.0  [2005-02-20]
 
   One year of testing should be good enough, so releasing 2.99b as 3.0
   with almost no changes. The only one is:
 
   o  ZONE_OPTIONS macro added, allowing to add custom options to zones.
 
-Version 2.99b  [21-12-2003]
+Version 2.99b  [2003-12-21]
 
   This version has been almost rewritten from scratch. The syntax
   of configuration files is incompatible with the previous versions,
@@ -40,7 +41,7 @@ Version 2.99b  [21-12-2003]
   o  Cleaned up names of all macros, the namespaces are now clearly
      defined.
 
-Version 2.3  [27-06-2001]
+Version 2.3  [2001-06-27]
 
   o  Global parameters (hostmaster mail address etc.) can be set
      in cf/config now.
@@ -48,7 +49,7 @@ Version 2.3  [27-06-2001]
   o  Fixed bugs in convert script.
   o  Generate $TTL to make new releases of bind happy.
 
-Version 2.2  [11-09-1999]
+Version 2.2  [1999-09-11]
 
   o  Corrected localhost records.
   o  Name-server restart command can be overriden (useful for setups
diff --git a/TODO b/TODO
index e0da11b..bf97c01 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,3 @@
 freebsd: don't use `-f' in hostname
-if a zone doesn't change, don't bump the version
 
-BIND9: options
 BIND9: `bak' must be owned by the bind user
diff --git a/bin/nsconfig b/bin/nsconfig
index c23ebc7..14d34ed 100755
--- a/bin/nsconfig
+++ b/bin/nsconfig
@@ -13,4 +13,6 @@ if [ ! -f $DOMAINS ] ; then
 	fi
 
 $M4 m4/mkconf.m4 $DOMAINS >named.conf
-$M4 -DM4=$M4 m4/mkmf.m4 $DOMAINS >Makefile
+$M4 m4/mkmf.m4 $DOMAINS >Makefile
+$M4 -DM4=$M4 m4/mkgenzone.m4 >bin/genzone
+chmod +x bin/genzone
diff --git a/m4/dnslib.m4 b/m4/dnslib.m4
index f6fc63c..9fc84fe 100644
--- a/m4/dnslib.m4
+++ b/m4/dnslib.m4
@@ -92,6 +92,7 @@ define(`CFDIR', `cf')
 define(`ZONEDIR', `zone')
 define(`BAKDIR', `bak')
 define(`VERSDIR', `ver')
+define(`HASHDIR', `hash')
 define(`ROOTCACHE', `root.cache')
 
 define(`REFRESH', HOURS(8))
diff --git a/m4/mkgenzone.m4 b/m4/mkgenzone.m4
new file mode 100644
index 0000000..0d898f4
--- /dev/null
+++ b/m4/mkgenzone.m4
@@ -0,0 +1,25 @@
+dnl ###
+dnl ### NSC -- Zone Generating Script Builder
+dnl ### (c) 2011 Martin Mares <mj@ucw.cz>
+dnl ###
+include(m4/dnslib.m4)
+changecom(REM)
+divert(0)dnl
+#!/bin/sh
+# Please do not modify this script, it is automatically generated by m4/mkgenzone.m4
+
+set -e
+Z=`$'1
+shift
+mkdir -p HASHDIR
+CURRENT_HASH=$(M4 -DHASHING m4/nsc.m4 "$@" | md5sum | cut -d " " -f1)
+PREV_HASH=$(if [ -s HASHDIR/$Z ] ; then cat HASHDIR/$Z ; fi)
+if [ "X$CURRENT_HASH" = "X$PREV_HASH" ] ; then
+	echo "-- $Z: No changes"
+	touch ZONEDIR/$Z HASHDIR/$Z
+else
+	M4 -DVERS=VERSDIR/$Z m4/nsc.m4 "$@" >ZONEDIR/$Z.new
+	mv ZONEDIR/$Z.new ZONEDIR/$Z
+	echo "** $Z: New version $(sed -e "s/^;;; VERSION: //; t; d" ZONEDIR/$Z)"
+	echo $CURRENT_HASH >HASHDIR/$Z
+fi
diff --git a/m4/mkmf.m4 b/m4/mkmf.m4
index fd4ca87..0f0b5f6 100644
--- a/m4/mkmf.m4
+++ b/m4/mkmf.m4
@@ -11,7 +11,7 @@ define(`PRIMARIES', `')
 define(`nsc_prepend_cf_one', ` 'CFDIR/`nsc_file_name($1)')
 define(`nsc_prepend_cf_multi', `nsc_iterate(`nsc_prepend_cf_one', $@)')
 define(`PRIMARY', `divert(0)ZONEDIR/nsc_file_name($1):nsc_prepend_cf_multi($@) $(DDEPS)
-	`$'(`M4') -DVERS=VERSDIR/nsc_file_name($1) `$'(NSC)nsc_prepend_cf_multi($@) >ZONEDIR/nsc_file_name($1)
+	@bin/genzone nsc_file_name($1)`'nsc_prepend_cf_multi($@)
 
 divert(-1)
 define(`PRIMARIES', PRIMARIES ZONEDIR/nsc_file_name($1))
@@ -37,10 +37,10 @@ divert(0)VERSDIR/.version: CFDIR/domains ROOTCACHE`'PRIMARIES`'ifdef(`NEED_BLACK
 ')dnl
 
 clean:
-	find BAKDIR ZONEDIR -maxdepth 1 -type f | xargs rm -f
+	find BAKDIR ZONEDIR HASHDIR -maxdepth 1 -type f | xargs rm -f
 
 clobber: clean
-	rm -f Makefile named.conf
+	rm -f Makefile named.conf bin/genzone
 
 distclean: clobber
 	find VERSDIR -maxdepth 1 -type f | xargs rm -f
@@ -53,9 +53,7 @@ divert(0)dnl
 `#'	Please don't edit manually
 `#'
 
-`M4'=M4
-NSC=m4/nsc.m4
-DDEPS=`$'(NSC) m4/dnslib.m4 cf/config
+DDEPS=m4/nsc.m4 m4/dnslib.m4 cf/config
 
 all: VERSDIR/.version
 m4wrap(`nsc_cleanup')
diff --git a/m4/nsc.m4 b/m4/nsc.m4
index 80d091e..224512d 100644
--- a/m4/nsc.m4
+++ b/m4/nsc.m4
@@ -8,6 +8,8 @@ include(m4/dnslib.m4)
 
 # Version number
 
+ifdef(`HASHING', `define(`VERSION',`YYYYMMDDNN')', `
+
 ifdef(`VERS',`',`nsc_fatal_error(`VERS macro not defined')')
 
 define(TODAY_CODE, translit(esyscmd(`date +"%Y%m%d"'),`
@@ -21,6 +23,8 @@ syscmd(echo >VERS "`define'(`LAST_TODAY_CODE',TODAY_CODE) `define'(`SUBVER_NUM',
 ifelse(eval(SUBVER_NUM > 99),1,`nsc_fatal_error(`Too many zone changes in a single day, you must tweak 'VERS` manually')')
 define(`VERSION',TODAY_CODE`'format(`%02d', SUBVER_NUM))
 
+')
+
 # Record names
 
 define(nsc_set_name, `define(`CURRENT_NAME', nsc_corr_dot($1))define(`PRINT_NAME', CURRENT_NAME)')
@@ -155,6 +159,7 @@ m4wrap(`nsc_cleanup')
 
 divert(0)dnl
 `;;;' Primary zone file
-`;;;' Generated by NSCVER (nsc.m4) on CURRENT_DATE
+`;;;' Generated by NSCVER (nsc.m4) on ifdef(`HASHING', ``CURRENT_DATE'', `CURRENT_DATE')
 `;;;' Please do not edit manually
+`;;;' `VERSION': VERSION
 `'