netmagis.posyinst

#! /bin/sh

# netmagis.postinst : Netmagis upgrade script for debian packaging
# Copyright (C) 2013 Schplurtz le deboulonné <Schplurtz@laposte.net>
#
# This file is released under the GPL version 3 licence. See
# /usr/share/common-licenses/GPL-3 file for exact conditions

# summary of how this script can be called:
#        * <postinst> 'configure' <most-recently-configured-version>
#        * <old-postinst> 'abort-upgrade' <new version>
#        * <conflictor's-postinst> 'abort-remove' 'in-favour' <package>
#          <new-version>
#        * <postinst> 'abort-remove'
#        * <deconfigured's-postinst> 'abort-deconfigure' 'in-favour'
#          <failed-install-package> <version> 'removing'
#          <conflicting-package> <version>
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package


test configure = "$1" || exit 0
test "$2" || exit 0 # new installation : no upgrade

IFS="$(printf ' \t')
"
NL='
'

warn() { test "$*" && echo "$@" >&2; }
fatal() { warn "$@"; exit 1; }
pause() { local x; printf '%s Press return.' "$*"; read x; }

#setv var value
# setv x 4 #x=4
setv() { eval "$1=\$2"; }

#setp var var
# setp x y # x=$y
setp() { eval "$1=\$$2"; }

# ksql var
# kwote SQL. : Make content of var a proper SQL string
# a="toto l'héros des z'enfants"
# ksql a; # Now, a="'toto l''héros des z''enfants'"
ksql() {
  local __v __p="'"
  setp __v $1
  while :
  do
    : __v "$__v"
    : __p "$__p"
    case "$__v" in
    (*\'*)
      : case 1
      __p=$__p${__v%%\'*}"''"
      __v=${__v#*\'}
    ;;
    (*)
      : case 2
      break
    ;;
    esac
  done
  __p=$__p$__v"'"
  setp "$1" __p
}

# cfv conffile key [key...]
# Reads netmagis configfile and for each requested key
# found in config file, prints with correct sh quote
# assignments in the form key=val. This is rock solid
# and an be safely used even if values contain such
# chars as ' ` $ ; " etc...
#
# exple
# eval "$( cfv /etc/netmagis.conf dnsdbhost dnsdbport )"
# ==> eval "dnsdbhost='something' dnsdbport='somethingelse'"
cfv() {
  local i s configfile
  configfile=$1
  shift
  for i
  do
    s="$s\$1 == \"$i\" { traite() }
"
  done
  awk 'function traite(   a ) {
          a=$1
          sub( /^[ \t]*[^ \t]+[ \t]+/, "" )
          printf "%s=%s\n", a, shkwote( $0 );
       }
       function shkwote( s ) {
          gsub( /'\''/, "'\''\\'\'''\''", s )
         return "'\''" s "'\''"
       }'"
       $s
  "  "$configfile"
  #'
}

# loadconfig
# *)  sets global vars dnsdbhost dnsdbport .... to the value they have in
#     file /etc/netmagis.conf
# *)  fills $PGPASSFILE with db and password content
loadconfig() {
  local dnsdbpassword macdbpassword # don't want these in memory longer than needed
  eval "$(
    cfv /etc/netmagis.conf \
      dnsdbhost       \
      dnsdbport       \
      dnsdbname       \
      dnsdbuser       \
      dnsdbpassword   \
      macdbhost       \
      macdbport       \
      macdbname       \
      macdbuser       \
      macdbpassword   \

  )"
  {
    echo "${dnsdbhost}:${dnsdbport}:${dnsdbname}:${dnsdbuser}:${dnsdbpassword}"
    echo "${macdbhost}:${macdbport}:${macdbname}:${macdbuser}:${macdbpassword}"
  } >>"$PGPASSFILE"
}

# setdb dns|mac
# sets PG* env var so that next psql query targets dns db or mac db
setdb() {
  case "$1" in
  (dns)
    export PGDATABASE=$dnsdbname PGHOST=$dnsdbhost PGPORT=$dnsdbport PGUSER=$dnsdbuser
  ;;
  (mac)
    export PGDATABASE=$macdbname PGHOST=$macdbhost PGPORT=$macdbport PGUSER=$macdbuser
  ;;
  esac
}

# pipesql [other psql options]
# Runs any mix of sql and \ cmd from stdin
# cmd | pipesql
# pipesql < something
# exple
# echo '\d dns.*
#       select * from dns.rr limit 5' | pipesql -E
pipesql() {
  psql -q1twXA "$@"
}

# runsql [-pgopt opt [opt...] . ] cmd [cmd...]
# run any mix of sql and \ cmd
# exple
# runsql -pgopt -E . '\d dns.*
# '                    select '*' from dns.rr limit 5
runsql() {
  local args sep
  eval "sep=$(printf \\003)"
  test .-pgopt = ."$1" && {
    shift
    while test . != "$1"
    do
      args=$args${args:+$sep}$1
      shift
    done
    shift
  }
  IFS=$sep
  echo "$@" | pipesql $args
  IFS=$DIFS
}

#
# main Main MAIN
#


DIFS=$IFS
export PGPASSFILE=$(mktemp /tmp/totoXXXXX)
test -r "$PGPASSFILE" || fatal "can't read pgpassfile '$PGPASSFILE'"
trap "rm -rf $PGPASSFILE" EXIT

loadconfig

#
# Real job now.
#

TARGET_VERSION=22 # the db version we are trying to reach
setdb dns

runsql "SELECT 1" >/dev/null 2>&1 ||
  fatal "Cannot connect to database"

##################################################################
# first packaged version was 2.0
# 2.0 database has dns.dr_mbox table. table is dropped in 2.1+
# 2.1 database has no schemaversion key in global.config table
#     and the database column names are in French (so query for
#     'key' and 'value' in global.config table will fail).
# 2.2 and upper have a schemaversion key in global.config table
#     and column names are in english ( 'key' and 'value' ).
#
# upgrade sql scripts are in
# /usr/share/doc/netmagis/examples/upgrade/XX-YY/upgrade.sql.gz
#
# Conclusion :
# It is possible to determine the previous version and
# upgrade from any version to any version, step by step, just by
# following /usr/share/doc/netmagis/examples/upgrade/XX-YY/
# until we reach the version we target.
##################################################################

# set -x

# Halt on error
set -e

# check if we are upgrading from a 2.0 database
is_20_db="$(
runsql "
  -- ask postgres if there is a table dr_mbox in dns schema
  SELECT n.nspname, c.relname
  FROM pg_catalog.pg_class c
  LEFT JOIN pg_catalog.pg_namespace n
  ON n.oid = c.relnamespace
  WHERE
  c.relname = 'dr_mbox' AND n.nspname = 'dns'
"
)"

if test "$is_20_db"
then
  schemaversion=20
else

  # get schemaversion.
  schemaversion="$(
    runsql "
      SELECT value
      FROM global.config
      WHERE key = 'schemaversion'
    " 2>/dev/null || :
  )"

  if test '' = "$schemaversion"
  then
    schemaversion=21
  fi
fi

while test $TARGET_VERSION != "$schemaversion"
do
  path=$( ls -d /usr/share/doc/netmagis/examples/upgrade/${schemaversion}-* 2>/dev/null || : )
  test -d "$path" ||
    fatal "No way to upgrade database from version $schemaversion"
  next=$path
  next=${next##*-}
  test -r "$path/upgrade.sql.gz" ||
    fatal "Can't upgrade from $schemaversion to $next : $path/upgrade.sql.gz unreadable"
  gzip -cd "$path"/upgrade.sql.gz | pipesql
  schemaversion=$next
done

: