foswiki-upgrade-check

#!/bin/bash
set -a
USAGE='foswiki-upgrade-check [options] install_dir old_release new_release
This allows you to check what a foswiki upgrade would do, and perform it
with interactive merging. Arguments are:
  - install_dir your foswiki installation directory
  - old_release a directory containing the distributed release for it
  - new_release a directory containing the distributed new version
e.g:
foswiki-upgrade-check /www/fw /tmp/Foswiki-1.0.4 /tmp/Foswiki-1.0.5

By default it just list the files that conflicts and would need a merge.
This is useful, as it allows you to make a list of these files for later use
by -mfd or -nom. For instance, if you have a production foswiki on a distant
server that you can copy locally on your dev machine, you can:
  foswiki-upgrade-check on prod, save output in a file V
  foswiki-upgrade-check -y on a local copy on dev
  make a tar on local of files listed in V, upload to prod
  foswiki-upgrade-check -y -nom on prod, then untar your tar in prod

Options:
  -v      verbose: lists all operations that will be done
  -a      list all files that would be modified, not just the to merge ones.
  -s      do not merge, but show the diffs for all conflicts (use kdiff3)
  -y      yes, really "do it" performs the copy & merge
		  you must have write permission to the install_dir files.
		  Please make a BACKUP before!!!
		  If you do not want to make a full backup, you can backup the files
		  listed with the -a option that will be changed by the upgrade.
  -r      remove any files missing from the new release. (optional)
  -l      list all files of the installation that will be probed for upgrade
  -kd3    use kdiff3 to perform interactive merges (default)
  -xxd    use xxdiff to perform interactive merges
  -tkd    use tkdiff to perform interactive merges
  -mld    use meld to perform interactive merges
  -mfd DIR do not merge interactively, but instead in case of conflict take
		  file from DIR. Useful if DIR is a copy of your prod instance you
		  upgraded previously to test things and do not want to repeat manual
		  process and copy what you did there
  -nom    no merge, for all conflicts keep your files

PS: do not forget to fix files permissions after this, for instance by a
chown -R apache:apache ., chown -R www-data:www-data ., chmod -R a+rwX .
depending on your installation

PS: the "new_release" dir can also be the distributed "upgrade" package, but
it is advised to use the full release for the new version as otherwise small
discrepencies may appear on susequent upgrades

To upgrade a server with no graphical environment (remote), do:
  * run foswiki-upgrade-check on the server to list the conflicting files.
	take note of them for instance by a: (I O N are the installation, old and
	new dirs respectively)
	foswiki-upgrade-check $I $O $N >/tmp/fwu.list
	Do a backup via:
	cd $I; tar cfz /tmp/wiki-backup.tgz $(foswiki-upgrade-check -a $I $O $N)
  * copy the server install on your local workstation, by
	rsync -aHSx --delete --force SERVER:SRC/ DEST/
	If your installation is big, you can copy only the useful files for this
	upgrade by copying and untarring /tmp/fwi.tgz made on the server by:
	tar cfz /tmp/fwi.tgz $(foswiki-upgrade-check -l $I $O $N)
  * do the "foswiki-upgrade-check -y" locally (in DEST/) with your graphical
	merge tool
  * either re-upload your upgraded local copy to another place on the server
	(lets say /tmp/fwu ), or better just the resolved conflicts:
	rsync  -aHSx --delete --force -R `cat /tmp/fwu.list`  SERVER:/tmp/fwu/
	if you copied /tmp/fwu.list from the server to your workstation
  * on the server, perform the automatic merge with
	foswiki-upgrade-check -y -mfd /tmp/fwu $I $O $N

v1.0 2009-04-26 published on http://foswiki.org/Support/HowDoIUpgradeSafelyACustomizedFoswikiInstallation
v1.1 2009-08-18 -nom was not working
v1.2 2009-09-22 -s option, kdiff3 merge is now automatic if no conflicts
				detects case where file is new but different
				avoid merging binary files, just copy over.
v1.3 2010-02-26 dir arguments can now be relative
v1.4 2010-03-28 -a and -l options to help backuping
v1.5 2010-09-23 -f option
v1.6 2011-01-07 -r option (remove missing files).  Also prompt for optional merge.
v1.7 2011-02-16 Use jot if seq command does not exist (FreeBSD)
V1.8 2011-02-19 exclude commonly tailored files,  Better handle files missing from old release
'

merge=merge_kdiff3
doit=false
dolist=false
listall=false
verbose=false
remove=false
mfd=
showdiff=
seqcmd=true
excluded=( WebHome.txt WebPreferences.txt WebStatistics.txt WebNotify.txt SitePreferences.txt AdminGroup.txt TrashAttachment.txt )

doseq () { if $seqcmd; then seq $@;  else jot - $@; fi; }

function elementExists()
{
    file=${1##*/}

    if [ -z "$file" ]
    then
        return
    fi

    for exfile in ${excluded[@]}
    do
        if [ $exfile == $file ]
        then
            return 0
        fi
    done

    return 1
}


# Determine if the seq command is useful, otherwise we use jot
if command -v seq &>/dev/null
    then
        seqcmd=true
    else
        seqcmd=false
fi


# Options processing
while test "_${1#-}" != "_$1" -a "_${1//-/}" != "_";do case "$1" in
   -kd3) merge=merge_kdiff3;;
   -tkd) merge=merge_tkdiff;;
   -xxd) merge=merge_xxdiff;;
   -mld) merge=merge_meld;;
   -mfd) merge=merge_mfd; mfd=$2;shift;;
   -nom) merge=merge_none;;
   -s) showdiff=show_kdiff3;;
   -a) dolist=true;;
   -l) listall=true;;
   -y) doit=true;;
   -v) verbose=true;;
   -r) remove=true;;
   *) echo "$USAGE"; exit 1;
esac;shift; done; if test "_$1" = "_--";then shift; fi
if test $# != 3; then echo ERROR: 3 arguments needed; echo "$USAGE"; exit 1; fi
for d in "$@" $mfd; do
    if test ! -e $d/lib/Foswiki.pm; then
       echo ERROR: "$d" is not a foswiki directory; exit 1
    fi
done

I="$1"; O="$2"; U="$3"
case "$I" in /*) : ;; *) I="$PWD/$I";; esac
case "$O" in /*) : ;; *) O="$PWD/$O";; esac
case "$U" in /*) : ;; *) U="$PWD/$U";; esac

V () { if $verbose; then echo "$@"; fi; }
doit () { if $doit; then "$@"; fi; }
dolist () { if ! $doit; then if $dolist; then echo $1; fi; fi; }


if $listall; then
cd $I; for d in "$O" "$U";do ( cd $d; find * -type f );done|sort|uniq \
| while read f; do if test -e "$f"; then echo "$f";fi;done
exit 0
fi

# merge args are is the file, merge into installation
merge_kdiff3 () { kdiff3 -m --auto $orig $I/$1 $U/$1 -o $I/$1; }
show_kdiff3 () { kdiff3 $orig $I/$1 $U/$1; }
merge_tkdiff () { tkdiff -a $orig -o $I/$1 $I/$1 $U/$1; }
merge_xxdiff () { xxdiff --show-merged-pane -O -m -M $I/$1 $I/$1 $orig $U/$1; }
merge_meld   () { meld $orig $I/$1 $U/$1; }
merge_mfd    () { cp $mfd/$1 $I/$1; }
merge_none   () { :; }

is_binary () {
case "$1" in
*.gif|*.GIF|*.png|*.PNG|*.jpg|*.JPG|*.gz|*.GZ) return 0;;
*) return 1;;
esac
}

# I is the installed wiki,
# O the old distribution used to install it,
# U the new upgrade or full distrib
cd $U

file_list=( $(find * -type f) )

for element in $(doseq 0 $((${#file_list[@]} - 1))); do
    i=${file_list[$element]}
    if elementExists $i; then
        echo "SKIPPING $U/$i - file is not normally updated"
        continue
    fi
    #echo "Processing file $i "
    if test -e $I/$i; then                                  # File exists in installed Wiki
        if ! cmp -s $i $I/$i; then                          # Installed not same as New
            if cmp -s $O/$i $I/$i; then                     # Old same as installed
               V $i LOCALLY_SAME, DIST_CHANGED, COPY
               doit cp $U/$i $I/$i
               dolist $i
            elif cmp -s $i $O/$i; then
               V $i LOCALLY_CHANGED, DIST_SAME. KEEP
            else                                           # Old file has changed
                if test ! -e $O/$i; then
                    V $i NEW FILE, BUT DIFFERENT IN LOCAL AND UPGRADE
                    echo "WARNING: New file $U/$i conflicts with existing file $I/$i "
                    orig=/dev/null
                else
                    V $i CONFLICT, MERGE
                    orig=$O/$i
                fi
                if $doit; then
                    if is_binary "$i"; then
                        echo "WARNING: copied $U/$i over your $I/$i . Revert if wrong"
                        doit cp $U/$i $I/$i
                        dolist $i
                    else
                        echo "How do you want to handle conflict: $U/$i ?"
                        select ans in "Merge files" "Keep original" "Use new file"
                        do
                            echo "Answer $ans "
                            case $ans in
                               "Merge files" ) echo "merge"; doit $merge $i; break;;
                               "Keep original" ) echo "keeping original"; break;;
                               "Use new file" ) echo "using new"; doit cp $U/$i $I/$i; break;;
                            esac
                        done
                    fi
                elif test -n "$showdiff"; then
                    if is_binary "$i"; then ls -l $orig $I/$1 $U/$1
                    else $showdiff $i
                    fi
                else echo $i
                fi
            fi
        else
        V $i SAME, IGNORE
        fi
    else
        V $i NEW FILE, COPY
        if $doit; then
            dir=$I/$i; dir=${dir%/*}
            if test ! -d $dir; then mkdir -p $dir; fi
            cp $U/$i $I/$i
        fi
    fi
done

if $remove; then
    cd $O

    old_list=( $(find * -type f) )

    for element in $(doseq 0 $((${#old_list[@]} - 1))); do
        i=${old_list[$element]}
        if test -e $I/$i; then
            if test ! -e $U/$i; then
                if ! cmp -s $i $I/$i; then
                   V $i LOCALLY_MODIFIED, DIST_REMOVED, REMOVE
                   if $doit; then
                       echo "Warning, file to be removed has been locally modified: $U/$i ?"
                       echo "How do you want to handle conflict: ?"
                       select ans in "Keep original" "Remove anyway"
                       do
                           echo "Answer $ans "
                           case $ans in
                              "Keep original" ) echo "keeping original"; break;;
                              "Remove anyway" ) echo "removing anyway"; doit rm -v $I/$i; break;;
                           esac
                       done
                   fi
                else
                   V $i LOCALLY_PRESENT, DIST_REMOVED, REMOVE
                   doit rm -v $I/$i
                   if ! $doit; then
                      echo "$i (remove)"
                   fi
                fi
            fi
        fi
    done
fi