apt/debian/apt.cron.daily

#!/bin/sh
#set -e
#
# This file understands the following apt configuration variables:
# Values here are the default.
# Create /etc/apt/apt.conf.d/02periodic file to set your preference.
#
#  Dir "/";
#  - RootDir for all configuration files
#
#  Dir::Cache "var/apt/cache/";
#  - Set apt package cache directory
#
#  Dir::Cache::Archive "archives/";
#  - Set package archive directory
#
#  APT::Periodic::BackupArchiveInterval "0";
#  - Backup after n-days if archive contents changed.(0=disable)
#
#  APT::Periodic::BackupLevel "3";
#  - Backup level.(0=disable), 1 is invalid.
#
#  Dir::Cache::Backup "backup/";
#  - Set periodic package backup directory
#
#  APT::Archives::MaxAge "0"; (old, deprecated)
#  APT::Periodic::MaxAge "0"; (new)
#  - Set maximum allowed age of a cache package file. If a cache 
#    package file is older it is deleted (0=disable)
#
#  APT::Archives::MinAge "2"; (old, deprecated)
#  APT::Periodic::MinAge "2"; (new)
#  - Set minimum age of a package file. If a file is younger it
#    will not be deleted (0=disable). Usefull to prevent races 
#    and to keep backups of the packages for emergency.
#
#  APT::Archives::MaxSize "0"; (old, deprecated)
#  APT::Periodic::MaxSize "0"; (new)
#  - Set maximum size of the cache in MB (0=disable). If the cache
#    is bigger, cached package files are deleted until the size
#    requirement is met (the biggest packages will be deleted 
#    first).
#
#  APT::Periodic::Update-Package-Lists "0";
#  - Do "apt-get update" automatically every n-days (0=disable)
#    
#  APT::Periodic::Download-Upgradeable-Packages "0";
#  - Do "apt-get upgrade --download-only" every n-days (0=disable)
# 
#  APT::Periodic::Unattended-Upgrade "0";
#  - Run the "unattended-upgrade" security upgrade script 
#    every n-days (0=disabled)
#    Requires the package "unattended-upgrades" and will write
#    a log in /var/log/unattended-upgrades
# 
#  APT::Periodic::AutocleanInterval "0";
#  - Do "apt-get autoclean" every n-days (0=disable)
#
#  APT::Periodic::Verbose "0";
#  - Send report mail to root
#      0:  no report             (or null string)
#      1:  progress report       (actually any string)
#      2:  + command outputs     (remove -qq, remove 2>/dev/null, add -d)
#      3:  + trace on            

check_stamp()
{
    stamp="$1"
    interval="$2"

    if [ $interval -eq 0 ]; then
	debug_echo "check_stamp: interval=0."
	# treat as no time has passed
        return 1
    fi

    if [ ! -f $stamp ]; then
    	update_stamp $stamp
	debug_echo "check_stamp: missing time stamp file: $stamp."
	# treat as enough time has passed
        return 0
    fi

    # compare midnight today to midnight the day the stamp was updated
    stamp=$(date -r $stamp '+%s')
    delta=$(($now-$stamp))

    # intervall is in days, convert to sec.
    interval=$(($interval*60*60*24))
    debug_echo "check_stamp: interval=$interval, now=$now, stamp=$stamp, delta=$delta (sec)"

    if [ $delta -ge $interval ]; then
        return 0
    fi

    return 1
}

update_stamp()
{
    stamp="$1"
    touch $stamp
}

debug_echo()
{
    # Display message if $VERBOSE >= 1
    if [ "$VERBOSE" -ge 1 ]; then
	echo $1 1>&2
    fi
}

# check apt-config exstance
if ! which apt-config >/dev/null ; then
	exit 0
fi

# Set VERBOSE mode from  apt-config (or inherit from environment)
eval $(apt-config shell VERBOSE APT::Periodic::Verbose)
if [ -z "$VERBOSE" ]; then
    VERBOSE="0"
fi
if [ "$VERBOSE" -le 2 ]; then
    # quiet for 0,1,2
    XSTDOUT=">/dev/null"
    XSTDERR="2>/dev/null"
    XAPTOPT="-qq"
    XUUPOPT=""
else
    XSTDOUT=""
    XSTDERR=""
    XAPTOPT=""
    XUUPOPT="-d"
fi
if [ "$VERBOSE" -ge 3 ]; then
    # trace output
    set -x
fi

# laptop check, on_ac_power returns:
#       0 (true)    System is on main power
#       1 (false)   System is not on main power
#       255 (false) Power status could not be determined
# Desktop systems always return 255 it seems
if which on_ac_power >/dev/null; then
    on_ac_power
    POWER=$?
    if [ $POWER -eq 1 ]; then
	debug_echo "exit: system on main power."
	exit 0
    elif [ $POWER -ne 0 ]; then
	debug_echo "exit: power status ($POWER) undetermined."
	exit 0
    fi
    debug_echo "system is on main power."
fi

# check if we can lock the cache and if the cache is clean
if which apt-get >/dev/null && ! eval apt-get check $XAPTOPT $XSTDERR ; then
    debug_echo "error encountered in cron job with \"apt-get check\"."
    exit 0
fi
# No need to check for apt-get below

# Global current time in seconds since 1970-01-01 00:00:00 UTC
now=$(date +%s)

# Set default values and normalize
Dir="/"
eval $(apt-config shell Dir Dir)
Dir=${Dir%/}

CacheDir="var/cache/apt/"
eval $(apt-config shell CacheDir Dir::Cache)
CacheDir=${CacheDir%/}
if [ -z "$CacheDir" ]; then
    debug_echo "practically empty Dir::Cache, exiting"
    exit 0
fi

CacheArchive="archives/"
eval $(apt-config shell CacheArchive Dir::Cache::Archives)
CacheArchive=${CacheArchive%/}
if [ -z "$CacheArchive" ]; then
    debug_echo "practically empty Dir::Cache::archives, exiting"
    exit 0
fi

BackupArchiveInterval=0
eval $(apt-config shell BackupArchiveInterval APT::Periodic::BackupArchiveInterval)

BackupLevel=3
eval $(apt-config shell BackupLevel APT::Periodic::BackupLevel)
if [ $BackupLevel -le 1 ]; then BackupLevel=2 ; fi

CacheBackup="backup/"
eval $(apt-config shell CacheBackup Dir::Cache::Backup)
CacheBackup=${CacheBackup%/}
if [ -z "$CacheBackup" ]; then
    echo "practically empty Dir::Cache::Backup, exiting" 1>&2
    exit 0
fi

# Support old Archive for compatibility.
# Document only Periodic for all controling parameters of this script.
MaxAge=0
eval $(apt-config shell MaxAge APT::Archives::MaxAge)
eval $(apt-config shell MaxAge APT::Periodic::MaxAge)

MinAge=2
eval $(apt-config shell MinAge APT::Archives::MinAge)
eval $(apt-config shell MinAge APT::Periodic::MinAge)

MaxSize=0
eval $(apt-config shell MaxSize APT::Archives::MaxSize)
eval $(apt-config shell MaxSize APT::Periodic::MaxSize)

UpdateInterval=0
eval $(apt-config shell UpdateInterval APT::Periodic::Update-Package-Lists)

DownloadUpgradeableInterval=0
eval $(apt-config shell DownloadUpgradeableInterval APT::Periodic::Download-Upgradeable-Packages)

UnattendedUpgradeInterval=0
eval $(apt-config shell UnattendedUpgradeInterval APT::Periodic::Unattended-Upgrade)

AutocleanInterval=0
eval $(apt-config shell AutocleanInterval APT::Periodic::AutocleanInterval)

Cache="${Dir}/${CacheDir}/${CacheArchive}/"
Back="${Dir}/${CacheDir}/${CacheBackup}/"
BackX="${Back}${CacheArchive}/"
for x in $(seq 0 1 $((${BackupLevel}-1))); do 
    eval "Back${x}=${Back}${x}/"
done

# check if we actually have to do anything
if [ $UpdateInterval -eq 0 ] &&
   [ $DownloadUpgradeableInterval -eq 0 ] &&
   [ $UnattendedUpgradeInterval -eq 0 ] &&
   [ $BackupArchiveInterval -eq 0 ] &&
   [ $AutocleanInterval -eq 0 ]; then
    exit 0
fi


# backup after n-days if archive contents changed.
# (This uses hardlink to save disk space)
BACKUP_ARCHIVE_STAMP=/var/lib/apt/periodic/backup-archive-stamp
if check_stamp $BACKUP_ARCHIVE_STAMP $BackupArchiveInterval; then
    if [ $({(cd $Cache 2>/dev/null; find . -name "*.deb"); (cd $Back0 2>/dev/null;find . -name "*.deb") ;}| sort|uniq -u|wc -l) -ne 0 ]; then
	mkdir -p $Back
	rm -rf $Back$((${BackupLevel}-1))
	for y in $(seq $((${BackupLevel}-1)) -1 1); do 
	    eval BackY=${Back}$y
	    eval BackZ=${Back}$(($y-1))
	    if [ -e $BackZ ]; then mv -f $BackZ $BackY ; fi
	done
	cp -la $Cache $Back ; mv -f $BackX $Back0
	update_stamp $BACKUP_ARCHIVE_STAMP
	debug_echo "backup with hardlinks. (success)"
    else

	debug_echo "skip backup since same content."
    fi
else
	debug_echo "skip backup since too new."
fi

# package archive contnts removal by package age
if [ $MaxAge -ne 0 ] && [ $MinAge -ne 0 ]; then
    find $Cache -name "*.deb"  \( -mtime +$MaxAge -and -ctime +$MaxAge \) -and -not \( -mtime -$MinAge -or -ctime -$MinAge \) -print0 | xargs -r -0 rm -f
    debug_echo "aged: ctime <$MaxAge and mtime <$MaxAge and ctime>$MinAge and mtime>$MinAge"
elif [ $MaxAge -ne 0 ]; then
    find $Cache -name "*.deb"  -ctime +$MaxAge -and -mtime +$MaxAge -print0 | xargs -r -0 rm -f
    debug_echo "aged: ctime <$MaxAge and mtime <$MaxAge only"
else
    debug_echo "skip aging since MaxAge is 0"
fi
    
# package archive contnts removal down to $MaxSize
if [ $MaxSize -ne 0 ]; then

    MinAgeSec=$(($MinAge*24*60*60))

    # reverse-sort by mtime
    for file in $(ls -rt $Cache/*.deb 2>/dev/null); do 
	du=$(du -m -s $Cache)
	size=${du%%/*}
	# check if the cache is small enough
	if [ $size -lt $MaxSize ]; then
	    debug_echo "end remove by archive size:  size=$size < $MaxSize"
	    break
	fi

	# check for MinAge in second of the file
	if [ $MinAgeSec -ne 0 ]; then 
	    # check both ctime and mtime 
	    mtime=$(stat -c %Y $file)
	    ctime=$(stat -c %Z $file)
	    if [ $mtime -gt $ctime ]; then
		delta=$(($now-$mtime))
	    else
		delta=$(($now-$ctime))
	    fi
	    if [ $delta -le $MinAgeSec ]; then
		debug_echo "skip remove by archive size:  $file, delta=$delta < $MinAgeSec"
	    else
		# delete oldest file
		debug_echo "remove by archive size: $file, delta=$delta >= $MinAgeSec (sec), size=$size >= $MaxSize"
		rm -f $file
	    fi
	fi

    done
fi

# update package lists
UPDATE_STAMP=/var/lib/apt/periodic/update-stamp
if check_stamp $UPDATE_STAMP $UpdateInterval; then
    if eval apt-get $XAPTOPT -y update $XSTDERR; then
	debug_echo "download updated metadata (success)."
	if which dbus-send >/dev/null && pidof dbus-daemon >/dev/null; then
	    if dbus-send --system / app.apt.dbus.updated boolean:true ; then
		debug_echo "send dbus signal (success)"
	    else
		debug_echo "send dbus signal (error)"
	    fi
	else
	    debug_echo "dbus signal not send (command not available)"
	fi
	update_stamp $UPDATE_STAMP
	# download all upgradeable packages if it is requested
	DOWNLOAD_UPGRADEABLE_STAMP=/var/lib/apt/periodic/download-upgradeable-stamp
	if check_stamp $DOWNLOAD_UPGRADEABLE_STAMP $DownloadUpgradeableInterval; then
	    if eval apt-get $XAPTOPT -y -d dist-upgrade $XSTDERR; then
		update_stamp $DOWNLOAD_UPGRADEABLE_STAMP
		debug_echo "download upgradable (success)."
		# auto upgrade all upgradeable packages
		UPGRADE_STAMP=/var/lib/apt/periodic/upgrade-stamp
		if which unattended-upgrade >/dev/null && check_stamp $UPGRADE_STAMP $UnattendedUpgradeInterval; then
		    if unattended-upgrade $XUUPOPT; then
			update_stamp $UPGRADE_STAMP
			debug_echo "unattended-upgrade (success)."
		    else
			debug_echo "unattended-upgrade (error)."
		    fi
		else
		    debug_echo "unattended-upgrade (not run)."
		fi
	    else
		debug_echo "download upgradable (error)."
	    fi
	else
	    debug_echo "download upgradable (not run)."
	fi
    else
	debug_echo "download updated metadata (error)."
    fi
else
    debug_echo "download updated metadata (not run)."
fi

# autoclean package archive
AUTOCLEAN_STAMP=/var/lib/apt/periodic/autoclean-stamp
if check_stamp $AUTOCLEAN_STAMP $AutocleanInterval; then
    if apt-get $XAPTOPT -y autoclean $XSTDERR; then
	debug_echo "autoclean (success)."
	update_stamp $AUTOCLEAN_STAMP
    else
	debug_echo "autoclean (error)."
    fi
else
    debug_echo "autoclean (not run)."
fi

#
#     vim: set sts=4 ai :
#