command to clean up old log files

Question

I was trying to automate some auto cleaning of my Ubuntu System, with Cron Jobs

I tryed to simplify this:

sudo find /var/log -type f -name "*.1.gz" -delete
sudo find /var/log -type f -name "*.2.gz" -delete
sudo find /var/log -type f -name "*.3.gz" -delete
sudo find /var/log -type f -name "*.4.gz" -delete
,etc...

into one command like this below but is not working, probably because I don't know...

for i=[^0-9]; sudo find /var/log -type f -name "*.$i.gz"

I tried similar ones but didn't worked too... :

$i=[^0-9]; sudo find /var/log -type f -name "*.$i.gz"
i=[^0-9]; sudo find /var/log -type f -name "*.$i.gz"
i=[^0-9]+$; sudo find /var/log -type f -name "*.$i.gz"

I can't see any output with this last four ones... and someones produces errors...

So what is the correct command / syntax?
And any other ideas to keep my "mini" server clean?

Other question: If I run sudo find / -type f -name "*.7.gz"
will appear this one:
"/usr/share/doc/libruby1.9.1/NEWS-1.8.7.gz"

I can solve with this:

if I run: sudo find / -type f -name "*log.7.gz"
BUT I will probably skip those with *error.(0-9).gz extension and many others...

Any idea to clean old logs under / without find/remove like these ones: "/usr/share/doc/libruby1.9.1/NEWS-1.8.7.gz"

EDIT

in my /etc/logrotate.d are:

/var/log/apache2/*.log {
    weekly
    missingok
    rotate 52
    compress
    delaycompress
    notifempty
    create 640 root adm
    sharedscripts
    postrotate
                if /etc/init.d/apache2 status > /dev/null ; then \
                    /etc/init.d/apache2 reload > /dev/null; \
                fi;
    endscript
    prerotate
        if [ -d /etc/logrotate.d/httpd-prerotate ]; then \
            run-parts /etc/logrotate.d/httpd-prerotate; \
        fi; \
    endscript
}
/var/log/apport.log {
       daily
       rotate 7
       delaycompress
       compress
       notifempty
       missingok
}

/var/log/apt/term.log {
  rotate 12
  monthly
  compress
  missingok
  notifempty
}

/var/log/apt/history.log {
  rotate 12
  monthly
  compress
  missingok
  notifempty
}

/var/log/aptitude {
  rotate 6
  monthly
  compress
  missingok
  notifempty
}
/var/log/cups/*log {
    daily
    missingok
    rotate 7
    sharedscripts
    prerotate
        if [ -e /var/run/cups/cupsd.pid ]; then
            invoke-rc.d --quiet cups stop > /dev/null
            touch /var/run/cups/cupsd.stopped
        fi
    endscript
    postrotate
        if [ -e /var/run/cups/cupsd.stopped ]; then
            rm /var/run/cups/cupsd.stopped
            invoke-rc.d --quiet cups start > /dev/null
            sleep 10
        fi
    endscript
    compress
    notifempty
    create
}
/var/log/dpkg.log {
    monthly
    rotate 12
    compress
    delaycompress
    missingok
    notifempty
    create 644 root root
}
/var/log/alternatives.log {
    monthly
    rotate 12
    compress
    delaycompress
    missingok
    notifempty
    create 644 root root
}
# - I put everything in one block and added sharedscripts, so that mysql gets 
#   flush-logs'd only once.
#   Else the binary logs would automatically increase by n times every day.
/var/log/mysql.log /var/log/mysql/mysql.log /var/log/mysql/mysql-slow.log /var/log/mysql/error.log {
    daily
    rotate 7
    missingok
    create 640 mysql adm
    compress
    sharedscripts
    postrotate
        test -x /usr/bin/mysqladmin || exit 0
        # If this fails, check debian.conf! 
        MYADMIN="/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf"
        if [ -z "`$MYADMIN ping 2>/dev/null`" ]; then
          # Really no mysqld or rather a missing debian-sys-maint user?
          # If this occurs and is not a error please report a bug.
          #if ps cax | grep -q mysqld; then
          if killall -q -s0 -umysql mysqld; then
            exit 1
          fi 
        else
          $MYADMIN flush-logs
        fi
    endscript
}
/var/log/pm-suspend.log /var/log/pm-powersave.log {
       monthly
       rotate 4
       delaycompress
       compress
       notifempty
       missingok
}
/var/log/ppp-connect-errors {
    weekly
    rotate 4
    missingok
    notifempty
    compress
    nocreate
}

/var/log/syslog
{
    rotate 7
    daily
    missingok
    notifempty
    delaycompress
    compress
    postrotate
        reload rsyslog >/dev/null 2>&1 || true
    endscript
}

/var/log/mail.info
/var/log/mail.warn
/var/log/mail.err
/var/log/mail.log
/var/log/daemon.log
/var/log/kern.log
/var/log/auth.log
/var/log/user.log
/var/log/lpr.log
/var/log/cron.log
/var/log/debug
/var/log/messages
{
    rotate 4
    weekly
    missingok
    notifempty
    compress
    delaycompress
    sharedscripts
    postrotate
        reload rsyslog >/dev/null 2>&1 || true
    endscript
}
/var/log/speech-dispatcher/speech-dispatcher.log /var/log/speech-dispatcher/speech-dispatcher-protocol.log {
  daily
  compress
  missingok
  sharedscripts
  rotate 7
  postrotate
    /etc/init.d/speech-dispatcher reload >/dev/null
  endscript
}

/var/log/speech-dispatcher/debug-epos-generic /var/log/speech-dispatcher/debug-festival /var/log/speech-dispatcher/debug-flite {
  daily
  compress
  missingok
  sharedscripts
  rotate 2
  postrotate
    /etc/init.d/speech-dispatcher reload >/dev/null
  endscript
}
/var/log/ufw.log
{
    rotate 4
    weekly
    missingok
    notifempty
    compress
    delaycompress
    sharedscripts
    postrotate
        invoke-rc.d rsyslog reload >/dev/null 2>&1 || true
    endscript
}
/var/log/unattended-upgrades/unattended-upgrades.log 
/var/log/unattended-upgrades/unattended-upgrades-shutdown.log
{
  rotate 6
  monthly
  compress
  missingok
  notifempty
}
/var/log/upstart/*.log {
        daily
        missingok
        rotate 7
        compress
        notifempty
    nocreate
}
/var/log/vsftpd.log
{
    create 640 root adm

    # ftpd doesn't handle SIGHUP properly
    missingok
    notifempty
    rotate 4
    weekly
}

and in /etc/logrotate.conf:

# see "man logrotate" for details
# rotate log files weekly
weekly

# use the syslog group by default, since this is the owning group
# of /var/log/syslog.
su root syslog

# keep 4 weeks worth of backlogs
rotate 4

# create new (empty) log files after rotating old ones
create

# uncomment this if you want your log files compressed
#compress

# packages drop log rotation information into this directory
include /etc/logrotate.d

# no packages own wtmp, or btmp -- we'll rotate them here
/var/log/wtmp {
    missingok
    monthly
    create 0664 root utmp
    rotate 1
}

/var/log/btmp {
    missingok
    monthly
    create 0660 root utmp
    rotate 1
}

# system-specific logs may be configured here

Can I set up to 100k rotate 3 all logs per example? How? and how much logs will last at minimum with that configuration?

Solution

No need to use a for-loop here, you can just use find:

sudo find /var/log/ -type f -regex '.*\.[0-9]+\.gz$' -delete

However, as it was suggested, check the manual page of logrotate for ways to reduce the number of files.

Comments

[Stephen Kitt]

logrotate is designed to manage your logs for you; it's probably already installed on your system. Have a look at its documentation to reduce the number of log files it keeps... Reducing the value after rotate in /etc/logrotate.conf should be sufficient.