Tag Archives: Linux

My Play Framework logrotate configuration

Here is another script I need to keep handy for the future. My logrotate script for Play Framework applications. The important thing here is the parameter “copytruncate”. I tried many times without it and the result was always the same: after the logrotate was done no more logging was made by the application. “copytruncate” solved this

/opt/myapp/logs/*.log {
  missingok
  notifempty
  size 50M
  copytruncate
  create 0644 root root
  rotate 9999
}

How to run logrotate manually:

logrotate --force /etc/logrotate.d/myapp

Tested on Ubuntu 14.04 and Play Framework 2.3

A small MySQL backup script using mysqldump and creates one file per database

This is the script I use for all my Amazon RDS instances local backups (called from an EC2). It gives me one db backup file for every database in the RDS instance, and at the end it makes sure that I don’t have any files older then 30 days. I put it here now so I don’t loose it again 🙂

#!/bin/bash

DATE=$(date +"%Y%m%d_%H%M")
DATABASES=`mysql -hsomedbname-someregion.rds.amazonaws.com -udbadmin -pmypassword -e "show databases;"`

for db in $DATABASES; do
        echo $db
        mysqldump --databases $db --single-transaction -hsomedbname-someregion.rds.amazonaws.com -udbadmin -pmypassword | gzip > /opt/backup/mysql.backup.$db.$DATE.sql.gz
done
find /opt/backup/* -mtime +30 -exec rm {} \;

I set this on a two hour cron to make sure that I have fresh backups of my production databases

0 */2 * * * /opt/scripts/mysql_db_backup.sh > /var/log/mysql_db_backup.log

Find all hosts on network with Nmap

To find all pingable hosts on the newtwork you are currently on first find your own ip. In Linux/OSX you can run the command ifconfig (windows uses the ‘ipconfig’ command):

malen@LKGADEFB8:~$ sudo ifconfig
eth0      Link encap:Ethernet  HWaddr 00:1d:7e:ad:ef:b8  
          inet addr:192.168.0.77  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::21d:7eff:fead:efb8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:23647854 errors:0 dropped:83 overruns:0 frame:0
          TX packets:31522391 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:320343317 (305.5 MiB)  TX bytes:3340057852 (3.1 GiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1736 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1736 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:159128 (155.3 KiB)  TX bytes:159128 (155.3 KiB)

You here see your IP at ‘inet addr’ on eth0: 192.168.0.77. To see if there are any other hosts on the 192.168.0.x net use:

nmap -v -sP 192.168.0.1/24

This will ping all hosts on 192.168.0.x and show your result in a list

Host 192.168.0.1 appears to be down.
Host 192.168.0.2 appears to be down.
Host 192.168.0.3 appears to be down.
Host 192.168.0.4 appears to be down.
Host 192.168.0.5 appears to be down.
...
Host Slug (192.168.0.77) appears to be up.
...
Host 192.168.0.250 appears to be down.
Host 192.168.0.251 appears to be down.
Host 192.168.0.252 appears to be down.
Host 192.168.0.253 appears to be down.
Host 192.168.0.254 appears to be down.
Host 192.168.0.255 appears to be down.

Tested on OSX 10.7.4 and Debian Lenny