Thursday, March 31, 2011

Removing old keys in your known_hosts file

If you happen to have changed server IP address and while at it you get this message doing a remote connnection:

ssh ants@192.168.1.1
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
eb:e8:de:47:00:77:2c:14:28:20:db:18:4c:9f:69:02.
Please contact your system administrator.
Add correct host key in /home/ants/.ssh/known_hosts to get rid of this message.
Offending key in /home/ants/.ssh/known_hosts:13
RSA host key for 192.168.1.1 has changed and you have requested strict checking.
Host key verification failed.

You will have to remove the entry by editing your known_hosts file.  Remove the old entry, in this case its on line "13" save the file and try connecting again, accept the new one when prompted.

Done.

Wednesday, March 30, 2011

SMS triggered service executions on Unix/Linux Systems,

There isn't enough material out there on the net that teaches systems administrators a thing or two about how to integrate your SMS monitoring to a complete real time system that allows you to execute commands via SMS.

In this post we will do just that.  The requirement is that you have an SMS server running and functional; plenty of time to brush up on your proof of concept skills.  It may not be the complete solution to what you have in mind but for me it works fine.  The goal is simply to respond to issues you deal on a day-to-day basis, albeit real-time response whenever a problem arises.

Planning 

Map out the logical flow behind your project.  We all know that SMS messages are triggered events, it could be automatic events or human response events.  A working SMS server will have both; by the time you receive a message coming from your monitoring system suggest that an automatic event has been triggered which based on the given configuration you made; sent out the notification informing you that such an event has taken place.  Now, often if a computer is within reach our first reflex-response is to login work on the issue.  This is the reality for the first given days, weeks and months.  Apparently, that ceases when you encounter too-many false positives. 


Working out a Real-time solution

To address this one-way communication between you and to those systems that you manage you have to be able to manage it directly via your mobile phone.  A cheap solution to a very urgent event which could mean alot to the company you manage.

.... to be continued ....

Tuesday, March 22, 2011

OpenKM: ERROR [MainDeployer] Could not create deployment: file:/opt/jboss-4.2.3.GA/server/default/conf/jboss-service.xml

If you happen to have a problem with this:  ERROR [MainDeployer] Could not create deployment: file:/opt/jboss-4.2.3.GA/server/default/conf/jboss-service.xml

This means that their is a problem with your host file.  Make sure that you have configured your hostname in line with your local ip address.