Category: Uncategorized

Gather metatdata on AWS from within EC2 instance.

Posted on by admin

So I need to get information about a particular set of machines in the cloud (AWS).

EC2_INSTANCE_ID="`wget -q -O - http://instance-data/latest/meta-data/instance-id || die \"wget instance-id has failed: $?\"`"
test -n "$EC2_INSTANCE_ID" || die 'cannot obtain instance-id'
EC2_AVAIL_ZONE="`wget -q -O - http://instance-data/latest/meta-data/placement/availability-zone || die \"wget availability-zone has failed: $?\"`"
test -n "$EC2_AVAIL_ZONE" || die 'cannot obtain availability-zone'
EC2_REGION="`echo \"$EC2_AVAIL_ZONE\" | sed -e 's:\([0-9][0-9]*\)[a-z]*\$:\\1:'`"

 

nJoy 😉

 

 

package.json sample

Posted on by admin

This is the basic structure for a node.js package file

{
"name": "Express-Basic",
"description": "Demonstrating Express",
"version": "0.0.1",
"private": true,
"dependencies": {
"express": "3.x"
}
}

nJoy 😉

Kernel: e1000e 0000:02:00.0: eth0: Error reading PHY register

Posted on by admin

In recent CentOS version 6.3 is an unresolved bug, which causes the network card to freeze the server.

Following message appears in /var/log/messages

kernel

To work around the problem you will need to turn off Active-State Power Management (ASPM)
(Feature that saves power in the Peripheral Component Interconnect Express (PCI Express or PCIe) subsystem by setting a lower power state for PCIe links when the devices to which they connect are not in use)

For GRUB bootloader edit the following file: /boot/grub/grub.conf and append pcie_aspm=off to the end of kernel boot line.

For example:

kernel /vmlinuz-2.6.32-279.el6.x86_64 ro root=UUID=81e9e0a2-0a51-4d75-955d-909aaf848192 rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_NO_DM rd_MD_UUID=c6855f45:016a63bb:2d79bfb2:07371ed8 rd_NO_LVM rd_MD_UUID=5d5a434e:6c20cfcd:51340c3f:29c29151 pcie_aspm=off

To verify the change, reboot the server and run the following command:

dmesg | grep PCIe
PCIe ASPM is disabled

If your output is different, the change in grub.conf did not take an effect.

Set timezone Centos

Posted on by admin

vim /etc/sysconfig/clock

ZONE=”Europe/London”

 

ln -sf /usr/share/zoneinfo/Europe/London /etc/localtime

done..

nJoy 😉

 

Sending Elasticsearch to a syslog server

Posted on by admin

yum install rsyslog -y

Add the following to rsyslog.conf on the client system

############

$ModLoad imfile
$InputFileName /var/log/elasticsearch/elasticsearch.log
$InputFileTag elasticsearch
$InputFileStateFile stat-elasticsearch
$InputFileSeverity Info
$InputFileFacility daemon
$InputRunFileMonitor
#local3.* hostname:<portnumber>

daemon.* @192.168.1.66:514


############

 

Also if you want all logs to go through to syslog server:

 

*.* @192.168.1.66

 

at the end of the file.

Issue a :

service rsyslog restart

and watch the logs flow in.

 

nJoy 😉