apt-mirror fix to download installer files

Here are the changes I had to make to be able to download complete Ubuntu repository with X86_64 installer (netboot) directory contents. The apt-mirror was also failing for in18n directory as some files with extensions xz needed to be downloaded - that is fixed as well. Pay attention to less than symbol "<"

root@dhcp2064-29:~# diff /usr/bin/apt-mirror /usr/bin/apt-mirror.ori
> 
423,430d451
<             add_url_to_download( $url . $_ . "/cnf/Commands-" . $arch . ".xz" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/" . "boot.img.gz" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/" . "ldlinux.c32" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/" . "mini.iso" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/" . "netboot.tar.gz" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/" . "pxelinux.0" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/ubuntu-installer/amd64/" . "initrd.gz" );            
<             add_url_to_download( $url . $_ . "/installer-amd64/current/legacy-images/netboot/ubuntu-installer/amd64/" . "linux" );            
466,467c487
<     #$uri =~ s/^([^@]+)?@?// if $uri =~ /@/;
<     $uri =~ s/^([^@]+)?@?// if (split '/',$uri)[0] =~ /@/;
---
>     $uri =~ s/^([^@]+)?@?// if $uri =~ /@/;
503c523
<                     if ( $filename =~ m{^$component/i18n/Translation-[^./]*\.(bz2|xz)$} )
---
>                     if ( $filename =~ m{^$component/i18n/Translation-[^./]*\.bz2$} )
1046d1065
< 

AWK with if-else loop example

Bash script with AWK example - in this example, if the line contains one type of keywords, I wanted to add something in the end of same line and if the line contained something else, I wanted to add some other text.

cat /tmp/file1 |  \
 awk '{ 
  if ($0~"RHEL" || $0~"rhel" || $0~"CENT" || $0~"cent") 
            print $0 " --os-family \"Redhat\""
  if ($0~"Ubuntu" || $0~"UBUN" || $0~"ubun")
            print $0 " --os-family \"Debian\""
 };' > /tmp/file2

AWS EC2 Instance (advance section script) with webserver and availability zone info

The use of this script requires basic knowledge of AWS and shell scripting. This is the script I normally use when I want to test something in my personal account and let the instance be powered off after 2 hours.

This script will bring up EC2 instance with following :

* updated packages,
* HTTPD service installed and started,
* Also run a job at startup to Poweroff instance after 2 hours (refer 7200)

(Note: Poweroff is kept only for those who need instance only for practicing and/or limited time and to save costs. In case of production use, comment out poweroff statement)

#!/bin/bash
yum update -y
yum install httpd24 -y
service httpd start
chkconfig httpd on
echo "Hello, this is a test instance from `curl http://169.254.169.254/latest/meta-data/placement/availability-zone`" > /var/www/html/index.html

echo "# This will bring up instance only for below mentioned seconds" >> /etc/rc.local
echo "(sleep 7200; poweroff) &" >> /etc/rc.local

Kickstart troubleshooting

This is to see if a server which need to be kickstarted is able to get initial files from TFTP server (which runs on port 69).

[root@kickstarter pxelinux.cfg]# tcpdump -i eth0 port 69
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
11:30:19.077306 IP srv-9000.ah-esp-encap > kickstarter.domain.com.tftp:  41 RRQ "linux-install/pxelinux.0" octet tsize 0
11:30:19.106252 IP srv-9000.acp-port > kickstarter.domain.com.tftp:  46 RRQ "linux-install/pxelinux.0" octet blksize 1456
11:30:19.183548 IP srv-9000.40769 > kickstarter.domain.com.tftp:  77 RRQ "linux-install/pxelinux.cfg/01-c4-34-6b-b9-16-70" octet tsize 0 blksize 1440
11:30:19.213799 IP srv-9000.40770 > kickstarter.domain.com.tftp:  65 RRQ "linux-install/pxelinux.cfg/0A4461FA" octet tsize 0 blksize 1440
11:30:19.242361 IP srv-9000.40771 > kickstarter.domain.com.tftp:  63 RRQ "linux-install/rhel-as-7u1/vmlinuz" octet tsize 0 blksize 1440
11:30:35.973742 IP srv-9000.40772 > kickstarter.domain.com.tftp:  66 RRQ "linux-install/rhel-as-7u1/initrd.img" octet tsize 0 blksize 1440
^C
6 packets captured
38 packets received by filter
1 packets dropped by kernel

Annoying GUI Pop-up in VNC and how to disable it?

# ls -l /etc/xdg/autostart/gpk-update-icon.desktop

-rw-r--r-- 1 root root 7115 Feb 16 16:04 /etc/xdg/autostart/gpk-update-icon.desktop

Append below line in above mentioned file:

X-GNOME-Autostart-enabled=false

Once done, restart server and the pop-up shown above should be gone.