Reverse Dns check

172:rp young$ cat iptodns.rb 

#!/usr/bin/env ruby

require 'resolv'

def check

 if ARGV[0] == nil

   abort 'Please input ARGV[0]'

 end

end

check

def ipdcheck

 begin 

   puts Resolv.getname(ARGV[0])

 rescue

   puts "No hostname associated with #{ARGV[0]}"

 end

end

ipdcheck

Example)

172:rp young$ ruby iptodns.rb 202.131.30.12

No hostname associated with 202.131.30.12

172:rp young$ ruby iptodns.rb 127.0.0.1

localhost

172:rp young$ ruby iptodns.rb 192.0.34.166

34-166.lax.icann.org

172:rp young$ 

Simple ips to certain dns

172:rp young$ cat dns_ip.rb 

#!/usr/bin/env ruby

def check

 if ARGV[0] == nil

  abort 'please input ARGV[0]'

 end

end

check

require 'resolv'

def check_address

    Resolv.each_address(ARGV[0]) do |ip|

      puts ip

    end

end

check_address

172:rp young$ ruby dns_ip.rb naver.com

125.209.222.142

202.131.30.11

202.131.30.12

125.209.222.141

172:rp young$ 

Port check script by ruby

172:rp young$ cat port_check.rb 

#!/usr/bin/env ruby

require 'rubygems'

require 'net/ping'

if Net::Ping::TCP.new(ARGV[0],ARGV[1]).ping

   puts "Pong!"

else

   puts "No response"

end

172:rp young$ ruby port_check.rb www.google.com 80

Pong!

172:rp young$ 

Ping script with ruby

172:rp young$ cat ping.rb 

require 'rubygems'

require 'net/ping'

if Net::Ping::External.new(ARGV[0]).ping

   puts "Pong!"

else

   puts "No response"

end

172:rp young$ ruby ping.rb www.google.com

Pong!

172:rp young$ 

Simple DNS mx check

#!/usr/bin/env ruby

def check

 if ARGV[0] == nil

 abort 'plz input domain name'

 end

end

check

require 'resolv'

dns = Resolv::DNS.new

domain = ARGV[0]

dns.each_resource(domain, Resolv::DNS::Resource::IN::MX) do |mail_server|

 puts mail_server.exchange

end

#How to test

y-MacBook-Pro:rp young$ ruby mf.rb  

plz input domain name

y-MacBook-Pro:rp young$ ruby mf.rb yahoo.com

mta7.am0.yahoodns.net

mta5.am0.yahoodns.net

mta6.am0.yahoodns.net

y-MacBook-Pro:rp young$ ruby mf.rb nate.com

mx1.nate.com

uploading ftp files

#!/usr/bin/env ruby

#Very simple ftp upload program by ruby

if ARGV[0] == nil

 abort "\nInput ftp site ip or domain name"

elsif ARGV[1] == nil

 abort "\nInput the text file that you want to upload"

end

require 'net/ftp'

ftp = Net::FTP.new(ARGV[0])

ftp.passive = true

ftp.login 'yourname', 'yourpasswd'

ftp.chdir('/dir/to/you/want')

ftp.puttextfile(ARGV[1])

#ftp.putbinaryfile(ARGV[1])

ftp.list('*') { |file| puts file }

ftp.close

Adding multiple users with chef(bash and template,cookbook_file)-public key added

Forward
* This article  shows how to add multiple users by using chef recipe. I used 'template' and cookbook_file in this example.
  This post assumes that readers are already installed and configured chef-server and clients.
  In terms of security, this article may not be excellent. So, do use carefully. If you are in the situation that the security is the real issue, use the "data bag encryption" for public or private key. 

1. Create cookbook 

root@knife2:/home/young/chef-repo# knife cookbook create user add


2. Making templates/user.txt.erb

root@knife2:/home/young/chef-repo# vi cookbooks/useradd/templates/default/user.txt.erb 

user1:users_group

user2:users_group

user3:users_group

user4:users_group

3. Create authorized_keys file.
I used vi to paster public key. Could use scp or other method.
root@knife2:/home/young/chef-repo# vi cookbooks/useradd/templates/default/authorized_keys

blablabla……..^^

4. Lastly, I made recipes/default.rb 

root@knife2:/home/young/chef-repo# vi cookbooks/useradd/recipes/default.rb 

#

# Cookbook Name:: useradd

# Recipe:: default

#

# Copyright 2014, My Future Company

#

# All rights reserved - Do Not Redistribute

#

# Author ohyoungjooung@gmail.com

template '/root/users' do

    source 'user.txt.erb'

end

cookbook_file "/root/authorized_keys" do

    source "authorized_keys"

    mode 0600

end

bash 'useradding' do

    user "root"

    cwd "/root"

    code <<-EOH 

    check(){

     if [[ $?=="0" ]]

     then

      echo "$1 is successful"

     else 

      echo "failed to achive mission"

      exit 1 

     fi

    }

    groupadd users_group

    for i in $(cat users)

    do

    USER=`echo $i | cut -d':' -f1`

    GROUP=`echo $i | cut -d':' -f2`

    #RUN COMMAND OF useradd

    useradd $USER -g $GROUP -m

    check "$USER useradd"

    mkdir /home/$USER/.ssh

    check "$USER mkdir"

    cp authorized_keys /home/$USER/.ssh/

    check "$USER authcp"

    chmod 0700 /home/$USER/.ssh

    chown -R $USER /home/$USER/.ssh

    chmod 0600 /home/$USER/.ssh/authorized_keys

    done

    rm -f /root/users

    rm -f /root/authorized_keys

    EOH

end

5. Uploading useradd recipe and test

root@knife2:/home/young/chef-repo# knife cookbook upload useradd

Uploading useradd        [0.1.0]

Uploaded 1 cookbook

# On node of chef-clint1

root@chef-client1:~# chef-client -o useradd

  * bash[useradding] action run[2014-01-30T11:35:55+09:00] INFO: Processing bash[useradding] action run (useradd::default line 14)

[2014-01-30T11:35:55+09:00] INFO: bash[useradding] ran successfully

    - execute "bash"  "/tmp/chef-script20140130-8091-1449qkb"

[2014-01-30T11:35:55+09:00] INFO: Chef Run complete in 0.277210052 seconds

[2014-01-30T11:35:55+09:00] INFO: Running report handlers

[2014-01-30T11:35:55+09:00] INFO: Report handlers complete

Chef Client finished, 2 resources updated

root@chef-client1:~# cat /etc/passwd | grep user

user1:x:1003:1004::/home/user1:/bin/sh

user2:x:1004:1004::/home/user2:/bin/sh

user3:x:1005:1004::/home/user3:/bin/sh

user4:x:1006:1004::/home/user4:/bin/sh

root@chef-client1:~# 

6. Using knife bootstrap on chef-client2 server. If you already ssh setting like private an public key password authentication won't be necessary.

root@knife2:/home/young/chef-repo# knife bootstrap chef-client2 -r 'recipe[useradd]' -x young --sudo

Bootstrapping Chef on chef-client2

Failed to authenticate young - trying password auth

Enter your password: 

chef-client2 Starting Chef Client, version 11.8.2

chef-client2 resolving cookbooks for run list: ["useradd"]

chef-client2 Synchronizing Cookbooks:

chef-client2   - useradd

chef-client2 Compiling Cookbooks...

chef-client2 Converging 2 resources

chef-client2 Recipe: useradd::default

chef-client2   * template[/tmp/users] action create

chef-client2     - create new file /tmp/users

chef-client2     - update content in file /tmp/users from none to ebcaf0

chef-client2         --- /tmp/users 2014-01-30 11:43:59.452210250 +0900

chef-client2         +++ /tmp/chef-rendered-template20140130-11865-15ixyap 2014-01-30 11:43:59.452210250 +0900

chef-client2         @@ -1 +1,6 @@

chef-client2         +user1:users_group

chef-client2         +user2:users_group

chef-client2         +user3:users_group

chef-client2         +user4:users_group

chef-client2         +

chef-client2 

chef-client2   * bash[useradding] action run

chef-client2     - execute "bash"  "/tmp/chef-script20140130-11865-30nl8s"

chef-client2 

chef-client2 Chef Client finished, 2 resources updated

 *Conclusion

This recipe is not sufficient because it does not include password. 

But it maybe useful for sysadmins to add many users for multiple servers in no time.

https://github.com/ohyoungjooung2/useradd