editWe assume that there are machines organized like below.
* Admin machine: 1 host
* The sample code is executed on this machine
* Managed machine: 3 host
* sunagimo01: 192.168.2.1
* sunagimo02: 192.168.2.2
* sunagimo03: 192.168.2.3
* #all managed machines can be logined as user "bob" whose password is "bar"
* #Requirements for managed machines are accessibility through SSH and file transfer with SFTP
Here, we perform operations below to all managed machines.
* 1.Installation of some packages
* 2.Editing of configuration file
* 3.Execution of experiment program
* Transfer /home/taro/scenario.sh on admin machine to managed machines and executes them
* echo "`hostname`: Hello svengali!!"
* #each step is executed serial
Code for above operations can be written like below.
{{{ code ruby
#! /bin/ruby
require "rubygems"
require "svengali"
user_name = "bob"
password = "bar"
# use IP addres due to access by sequence number
IPADDR_BASE = CLibIPAddr.new("192.168.2.1")
MACHINE_NUM = 3
nodes = Array.new(MACHINE_NUM)
tmp_ipaddr = IPADDR_BASE.dup()
MACHINE_NUM.times{ |n|
# FQDN machine name can be also passed
nodes[n] = Machine.new(tmp_ipaddr)
nodes[n].set_auth_info(user_name,password)
# establishes a transport for command execution via SSH
nodes[n].establish_session()
# install package
# package system used is default one(yum)
puts nodes[n].install_package("openmpi")
tmp_ipaddr.inc!()
}
nodes.each{ |a_node|
# edit configuration file( sshd_config )
sshd_conf = a_node.get_config_file("/etc/ssh/sshd_config")
sshd_conf.replace_col("X11Forwarding yes","X11Forwarding no")
sshd_conf.save()
}
# start experiment
nodes.each{ |a_node|
# bonus
puts a_node.exec!("uname -a")
# executes experiment script
puts a_node.exec_script_on("/home/taro/scenario.sh","","/home/taro")
}
}}}
[[BR]]
Execution result
{{{
$ruby test_svengali.rb
( --- omitted yum outputs --- )
Linux sunagimo01 2.6.32-22-generic #33-Ubuntu SMP Wed Jan 21 10:44:23 EST 2009
sunagimo01: Hello svengali!!
Linux sunagimo02 2.6.32-22-generic #33-Ubuntu SMP Wed Jan 21 10:44:35 EST 2009
sunagimo02: Hello svengali!!
Linux sunagimo03 2.6.32-22-generic #33-Ubuntu SMP Wed Jan 21 10:44:47 EST 2009
sunagimo03: Hello svengali!!
}}}
[[BR]]
Operation of network configuration can be written like below.
{{{ code ruby
( --- codes same as former sample code are omitted --- )
gateway_addr = CLibIPAddr.new("xxx.xxx.xxx.xxx")
dns_addr = CLibIPAddr.new("xxx.xxx.xxx.xxx")
netmask_addr = CLibIPAddr.new("xxx.xxx.xxx.xxx")
CHANGED_IPADDR_BASE = CLibIPAddr.new("xxx.xxx.xxx.xxx")
tmp_ipaddr = CHANGED_IPADDR_BASE.dup()
nodes.each{ |a_node|
# set a IP address in sequence
a_node.config_nw_interface(:ipaddr => tmp_ipaddr , :interface => "eth0", :netmask => netmask_addr, :gateway => gateway_addr, :onboot => "yes")
a_node.set_resolver(:primary_ip => dns_addr)
# reload network configuration of each machine
# returns after 10 seconds ( use timeout due to avoid implementation problem of Machine class around SSH connection)
a_node.exec!("/sbin/service network restart", 10)
tmp_ipaddr.inc!()
}
# reestablish connection with using new addresses
tmp_ipaddr = CHANGED_IPADDR_BASE.dup()
nodes_changed = Array.new(MACHINE_NUM)
nodes_changed.each{ |a_node|
a_node = Machine.new(tmp_ipaddr.to_s)
a_node.set_auth_info(user_name,password)
a_node.establish_session()
tmp_ipaddr.inc!()
puts a_node.exec!("/sbin/ifconfig eth0")
}
}}}