This is what I got so far. This works great, the problem being I can't input a password for the ssh login, I need to have shared ssh keys in order for this to work:
def ssh_conn(user, host, &block)
begin
ping_output = []
timeout(20) do
ping_output = IO.popen("ssh #{user}##{host} 'echo \"success\"'", "w+")
end
ping = ping_output.readlines.join[/success/] ? true : false
rescue Timeout::Error
ping = false
rescue
ping = false
end
ping_output.close
if block_given? && ping
yield
end
return ping
end
The question here is: How can I do something similar to this, but with password input through the arguments passed to the method? Preferably using ruby native Classes/Methods without installing any "external" gems.
By searching a bit in StackOverflow I've found this thread
and I was able to solve my problem doing this:
def ssh_try(user, host, pass)
puts "SSHing #{host} ..."
Net::SSH.start( host.to_s, user.to_s, :password => pass.to_s ) do |ssh|
puts ssh.exec!('date')
puts "Logging out..."
end
end
Anyone who is facing a similar problem can try this method, works great to test/use ssh connection in ruby.
I believe you cannot do that with ssh itself, but that's what sshpass it's for, as you can read in this serverfault answer. In Ubuntu:
$ sudo apt-get install sshpass
And then change your IO call like this:
ping_output = IO.popen("sshpass -p ssh #{user}##{host} 'echo \"success\"'", "w+")
An alternative would be to rewrite your code to use Ruby SSH client, such as net-ssh, instead of using the system command. This is actually my recommendation, since it'll allow you to work at a higher abstraction level and not deal with system issues. Also, the result looks more beautiful! Check this (untested) code:
require 'net/ssh'
def ssh_conn(user, host, password, &block)
authentication_successful = Net::SSH::Authentication::Session.authenticate(host, user, password)
authentication_successful && (yield if block_given?)
authentication_successful
end
Related
Using below function I can connect to my Linux machine.
But few commands need root permission to execute and direct root login is disabled. Also, the user cannot sudo.
require 'net/ssh'
def sshutm(host,un,pwd,cmd)
Net::SSH.start( host, un, :password => pwd ) do|ssh|
result = ssh.exec!(cmd)
return result
end
end
I tried this but it dint work.
def sshutm(host,un,pwd,cmd)
Net::SSH.start( host, un, :password => pwd ) do|ssh|
ssh.exec!("su")
ssh.exec!("passowrd")
result = ssh.exec!(cmd)
return result
end
end
You could make your user a sudo user (e.g. http://www.linux.com/learn/tutorials/306766:linux-101-introduction-to-sudo), and execute the given command with sudo (e.g. sudo ls /root). Details vary on the used distribution.
I have to take a dump of a service in sinatra and display it in the content area of the webpage.
The Service I have to access via code runs on server at port 6557. It doesnt use any encryption or authentication. Its a plain readonly request response thingy like http.
Here is what works in teminal
$ echo "GET hosts" | nc 192.168.1.1 6557
gives me the intended output. I need to do something similar using the sinatra application.
I wrote this code but is grossly incorrect. Can sombody help me with code or lookup materials or examples.
get '/' do
host = "192.168.1.1"
port = 6557
dat = ""
#socket = TCPSocket.open (host, port)
while(true)
if(IO.select([],[],[#socket],0))
socket.close
return
end
begin
while( (data = #socket.recv_nonblock(100)) != "")
dat = dat+ data
end
rescue Errno::EAGAIN
end
begin
#str = "GET hosts"
#socket.puts(#str);
rescue Errno::EAGAIN
rescue EOFError
exit
end
IO.select([#socket], [#socket], [#socket])
end
#line = dat
erb :info
end
The code on execution just hangs up.
Also if possible please give some links to read up to get a conceptual context of the problem.
I think the Ruby equivalent to your shell command should be as simple as:
require "socket"
socket = TCPSocket.new "192.168.1.1", 6557
socket.puts "GET hosts"
socket.read
According to the docs, #read should close the socket automatically, so you don't need to worry about doing that manually.
You can execute shell commands directly from ruby using backticks or the system command. Something like this may work for you:
get "/" do
#line = `echo "GET hosts" | nc 192.168.1.1 6557`
erb :info
end
Check out the ruby docs for Kernel#system for more info.
I am trying to execute an interactive shell program on a remote host from another ruby program. For the sake of simplicity let's suppose that the program I want to execute is something like this:
puts "Give me a number:"
number = gets.chomp()
puts "You gave me #{number}"
The approach that most successful has been so far is using the one I got from here. It is this one:
require 'open3'
Open3.popen3("ssh -tt root#remote 'ruby numbers.rb'") do |stdin, stdout, stderr|
# stdin = input stream
# stdout = output stream
# stderr = stderr stream
threads = []
threads << Thread.new(stderr) do |terr|
while (line = terr.gets)
puts "stderr: #{line}"
end
end
threads << Thread.new(stdout) do |terr|
while (line = terr.gets)
puts "stdout: #{line}"
end
end
sleep(2)
puts "Give me an answer: "
answer = gets.chomp()
stdin.puts answer
threads.each{|t| t.join()} #in order to cleanup when you're done.
end
The problem is that this is not "interactive" enough to me, and the program that I would like to execute (not the simple numbers.rb) has a lot more of input / output. You can think of it as an apt-get install that will ask you for some input to solve some problems.
I have read about net::ssh and pty, but couldn't see if they were going to be the (easy/elegant) solution I am looking for.
The ideal solution will be to make it in such a way that the user does not realize that the IO is being done on a remote host: the stdin goes to the remote host stdin, the stdout from the remote host comes to me and I show it.
If you have any ideas I could try I will be happy to hear them. Thank you!
Try this:
require "readline"
require 'open3'
Open3.popen3("ssh -tt root#remote 'ruby numbers.rb'") do |i, o, e, th|
Thread.new {
while !i.closed? do
input =Readline.readline("", true).strip
i.puts input
end
}
t_err = Thread.new {
while !e.eof? do
putc e.readchar
end
}
t_out = Thread.new {
while !o.eof? do
putc o.readchar
end
}
Process::waitpid(th.pid) rescue nil
# "rescue nil" is there in case process already ended.
t_err.join
t_out.join
end
I got it working, but don't ask me why it works. It was mainly trial/error.
Alternatives:
Using Net::SSH, you need to use :on_process and a Thread: ruby net/ssh channel dies? Don't forget to add session.loop(0.1). More info at the link. The Thread/:on_process idea inspired me to write a gem for my own use: https://github.com/da99/Chee/blob/master/lib/Chee.rb
If the last call in your Ruby program is SSH, then you can exec ssh -tt root#remote 'ruby numbers.rb'. But, if you still want interactivity between User<->Ruby<->SSH, then the previous alternative is the best.
I've got a script thats supposed to mimic ffmpeg on my local machine, by sending the command of to a remote machine, running it there and then returning the results.
(see previous stackoverflow question.)
#!/usr/bin/env ruby
require 'rubygems'
require 'net/ssh'
require 'net/sftp'
require 'highline/import'
file = ARGV[ ARGV.index( '-i' ) + 1] if ARGV.include?( '-i' )
puts 'No input file specified' unless file;
host = "10.0.0.10"
user = "user"
prod = "new-#{file}" # product filename (call it <file>-new)
rpath = "/home/#{user}/.rffmpeg" # remote computer operating directory
rfile = "#{rpath}/#{file}" # remote filename
rprod = "#{rpath}/#{prod}" # remote product
cmd = "ffmpeg -i #{rfile} #{rprod}"# remote command, constructed
pass = ask("Password: ") { |q| q.echo = false } # password from stdin
Net::SSH.start(host, user ) do |ssh|
ssh.sftp.connect do |sftp|
# upload local 'file' to remote 'rfile'
sftp.upload!(file, rfile)
# run remote command 'cmd' to produce 'rprod'
ssh.exec!(cmd)
# download remote 'rprod' to local 'prod'
sftp.download!(rprod, prod)
end
end
now my problem is at
ssh.exec!(cmd)
I want to display the cmd's output to the local user in real-time. But making it
puts ssh.exec!(cmd)
I only get the resulting output after the command has finished running. How would I have to change the code to make this work?
On the display side of your question, you can generate an updating progress bar in Ruby using the "\r" string char. This backs you up to the beginning of the current line allowing you to re-write it. For example:
1.upto(100) { |i| sleep 0.05; print "\rPercent Complete #{i}%"}
Or if you just want a progress bar across the screen you can simply do something similar to this:
1.upto(50) { sleep 0.05; print "|"}
Also, relating to stdout, in addition to flushing output per previous example (STDOUT.flush), you can ask Ruby to automatically sync writes to an IO buffer (in this case STDOUT) with associated device writes (basically turns off internal buffering):
STDOUT.sync = true
Also, I find that sometimes flush doesn't work for me, and I use "IO.fsync" instead. For me that's mostly been related to file system work, but it's worth knowing.
From ri Net::SSH::start:
-------------------------------------------------------- Net::SSH::start
Net::SSH::start(host, user, options={}, &block) {|connection| ...}
------------------------------------------------------------------------
The standard means of starting a new SSH connection. When used with
a block, the connection will be closed when the block terminates,
otherwise the connection will just be returned. The yielded (or
returned) value will be an instance of
Net::SSH::Connection::Session (q.v.). (See also
Net::SSH::Connection::Channel and Net::SSH::Service::Forward.)
Net::SSH.start("host", "user") do |ssh|
ssh.exec! "cp /some/file /another/location"
hostname = ssh.exec!("hostname")
ssh.open_channel do |ch|
ch.exec "sudo -p 'sudo password: ' ls" do |ch, success|
abort "could not execute sudo ls" unless success
ch.on_data do |ch, data|
print data
if data =~ /sudo password: /
ch.send_data("password\n")
end
end
end
end
ssh.loop
end
So it looks like you can get more interactive by using #open_channel
Here's some example code:
user#server% cat echo.rb
#! /usr/local/bin/ruby
def putsf s
puts s
STDOUT.flush
end
putsf "hello"
5.times do
putsf gets.chomp
end
putsf "goodbye"
And on your local machine:
user#local% cat client.rb
#! /usr/local/bin/ruby
require 'rubygems'
require 'net/ssh'
words = %w{ earn more sessions by sleaving }
index = 0;
Net::SSH.start('server', 'user') do |ssh|
ssh.open_channel do |ch|
ch.exec './echo.rb' do |ch, success|
abort "could not execute ./echo.rb" unless success
ch.on_data do |ch, data|
p [:data, data]
index %= words.size
ch.send_data( words[index] + "\n" )
index += 1
end
end
end
end
user#local% ./client.rb
[:data, "hello\n"]
[:data, "earn\n"]
[:data, "more\n"]
[:data, "sessions\n"]
[:data, "by\n"]
[:data, "sleaving\n"]
[:data, "goodbye\n"]
So you can interact with a running process this way.
It's important that the running process flush its output before requesting input - otherwise, the program might hang as the channel may not have received the unflushed output.
I need a quick way to find out if a given port is open with Ruby. I currently am fiddling around with this:
require 'socket'
def is_port_open?(ip, port)
begin
TCPSocket.new(ip, port)
rescue Errno::ECONNREFUSED
return false
end
return true
end
It works great if the port is open, but the downside of this is that occasionally it will just sit and wait for 10-20 seconds and then eventually time out, throwing a ETIMEOUT exception (if the port is closed). My question is thus:
Can this code be amended to only wait for a second (and return false if we get nothing back by then) or is there a better way to check if a given port is open on a given host?
Edit: Calling bash code is acceptable also as long as it works cross-platform (e.g., Mac OS X, *nix, and Cygwin), although I do prefer Ruby code.
Something like the following might work:
require 'socket'
require 'timeout'
def is_port_open?(ip, port)
begin
Timeout::timeout(1) do
begin
s = TCPSocket.new(ip, port)
s.close
return true
rescue Errno::ECONNREFUSED, Errno::EHOSTUNREACH
return false
end
end
rescue Timeout::Error
end
return false
end
All other existing answer are undesirable. Using Timeout is discouraged. Perhaps things depend on ruby version. At least since 2.0 one can simply use:
Socket.tcp("www.ruby-lang.org", 10567, connect_timeout: 5) {}
For older ruby the best method I could find is using non-blocking mode and then select. Described here:
https://spin.atomicobject.com/2013/09/30/socket-connection-timeout-ruby/
More Ruby idiomatic syntax:
require 'socket'
require 'timeout'
def port_open?(ip, port, seconds=1)
Timeout::timeout(seconds) do
begin
TCPSocket.new(ip, port).close
true
rescue Errno::ECONNREFUSED, Errno::EHOSTUNREACH
false
end
end
rescue Timeout::Error
false
end
I recently came up with this solution, making use of the unix lsof command:
def port_open?(port)
!system("lsof -i:#{port}", out: '/dev/null')
end
Just for completeness, the Bash would be something like this:
$ netcat $HOST $PORT -w 1 -q 0 </dev/null && do_something
-w 1 specifies a timeout of 1 second, and -q 0 says that, when connected, close the connection as soon as stdin gives EOF (which /dev/null will do straight away).
Bash also has its own built-in TCP/UDP services, but they are a compile-time option and I don't have a Bash compiled with them :P
My slight variation to Chris Rice's answer. Still handles timing out on a single attempt but also allows multiple retries until you give up.
def is_port_open?(host, port, timeout, sleep_period)
begin
Timeout::timeout(timeout) do
begin
s = TCPSocket.new(host, port)
s.close
return true
rescue Errno::ECONNREFUSED, Errno::EHOSTUNREACH
sleep(sleep_period)
retry
end
end
rescue Timeout::Error
return false
end
end
All *nix platforms:
try nc / netcat command as follow.
`nc -z -w #{timeout_in_seconds} -G #{timeout_in_seconds} #{host} #{port}`
if $?.exitstatus == 0
#port is open
else
#refused, port is closed
end
The -z flag can be used to tell nc to report open ports, rather than initiate a connection.
The -w flag means Timeout for connects and final net reads
The -G flag is connection timeout in seconds
Use -n flag to work with IP address rather than hostname.
Examples:
# `nc -z -w 1 -G 1 google.com 80`
# `nc -z -w 1 -G 1 -n 123.234.1.18 80`
My solution is derived from the posted solutions.
require 'socket'
def is_port_open?(ip, port)
begin
s = Socket.tcp(ip, port, connect_timeout: 5)
s.close
return true
rescue => e
# possible exceptions:
# - Errno::ECONNREFUSED
# - Errno::EHOSTUNREACH
# - Errno::ETIMEDOUT
puts "#{e.class}: #{e.message}"
return false
end
end