Ruby Net :: SSH重用会话

Question

I have a few methods doing this:

def method_a
    Net::SSH.start(...) do |ssh|
    end
end

def method_b
    Net::SSH.start(...) do |ssh|
    end
end
def method_c
    Net::SSH.start(...) do |ssh|
    end
end

Each methods call Net::SSH start which are individual SSH sessions, doing different things.

Is there a way to reuse Net::SSH session so that all 3 methods utilize a single session?

THanks.

Answer 1

Yes, definitely you can make it DRY.

You can add one method which accept hostname for the Net::SSH connection as below:

def ssh_exec(hostname)

  Net::SSH.start( hostname, 'user', :timeout => 5, :paranoid => false ) do |ssh|

   ....
  end
end

Then you can call this method ssh_exec() with proper hostname wherever you need it...

Answer 2

The way to go in Net::SSH is to put

@ssh_session = Net::SSH.start( @host, nil, option={:config => true})

to a variable and then on each methods

def method_a
    @ssh_session.exec!("Hello a")
end

def method_b
     @ssh_session.exec!("Hello b")
end
def method_c
     @ssh_session.exec!("Hello c")
end

And of course i place all the above in a class, so that I can initialize and start a ssh session and exec commands without re-establishing SSH.

Answer 3

Outside a class, you can try:

def call
  Net::SSH.start(...) do |ssh|
    method_a(ssh)
    method_b(ssh)
    method_c(ssh)
  end
end

def method_a(ssh)
  ssh.exec(...) 
end

def method_b(ssh)
   ssh.exec(...)
end

def method_c(ssh)
   ssh.exec(...)
end

If it's in a class, you can define `attr_reader :ssh` and then initialize it thus:

def method_a
  ssh.exec(...)
end

With that, you can simply define

 def method_a ssh.exec(...) end 

Same applies for other methods. I hope this helps?