Cannot connect to remote db using ssh tunnel and a

问题:

I'm having some trouble with the following script:

require 'rubygems'
require 'active_record'
require 'net/ssh/gateway'

gateway = Net::SSH::Gateway.new('myserver.com', 'myuser', :password => "mypass")
puts "true" if gateway.active?
p = gateway.open('127.0.0.1', 3306, 3307)

class MyClass < ActiveRecord::Base
  establish_connection(
    :adapter  => "mysql",
    :host     => "127.0.0.1",
    :username => "db_user",
    :password => "db_pass",
    :database => "mydb_production",
    :port     => 3307
  )
end

puts MyClass.all.size

gateway.shutdown!

When I run the script it just hangs, unless I remove the activerecord query. I know I can connect using tunneling because I can create a tunnel from the command like like so:

ssh -f [e-mail] -L 3307/127.0.0.1/3306 -N

Then if I run:

require 'rubygems'
require 'active_record'

class MyClass < ActiveRecord::Base
  establish_connection(
    :adapter  => "mysql",
    :host     => "127.0.0.1",
    :username => "db_user",
    :password => "db_pass",
    :database => "mydb_production",
    :port     => 3307
  )
end

puts MyClass.all.size

It works fine. What am I doing wrong?

Thanks.

回答1:

I was able to get this to work without a fork by using the mysql2 gem

require 'rubygems'
require 'active_record'
require 'mysql2'
require 'net/ssh/gateway'

gateway = Net::SSH::Gateway.new(
  'remotehost.com',
  'username'
)
port = gateway.open('127.0.0.1', 3306, 3307)

class Company < ActiveRecord::Base
  establish_connection(
    :adapter  => "mysql2",
    :host     => "127.0.0.1",
    :username => "dbuser",
    :password => "dbpass",
    :database => "dbname",
    :port     => 3307
  )
end
puts Company.all.size

回答2:

I think the comment is right - the DB is conflicting with the event loop in the ssh code.

Try this:

  require 'rubygems'
  require 'active_record'
  require 'net/ssh/gateway'

  gateway = Net::SSH::Gateway.new('myserver.com', 'myuser', :password => "mypass")
  puts "true" if gateway.active?
  port = gateway.open('127.0.0.1', 3306, 3307)
  fork.do
    class MyClass < ActiveRecord::Base
      establish_connection(
        :adapter  => "mysql",
        :host     => "127.0.0.1",
        :username => "db_user",
        :password => "db_pass",
        :database => "mydb_production",
        :port     => 3307
      )
    end

    puts MyClass.all.size
  end  

  Process.wait

  gateway.shutdown!