Module: SshDevice

Included in:
Brocade::SAN::Switch
Defined in:
lib/brocadesan/device.rb,
lib/brocadesan/device.rb

Overview

Basic wrapper class that runs SSH queries on the device and returns Response

It is used to extend further classes with SSH query mechanism

Defined Under Namespace

Classes: Error, Response

Constant Summary collapse

DEFAULT_QUERY_PROMPT =

default query prompt that will preceed each command started by query in the Response data

value is “> ”

This way the parser can separate from commands and data. The default will work everwhere where the retunned data is not prepended by “> ”

Ignore the ssh prompt like this: super_server(admin)> cmd super_server(admin)> data

This on the other hand would be problem. In this case override the prompt super_server(admin)> cmd super_server(admin)>> data

"> "

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#prompt ⇒ Object (readonly)

Returns the value of attribute prompt.



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# File 'lib/brocadesan/device.rb', line 25

def prompt
  @prompt
end

Instance Method Details

#get_mode ⇒ Object

get current query mode

returns either interactive or script

default mode is script



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# File 'lib/brocadesan/device.rb', line 51

def get_mode
  [true,false].include?(@opts[:interactive]) ? (@opts[:interactive]==true ? "interactive" : "script") : "script"
end

#initialize(address, user, password, opts = {}) ⇒ Object

Initialization method

opts can be:

:interactive

true / false will use interactive query can be set later

:prompt

prompt will override the DEFAULT_QUERY_PROMPT



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# File 'lib/brocadesan/device.rb', line 36

def initialize(address,user,password,opts={}) 
    @address=address
    @user=user
    @password=password
    @opts=opts
    @session=nil
    @session_level=0
    @prompt = opts[:prompt] ? opts[:prompt].to_s : DEFAULT_QUERY_PROMPT
end

#interactive_mode(&block) ⇒ Object

Defines a block of code to run in interactive mode

the mode will be reverted back to initial mode after leaving the block



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# File 'lib/brocadesan/device.rb', line 146

def interactive_mode(&block)
  run_in_mode :interactive, &block
end

#query(*cmds) ⇒ Object

Queries cmds commands directly. This method is to be used to implement higlevel API or to do more difficult queries that have to be parsed separately and for which there is now highlevel API

When started in interactive mode be sure the command is followed by inputs for that command. If command will require additional input and there is not one provided the prompt will receive enter. It will do this maximum of 100 times, then it gives up and returns whatever it got until then.

Query command will open connection to device if called outside session block or use existing session if called within session block.

Example:

>> class Test
>>   include SshDevice
>> end
>> device = Test.new("address","user","password")
>> device.query("switchname")
=> #<Test::Response:0x2bb1e00 @errors="", @data="> switchname\nsanswitchA\n", @parsed={:parsing_position=>"end"}>

Returns instance of Response or raises Error if the connection cannot be opened

Raises Error if SSH returns error. SSH error will be available in the exception message

Raises:

  • (self.class::Error) 


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# File 'lib/brocadesan/device.rb', line 90

def query(*cmds)
  output=nil
  if session_exist?
    output=exec(@session,cmds)
  else
    Net::SSH.start @address, @user, :password=>@password do |ssh|
      output=exec(ssh,cmds)
    end
  end
  
  raise self.class::Error.new(output.errors) if !output.errors.empty?
  
  return output
end

#script_mode(&block) ⇒ Object

Defines a block of code to run in script mode

the mode will be reverted back to initial mode after leaving the block



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# File 'lib/brocadesan/device.rb', line 139

def script_mode(&block)
  run_in_mode :script, &block
end

#session(&block) ⇒ Object

Opens a session block

All queries within the session block use the same connection. This speeds up the query processing.

The connection is closed at the end of the block

The command supports session blocks within session blocks. Session will be closed only at the last block

Example:

device.session do 
  device.query("switchname")
  device.version
end

Must receive block, raises SshDevice::Error otherwise



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# File 'lib/brocadesan/device.rb', line 120

def session(&block)
  raise Error.no_block if !block_given?
  begin 
    @session_level+=1 
    if !session_exist?
      @session=Net::SSH.start @address, @user, :password=>@password
    end
    yield
  rescue => e
    raise e
  ensure
    @session_level-=1
    @session.close if @session && @session_level==0 && !@session.closed?
  end
end

#set_mode(mode) ⇒ Object

sets current query mode

mode: interactive or script

interactive - used to do interactive queries in scripted manner by providing all responses in advance, see #query



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# File 'lib/brocadesan/device.rb', line 61

def set_mode(mode)
  @opts[:interactive] = mode.to_s == "interactive" ? true : false
  get_mode
end