Module: Open4ssh

Defined in:
lib/open4ssh.rb,
lib/open4ssh/version.rb

Constant Summary collapse

VERSION = 
"0.1.2"

Class Method Summary collapse

Class Method Details

.capture(host: '', user: '', port: 22, key: '', pwd: '', cmd: '') ⇒ String

Executes a shell command on a remote host via SSH and captures the console output.

Examples:

stdout = Open4ssh.capture(
    host: 'remote.host.io',
    user: 'nane',
    pwd: 'secret',
    cmd: 'ls -la'
)
puts stdout



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# File 'lib/open4ssh.rb', line 26

def self.capture(host: '', user: '', port: 22, key: '', pwd: '', cmd: '')
  stdout = ""
  keys = [key]

  Net::SSH.start(host, user, port: 22, password: pwd, keys: keys) do |ssh|
    result = ssh.exec!(cmd)
    stdout = result
  end

  return stdout
end

.capture4(host: '', user: '', port: 22, key: '', pwd: '', cmd: [], verbose: false) ⇒ Array<exit_code, std_out, std_err, command>

Executes a list of shell commands on a remote host via SSH and captures their exit codes, stdouts and stderrs. The commands are executed sequentially until a command terminates with an exit code not equal 0 (no success).

Examples:

exit_code, stderr, stdout, command = Open4ssh.capture4(
  host: 'remote.host.io',
  user: 'nane',
  key: '/path/to/your/sshkey.pem',
  cmd: [
  "touch helloworld.txt",
  "cat helloworld.txt",
  "echo 'Hello World' >> helloworld.txt",
  "cat helloworld.txt",
  "rm helloworld.txt"
]).last



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# File 'lib/open4ssh.rb', line 64

def self.capture4(host: '', user: '', port: 22, key: '', pwd: '', cmd: [], verbose: false)
  keys    = [key]
  results = []

  Net::SSH.start(host, user, port: port, password: pwd, keys: keys) do |ssh|
    # Execute command by command
    for command in cmd
      stdout   = ""
      stderr   = ""
      code     = nil
      channel = ssh.open_channel do |ch|
        ch.exec(command) do |c, success|
          c.close unless success

          c.on_data do |_, data|
            stdout += data
            $stdout.puts(data) if verbose
          end

          c.on_extended_data do |_, _, data|
            stderr += data
            $stderr.puts(data) if verbose
          end

          c.on_request('exit-status') { |_, data| code = data.read_long }
        end
      end
      channel.wait
      results << [code, stdout, stderr, command]

      # If last command was not successful stop execution
      if code != 0
        ssh.close
        return results
      end
    end
  end

  return results
end

.console(results) ⇒ String

Collects all console messages (stdout + stderr) of a list of executed shell commands.

Examples:

ecodes = Open4ssh.capture4(
  host: 'remote.host.io',
  user: 'nane',
  key: '/path/to/your/sshkey.pem',
  cmd: [
    "touch helloworld.txt",
    "cat helloworld.txt",
    "echo 'Hello World' >> helloworld.txt",
    "cat helloworld.txt",
    "rm helloworld.txt"
])

puts Open4ssh.console(ecodes) # Print collected console messages of all executed commands



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# File 'lib/open4ssh.rb', line 216

def self.console(results)
  output = results.map { |result| "#{result[1]}\n#{result[2]}" }
               .select { |console| not console.strip.empty? } * "\n"
  output.strip
end

.stderr(results) ⇒ String

Collects all stderr messages of a list of executed shell commands.

Examples:

ecodes = Open4ssh.capture4(
  host: 'remote.host.io',
  user: 'nane',
  key: '/path/to/your/sshkey.pem',
  cmd: [
    "touch helloworld.txt",
    "cat helloworld.txt",
    "this will fail",
    "cat helloworld.txt",
    "rm helloworld.txt"
])

unless Open4ssh.success(ecodes)
   puts "Failure:"
   puts Open4ssh.stderr(ecodes) # Print collected stderr messages of all executed commands
end



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# File 'lib/open4ssh.rb', line 189

def self.stderr(results)
  output = results.map { |result| result[2] }
               .select { |stderr| not stderr.strip.empty? } * "\n"
  output.strip
end

.stdout(results) ⇒ String

Collects all stdout messages of a list of executed shell commands.

Examples:

ecodes = Open4ssh.capture4(
  host: 'remote.host.io',
  user: 'nane',
  key: '/path/to/your/sshkey.pem',
  cmd: [
    "touch helloworld.txt",
    "cat helloworld.txt",
    "echo 'Hello World' >> helloworld.txt",
    "cat helloworld.txt",
    "rm helloworld.txt"
])

if Open4ssh.success(ecodes)
   puts "Success:"
   puts Open4ssh.stdout(ecodes) # Print collected stdout messages of all executed commands
end



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# File 'lib/open4ssh.rb', line 159

def self.stdout(results)
  output = results.map { |result| result[1] }
               .select {  |stdout| not stdout.strip.empty? } * "\n"
  output.strip
end

.success(results) ⇒ Bool

Determines whether a list of shell commands has been executed successfully.

Examples:

ecodes = Open4ssh.capture4(
  host: 'remote.host.io',
  user: 'nane',
  key: '/path/to/your/sshkey.pem',
  cmd: [
    "touch helloworld.txt",
    "cat helloworld.txt",
    "echo 'Hello World' >> helloworld.txt",
    "cat helloworld.txt",
    "rm helloworld.txt"
])

if Open4ssh.success(ecodes)
   puts "Success:"
   puts Open4ssh.console(ecodes) # Print collected console outputs of all executed commands
end



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# File 'lib/open4ssh.rb', line 130

def self.success(results)
  results.select { |result| result[0] != 0 }
      .empty?
end