Add Proxy::Jump to simulate ProxyJump option in ssh_config

2 files changed, 104 insertions, 0 deletions

diff --git a/lib/net/ssh/proxy/jump.rb b/lib/net/ssh/proxy/jump.rb
new file mode 100644
index 0000000..01aefef
--- /dev/null
+++ b/lib/net/ssh/proxy/jump.rb
@@ -0,0 +1,53 @@
+require 'uri'
+require 'net/ssh/proxy/command'
+
+module Net; module SSH; module Proxy
+
+  # An implementation of a jump proxy. To use it, instantiate it,
+  # then pass the instantiated object via the :proxy key to
+  # Net::SSH.start:
+  #
+  #   require 'net/ssh/proxy/jump'
+  #
+  #   proxy = Net::SSH::Proxy::Jump.new('user@proxy')
+  #   Net::SSH.start('host', 'user', :proxy => proxy) do |ssh|
+  #     ...
+  #   end
+  class Jump < Command
+
+    # The jump proxies
+    attr_reader :jump_proxies
+
+    # Create a new socket factory that tunnels via multiple jump proxes as
+    # [user@]host[:port].
+    def initialize(jump_proxies)
+      @jump_proxies = jump_proxies
+    end
+
+    # Return a new socket connected to the given host and port via the jump
+    # proxy that was requested when the socket factory was instantiated.
+    def open(host, port, connection_options = nil)
+      build_proxy_command_equivalent(connection_options)
+      super
+    end
+
+    # We cannot build the ProxyCommand template until we know if the :config
+    # option was specified during `Net::SSH.start`.
+    def build_proxy_command_equivalent(connection_options = nil)
+      first_jump, extra_jumps = jump_proxies.split(",", 2)
+      config = connection_options && connection_options[:config]
+      uri = URI.parse("ssh://#{first_jump}")
+
+      template = "ssh"
+      template << " -l #{uri.user}"    if uri.user
+      template << " -p #{uri.port}"    if uri.port
+      template << " -J #{extra_jumps}" if extra_jumps
+      template << " -F #{config}" if config != true && config
+      template << " -W %h:%p "
+      template << uri.host
+
+      @command_line_template = template
+    end
+  end
+
+end; end; end
diff --git a/test/test_proxy_jump.rb b/test/test_proxy_jump.rb
new file mode 100644
index 0000000..3836303
--- /dev/null
+++ b/test/test_proxy_jump.rb
@@ -0,0 +1,51 @@
+require_relative 'common'
+require 'net/ssh/proxy/jump'
+
+class TestProxyJump < NetSSHTest
+  def test_is_a_proxy_command
+    proxy = Net::SSH::Proxy::Jump.new("user@jumphost")
+    assert proxy.is_a?(Net::SSH::Proxy::Command)
+  end
+
+  def test_host
+    proxy = Net::SSH::Proxy::Jump.new("jumphost")
+    proxy.build_proxy_command_equivalent
+    assert_equal "ssh -W %h:%p jumphost", proxy.command_line_template
+  end
+
+  def test_user_host
+    proxy = Net::SSH::Proxy::Jump.new("sally@proxy")
+    proxy.build_proxy_command_equivalent
+    assert_equal "ssh -l sally -W %h:%p proxy", proxy.command_line_template
+  end
+
+  def test_user_host_port
+    proxy = Net::SSH::Proxy::Jump.new("bob@jump:2222")
+    proxy.build_proxy_command_equivalent
+    assert_equal "ssh -l bob -p 2222 -W %h:%p jump", proxy.command_line_template
+  end
+
+  def test_multiple_jump_proxies
+    proxy = Net::SSH::Proxy::Jump.new("user1@proxy1,user2@proxy2,user3@proxy3")
+    proxy.build_proxy_command_equivalent
+    assert_equal "ssh -l user1 -J user2@proxy2,user3@proxy3 -W %h:%p proxy1", proxy.command_line_template
+  end
+
+  def test_config_override
+    proxy = Net::SSH::Proxy::Jump.new("proxy")
+    proxy.build_proxy_command_equivalent(config: "/home/user/.ssh/config2")
+    assert_equal "ssh -F /home/user/.ssh/config2 -W %h:%p proxy", proxy.command_line_template
+  end
+
+  def test_config_false
+    proxy = Net::SSH::Proxy::Jump.new("proxy")
+    proxy.build_proxy_command_equivalent(config: false)
+    assert_equal "ssh -W %h:%p proxy", proxy.command_line_template
+  end
+
+  def test_config_true
+    proxy = Net::SSH::Proxy::Jump.new("proxy")
+    proxy.build_proxy_command_equivalent(config: true)
+    assert_equal "ssh -W %h:%p proxy", proxy.command_line_template
+  end
+end