SSH proxy: allow using a bare hostname without root@

Otherwise we can't connect to the proxy as the local user and we can't
use ~/.ssh/config to set User directives.

Defaulting to root@ is hard to deprecate without introducing new config.
A clean break is probably clearest.

lib/kamal/configuration/docs/ssh.yml

@@ -29,8 +29,8 @@ ssh:
 
  # Proxy host
  #
- # Specified in the form <host> or <user>@<host>:
- proxy: root@proxy-host
+ # Specified in the form <host> or <user>@<host>
+ proxy: proxy-host
 
  # Proxy command
  #

lib/kamal/configuration/ssh.rb

@@ -19,9 +19,9 @@ def port
  end
 
  def proxy
- if (proxy = ssh_config["proxy"])
- Net::SSH::Proxy::Jump.new(proxy.include?("@") ? proxy : "root@#{proxy}")
- elsif (proxy_command = ssh_config["proxy_command"])
+ if proxy = ssh_config["proxy"]
+ Net::SSH::Proxy::Jump.new(proxy)
+ elsif proxy_command = ssh_config["proxy_command"]
  Net::SSH::Proxy::Command.new(proxy_command)
  end
  end

test/commands/app_test.rb

@@ -294,7 +294,7 @@ class CommandsAppTest < ActiveSupport::TestCase
 
  test "run over ssh with proxy" do
  @config[:ssh] = { "proxy" => "2.2.2.2" }
- assert_equal "ssh -J root@2.2.2.2 -t [email protected] -p 22 'ls'", new_command.run_over_ssh("ls", host: "1.1.1.1")
+ assert_equal "ssh -J 2.2.2.2 -t [email protected] -p 22 'ls'", new_command.run_over_ssh("ls", host: "1.1.1.1")
  end
 
  test "run over ssh with proxy user" do
@@ -304,7 +304,7 @@ class CommandsAppTest < ActiveSupport::TestCase
 
  test "run over ssh with custom user with proxy" do
  @config[:ssh] = { "user" => "app", "proxy" => "2.2.2.2" }
- assert_equal "ssh -J root@2.2.2.2 -t [email protected] -p 22 'ls'", new_command.run_over_ssh("ls", host: "1.1.1.1")
+ assert_equal "ssh -J 2.2.2.2 -t [email protected] -p 22 'ls'", new_command.run_over_ssh("ls", host: "1.1.1.1")
  end
 
  test "run over ssh with proxy_command" do

test/configuration/ssh_test.rb

@@ -30,7 +30,7 @@ class ConfigurationSshTest < ActiveSupport::TestCase
 
  test "ssh options with proxy host" do
  config = Kamal::Configuration.new(@deploy.tap { |c| c.merge!(ssh: { "proxy" => "1.2.3.4" }) })
- assert_equal "root@1.2.3.4", config.ssh.options[:proxy].jump_proxies
+ assert_equal "1.2.3.4", config.ssh.options[:proxy].jump_proxies
  end
 
  test "ssh options with proxy host and user" do