SSL is only supported on a single server or with custom SSL certificates

lib/kamal/configuration/proxy.rb

@@ -22,6 +22,10 @@ def ssl?
  proxy_config.fetch("ssl", false)
  end
 
+ def custom_ssl_certificate?
+ proxy_config["ssl_certificate_path"].present?
+ end
+
  def hosts
  proxy_config["hosts"] || proxy_config["host"]&.split(",") || []
  end

lib/kamal/configuration/role.rb

@@ -150,8 +150,8 @@ def asset_volume_directory(version = config.version)
  end
 
  def ensure_one_host_for_ssl
- if running_proxy? && proxy.ssl? && hosts.size > 1
- raise Kamal::ConfigurationError, "SSL is only supported on a single server, found #{hosts.size} servers for role #{name}"
+ if running_proxy? && proxy.ssl? && hosts.size > 1 && !proxy.custom_ssl_certificate?
+ raise Kamal::ConfigurationError, "SSL is only supported on a single server or with custom SSL certificates, found #{hosts.size} servers for role #{name}"
  end
  end
 

test/configuration_test.rb

@@ -371,7 +371,16 @@ class ConfigurationTest < ActiveSupport::TestCase
  Kamal::Configuration.new(@deploy_with_roles)
  end
 
- assert_equal "SSL is only supported on a single server, found 2 servers for role workers", exception.message
+ assert_equal "SSL is only supported on a single server or with custom SSL certificates, found 2 servers for role workers", exception.message
+ end
+
+ test "proxy ssl roles with multiple servers and a custom SSL certificate" do
+ @deploy_with_roles[:servers]["workers"]["proxy"] = { "ssl" => true, "host" => "foo.example.com", "ssl_certificate_path" => "/path/to/cert.pem", "ssl_private_key_path" => "/path/to/key.pem" }
+
+ config = Kamal::Configuration.new(@deploy_with_roles)
+
+ assert config.role(:workers).running_proxy?
+ assert config.role(:workers).ssl?
  end
 
  test "two proxy ssl roles with same host" do