Merge pull request #756 from basecamp/tidy-up-role-host-setup

Tidy up role and host commander setup

lib/kamal/commander.rb

@@ -3,11 +3,13 @@ require "active_support/core_ext/module/delegation"
 
 class Kamal::Commander
   attr_accessor :verbosity, :holding_lock, :hold_lock_on_error
+  delegate :hosts, :roles, :primary_host, :primary_role, :roles_on, :traefik_hosts, :accessory_hosts, to: :specifics
 
   def initialize
     self.verbosity = :info
     self.holding_lock = false
     self.hold_lock_on_error = false
+    @specifics = nil
   end
 
   def config
@@ -24,10 +26,12 @@ class Kamal::Commander
   attr_reader :specific_roles, :specific_hosts
 
   def specific_primary!
+    @specifics = nil
     self.specific_hosts = [ config.primary_host ]
   end
 
   def specific_roles=(role_names)
+    @specifics = nil
     if role_names.present?
       @specific_roles = Kamal::Utils.filter_specific_items(role_names, config.roles)
 
@@ -40,6 +44,7 @@ class Kamal::Commander
   end
 
   def specific_hosts=(hosts)
+    @specifics = nil
     if hosts.present?
       @specific_hosts = Kamal::Utils.filter_specific_items(hosts, config.all_hosts)
 
@@ -51,39 +56,6 @@ class Kamal::Commander
     end
   end
 
-  def primary_host
-    # Given a list of specific roles, make an effort to match up with the primary_role
-    specific_hosts&.first || specific_roles&.detect { |role| role == config.primary_role }&.primary_host || specific_roles&.first&.primary_host || config.primary_host
-  end
-
-  def primary_role
-    roles_on(primary_host).first
-  end
-
-  def roles
-    (specific_roles || config.roles).select do |role|
-      ((specific_hosts || config.all_hosts) & role.hosts).any?
-    end
-  end
-
-  def hosts
-    (specific_hosts || config.all_hosts).select do |host|
-      (specific_roles || config.roles).flat_map(&:hosts).include?(host)
-    end
-  end
-
-  def roles_on(host)
-    roles.select { |role| role.hosts.include?(host.to_s) }
-  end
-
-  def traefik_hosts
-    specific_hosts || config.traefik_hosts
-  end
-
-  def accessory_hosts
-    specific_hosts || config.accessories.flat_map(&:hosts)
-  end
-
   def accessory_names
     config.accessories&.collect(&:name) || []
   end
@@ -181,4 +153,8 @@ class Kamal::Commander
       SSHKit.config.command_map[:docker] = "docker" # No need to use /usr/bin/env, just clogs up the logs
       SSHKit.config.output_verbosity = verbosity
     end
+
+    def specifics
+      @specifics ||= Kamal::Commander::Specifics.new(config, specific_hosts, specific_roles)
+    end
 end

lib/kamal/commander/specifics.rb

@@ -0,0 +1,49 @@
+class Kamal::Commander::Specifics
+  attr_reader :primary_host, :primary_role, :hosts, :roles
+  delegate :stable_sort!, to: Kamal::Utils
+
+  def initialize(config, specific_hosts, specific_roles)
+    @config, @specific_hosts, @specific_roles = config, specific_hosts, specific_roles
+
+    @roles, @hosts = specified_roles, specified_hosts
+
+    @primary_host = specific_hosts&.first || primary_specific_role&.primary_host || config.primary_host
+    @primary_role = primary_or_first_role(roles_on(primary_host))
+
+    stable_sort!(roles) { |role| role == primary_role ? 0 : 1 }
+    stable_sort!(hosts) { |host| roles_on(host).any? { |role| role == primary_role } ? 0 : 1 }
+  end
+
+  def roles_on(host)
+    roles.select { |role| role.hosts.include?(host.to_s) }
+  end
+
+  def traefik_hosts
+    specific_hosts || config.traefik_hosts
+  end
+
+  def accessory_hosts
+    specific_hosts || config.accessories.flat_map(&:hosts)
+  end
+
+  private
+    attr_reader :config, :specific_hosts, :specific_roles
+
+    def primary_specific_role
+      primary_or_first_role(specific_roles) if specific_roles.present?
+    end
+
+    def primary_or_first_role(roles)
+      roles.detect { |role| role == config.primary_role } || roles.first
+    end
+
+    def specified_roles
+      (specific_roles || config.roles) \
+        .select { |role| ((specific_hosts || config.all_hosts) & role.hosts).any? }
+    end
+
+    def specified_hosts
+      (specific_hosts || config.all_hosts) \
+        .select { |host| (specific_roles || config.roles).flat_map(&:hosts).include?(host) }
+    end
+end

lib/kamal/utils.rb

@@ -74,4 +74,8 @@ module Kamal::Utils
 
     matches
   end
+
+  def stable_sort!(elements, &block)
+    elements.sort_by!.with_index { |element, index| [ block.call(element), index ] }
+  end
 end

test/commander_test.rb

@@ -119,9 +119,10 @@ class CommanderTest < ActiveSupport::TestCase
     configure_with(:deploy_primary_web_role_override)
 
     @kamal.specific_roles = [ "web_*" ]
-    assert_equal [ "web_chicago", "web_tokyo" ], @kamal.roles.map(&:name)
+    assert_equal [ "web_tokyo", "web_chicago" ], @kamal.roles.map(&:name)
     assert_equal "web_tokyo", @kamal.primary_role.name
     assert_equal "1.1.1.3", @kamal.primary_host
+    assert_equal [ "1.1.1.3", "1.1.1.4", "1.1.1.1", "1.1.1.2" ], @kamal.hosts
   end
 
   private