Merge pull request #222 from basecamp/deploy-groups

Allow booting containers in groups for rolling restarts

lib/mrsk/cli/app.rb

@@ -11,7 +11,7 @@ class Mrsk::Cli::App < Mrsk::Cli::Base
           execute *MRSK.app.tag_current_as_latest
         end
 
-        on(MRSK.hosts) do |host|
+        on(MRSK.hosts, **MRSK.boot_strategy) do |host|
           roles = MRSK.roles_on(host)
 
           roles.each do |role|

lib/mrsk/commander.rb

@@ -51,6 +51,14 @@ class Mrsk::Commander
     end
   end
 
+  def boot_strategy
+    if config.boot.limit.present?
+      { in: :groups, limit: config.boot.limit, wait: config.boot.wait }
+    else
+      {}
+    end
+  end
+
   def roles_on(host)
     roles.select { |role| role.hosts.include?(host.to_s) }.map(&:name)
   end

lib/mrsk/configuration.rb

@@ -87,6 +87,10 @@ class Mrsk::Configuration
     roles.select(&:running_traefik?).flat_map(&:hosts).uniq
   end
 
+  def boot
+    Mrsk::Configuration::Boot.new(config: self)
+  end
+
 
   def repository
     [ raw_config.registry["server"], image ].compact.join("/")

lib/mrsk/configuration/boot.rb

@@ -0,0 +1,20 @@
+class Mrsk::Configuration::Boot
+  def initialize(config:)
+    @options = config.raw_config.boot || {}
+    @host_count = config.all_hosts.count
+  end
+
+  def limit
+    limit = @options["limit"]
+
+    if limit.to_s.end_with?("%")
+      @host_count * limit.to_i / 100
+    else
+      limit
+    end
+  end
+
+  def wait
+    @options["wait"]
+  end
+end