Add custom labels

README.md

@@ -93,6 +93,33 @@ servers:
 
 Traefik will only be installed and run on the servers in the `web` role (and on all servers if no roles are defined).
 
+### Adding custom container labels
+
+You can specialize the default Traefik rules by setting custom labels on the containers that are being started:
+
+```
+labels:
+  traefik.http.routers.hey.rule: 'Host(`app.hey.com`)'
+```
+
+This allows you to run multiple applications on the same server sharing the same Traefik instance and port.
+
+The labels can even be applied on a per-role basis:
+
+```yaml
+servers:
+  web:
+    - 192.168.0.1
+    - 192.168.0.2
+  job:
+    hosts:
+      - 192.168.0.3
+      - 192.168.0.4
+    cmd: bin/jobs
+    labels:
+      my-custom-label: "50"
+```
+
 ## Commands
 
 ### Remote execution

lib/mrsk/configuration.rb

@@ -3,7 +3,7 @@ require "active_support/core_ext/string/inquiry"
 require "erb"
 
 class Mrsk::Configuration
-  delegate :service, :image, :servers, :env, :registry, to: :config, allow_nil: true
+  delegate :service, :image, :servers, :env, :labels, :registry, to: :config, allow_nil: true
 
   class << self
     def load_file(file)

lib/mrsk/configuration/role.rb

@@ -11,6 +11,14 @@ class Mrsk::Configuration::Role
     @hosts ||= extract_hosts_from_config
   end
 
+  def labels
+    if name.web?
+      default_labels.merge(traefik_labels).merge(custom_labels)
+    else
+      default_labels.merge(custom_labels)
+    end
+  end
+
   def label_args
     argumentize "--label", labels
   end
@@ -31,14 +39,6 @@ class Mrsk::Configuration::Role
       end
     end
 
-    def labels
-      if name.web?
-        default_labels.merge(traefik_labels) 
-      else
-        default_labels
-      end
-    end
-
     def default_labels
       { "service" => config.service, "role" => name }
     end
@@ -53,6 +53,13 @@ class Mrsk::Configuration::Role
       }
     end
 
+    def custom_labels
+      Hash.new.tap do |labels|
+        labels.merge!(config.labels) if config.labels.present?
+        labels.merge!(specializations["labels"]) if specializations["labels"].present?
+      end
+    end
+
     def specializations
       if config.servers.is_a?(Array) || config.servers[name].is_a?(Array)
         { }

test/configuration_role_test.rb

@@ -30,6 +30,11 @@ class ConfigurationRoleTest < ActiveSupport::TestCase
     assert_equal [ "1.1.1.3", "1.1.1.4" ], @config_with_roles.role(:workers).hosts
   end
 
+  test "cmd" do
+    assert_nil @config.role(:web).cmd
+    assert_equal "bin/jobs", @config_with_roles.role(:workers).cmd
+  end
+
   test "label args" do
     assert_equal [ "--label", "service=app", "--label", "role=workers" ], @config_with_roles.role(:workers).label_args
   end
@@ -38,8 +43,19 @@ class ConfigurationRoleTest < ActiveSupport::TestCase
     assert_equal [ "--label", "service=app", "--label", "role=web", "--label", "traefik.http.routers.app.rule='PathPrefix(`/`)'", "--label", "traefik.http.services.app.loadbalancer.healthcheck.path=/up", "--label", "traefik.http.services.app.loadbalancer.healthcheck.interval=1s", "--label", "traefik.http.middlewares.app.retry.attempts=3", "--label", "traefik.http.middlewares.app.retry.initialinterval=500ms"], @config.role(:web).label_args
   end
 
-  test "cmd" do
-    assert_nil @config.role(:web).cmd
-    assert_equal "bin/jobs", @config_with_roles.role(:workers).cmd
+  test "custom labels" do
+    @deploy[:labels] = { "my.custom.label" => "50" }
+    assert_equal "50", @config.role(:web).labels["my.custom.label"]
+  end
+
+  test "custom labels via role specialization" do
+    @deploy_with_roles[:labels] = { "my.custom.label" => "50" }
+    @deploy_with_roles[:servers]["workers"]["labels"] = { "my.custom.label" => "70" }
+    assert_equal "70", @config_with_roles.role(:workers).labels["my.custom.label"]
+  end
+
+  test "overwriting default traefik label" do
+    @deploy[:labels] = { "traefik.http.routers.app.rule" => "'Host(`example.com`) || (Host(`example.org`) && Path(`/traefik`))'" }
+    assert_equal "'Host(`example.com`) || (Host(`example.org`) && Path(`/traefik`))'", @config.role(:web).labels["traefik.http.routers.app.rule"]
   end
 end