Allow Kamal to run without traefik

lib/kamal/cli/healthcheck.rb

@@ -3,6 +3,7 @@ class Kamal::Cli::Healthcheck < Kamal::Cli::Base
 
   desc "perform", "Health check current app version"
   def perform
+    raise "The primary host is not configured to run Traefik" unless KAMAL.config.role(KAMAL.config.primary_role).running_traefik?
     on(KAMAL.primary_host) do
       begin
         execute *KAMAL.healthcheck.run

lib/kamal/cli/main.rb

@@ -38,8 +38,10 @@ def deploy
         say "Ensure Traefik is running...", :magenta
         invoke "kamal:cli:traefik:boot", [], invoke_options
 
-        say "Ensure app can pass healthcheck...", :magenta
-        invoke "kamal:cli:healthcheck:perform", [], invoke_options
+        if KAMAL.config.role(KAMAL.config.primary_role).running_traefik?
+          say "Ensure app can pass healthcheck...", :magenta
+          invoke "kamal:cli:healthcheck:perform", [], invoke_options
+        end
 
         say "Detect stale containers...", :magenta
         invoke "kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true)

lib/kamal/cli/templates/deploy.yml

@@ -84,13 +84,12 @@ registry:
 #   limit: 10 # Can also specify as a percentage of total hosts, such as "25%"
 #   wait: 2
 
-# Configure the role used to determine the primary_web_host. This host takes
+# Configure the role used to determine the primary_host. This host takes
 # deploy locks, runs health checks during the deploy, and follow logs, etc.
-# This role should have traefik enabled.
 #
 # Caution: there's no support for role renaming yet, so be careful to cleanup
 #          the previous role on the deployed hosts.
-# primary_web_role: web
+# primary_role: web
 
 # Controls if we abort when see a role with no hosts. Disabling this may be
 # useful for more complex deploy configurations.

lib/kamal/commander.rb

@@ -24,7 +24,7 @@ def configure(**kwargs)
   attr_reader :specific_roles, :specific_hosts
 
   def specific_primary!
-    self.specific_hosts = [ config.primary_web_host ]
+    self.specific_hosts = [ config.primary_host ]
   end
 
   def specific_roles=(role_names)
@@ -36,7 +36,7 @@ def specific_hosts=(hosts)
   end
 
   def primary_host
-    specific_hosts&.first || specific_roles&.first&.primary_host || config.primary_web_host
+    specific_hosts&.first || specific_roles&.first&.primary_host || config.primary_host
   end
 
   def primary_role

lib/kamal/commands/healthcheck.rb

@@ -1,20 +1,20 @@
 class Kamal::Commands::Healthcheck < Kamal::Commands::Base
 
   def run
-    web = config.role(config.primary_web_role)
+    primary = config.role(config.primary_role)
 
     docker :run,
       "--detach",
       "--name", container_name_with_version,
       "--publish", "#{exposed_port}:#{config.healthcheck["port"]}",
       "--label", "service=#{config.healthcheck_service}",
       "-e", "KAMAL_CONTAINER_NAME=\"#{config.healthcheck_service}\"",
-      *web.env_args,
-      *web.health_check_args(cord: false),
+      *primary.env_args,
+      *primary.health_check_args(cord: false),
       *config.volume_args,
-      *web.option_args,
+      *primary.option_args,
       config.absolute_image,
-      web.cmd
+      primary.cmd
   end
 
   def status

lib/kamal/configuration.rb

@@ -91,8 +91,8 @@ def all_hosts
     roles.flat_map(&:hosts).uniq
   end
 
-  def primary_web_host
-    role(primary_web_role)&.primary_host
+  def primary_host
+    role(primary_role)&.primary_host
   end
 
   def traefik_roles
@@ -208,8 +208,8 @@ def asset_path
     raw_config.asset_path
   end
 
-  def primary_web_role
-    raw_config.primary_web_role || "web"
+  def primary_role
+    raw_config.primary_role || "web"
   end
 
   def allow_empty_roles?
@@ -225,7 +225,7 @@ def to_h
     {
       roles: role_names,
       hosts: all_hosts,
-      primary_host: primary_web_host,
+      primary_host: primary_host,
       version: version,
       repository: repository,
       absolute_image: absolute_image,
@@ -264,16 +264,12 @@ def ensure_required_keys_present
         raise ArgumentError, "You must specify a password for the registry in config/deploy.yml (or set the ENV variable if that's used)"
       end
 
-      unless role_names.include?(primary_web_role)
-        raise ArgumentError, "The primary_web_role #{primary_web_role} isn't defined"
+      unless role_names.include?(primary_role)
+        raise ArgumentError, "The primary_role #{primary_role} isn't defined"
       end
 
-      unless traefik_role_names.include?(primary_web_role)
-        raise ArgumentError, "Role #{primary_web_role} needs to have traefik enabled"
-      end
-
-      if role(primary_web_role).hosts.empty?
-        raise ArgumentError, "No servers specified for the #{primary_web_role} primary_web_role"
+      if role(primary_role).hosts.empty?
+        raise ArgumentError, "No servers specified for the #{primary_role} primary_role"
       end
 
       unless allow_empty_roles?

lib/kamal/configuration/role.rb

@@ -93,7 +93,15 @@ def health_check_interval
 
 
   def running_traefik?
-    name.web? || specializations["traefik"]
+    if specializations["traefik"].nil?
+      primary?
+    else
+      specializations["traefik"]
+    end
+  end
+
+  def primary?
+    @config.primary_role == name
   end
 
 

test/cli/healthcheck_test.rb

@@ -64,9 +64,19 @@ class CliHealthcheckTest < CliTestCase
     end
     assert_match "container not ready (unhealthy)", exception.message
   end
+
+  test "raises an exception if primary does not have traefik" do
+    SSHKit::Backend::Abstract.any_instance.expects(:execute).never
+
+    exception = assert_raises do
+      run_command("perform", config_file: "test/fixtures/deploy_workers_only.yml")
+    end
+
+    assert_equal "The primary host is not configured to run Traefik", exception.message
+  end
 
   private
-    def run_command(*command)
-      stdouted { Kamal::Cli::Healthcheck.start([*command, "-c", "test/fixtures/deploy_with_accessories.yml"]) }
+    def run_command(*command, config_file: "test/fixtures/deploy_with_accessories.yml")
+      stdouted { Kamal::Cli::Healthcheck.start([*command, "-c", config_file]) } 
     end
 end

test/cli/main_test.rb

@@ -122,6 +122,21 @@ class CliMainTest < CliTestCase
       refute_match /Running the post-deploy hook.../, output
     end
   end
+
+  test "deploy without healthcheck if primary host doesn't have traefik" do
+    invoke_options = { "config_file" => "test/fixtures/deploy_workers_only.yml", "version" => "999", "skip_hooks" => false }
+
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options).never
+
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)
+
+    run_command("deploy", config_file: "deploy_workers_only")
+  end
 
   test "deploy with missing secrets" do
     invoke_options = { "config_file" => "test/fixtures/deploy_with_secrets.yml", "version" => "999", "skip_hooks" => false }

test/configuration_test.rb

@@ -58,9 +58,9 @@ class ConfigurationTest < ActiveSupport::TestCase
     assert_equal [ "1.1.1.1", "1.1.1.2", "1.1.1.3" ], @config_with_roles.all_hosts
   end
 
-  test "primary web host" do
-    assert_equal "1.1.1.1", @config.primary_web_host
-    assert_equal "1.1.1.1", @config_with_roles.primary_web_host
+  test "primary host" do
+    assert_equal "1.1.1.1", @config.primary_host
+    assert_equal "1.1.1.1", @config_with_roles.primary_host
   end
 
   test "traefik hosts" do
@@ -289,27 +289,23 @@ class ConfigurationTest < ActiveSupport::TestCase
     assert_equal "foo", Kamal::Configuration.new(@deploy.merge!(asset_path: "foo")).asset_path
   end
 
-  test "primary web role" do
-    assert_equal "web", @config.primary_web_role
+  test "primary role" do
+    assert_equal "web", @config.primary_role
 
     config = Kamal::Configuration.new(@deploy_with_roles.deep_merge({
-      servers: { "alternate_web" => { "hosts" => [ "1.1.1.4", "1.1.1.5" ] , "traefik" => true } },
-      primary_web_role: "alternate_web" } ))
+      servers: { "alternate_web" => { "hosts" => [ "1.1.1.4", "1.1.1.5" ] } },
+      primary_role: "alternate_web" } ))
 
-    assert_equal "alternate_web", config.primary_web_role
-    assert_equal "1.1.1.4", config.primary_web_host
-  end
 
-  test "primary web role no traefik" do
-    error = assert_raises(ArgumentError) do
-      Kamal::Configuration.new(@deploy_with_roles.merge(primary_web_role: "workers"))
-    end
-    assert_match /workers needs to have traefik enabled/, error.message
+    assert_equal "alternate_web", config.primary_role
+    assert_equal "1.1.1.4", config.primary_host
+    assert config.role(:alternate_web).primary? 
+    assert config.role(:alternate_web).running_traefik?
   end
 
-  test "primary web role missing" do
+  test "primary role missing" do
     error = assert_raises(ArgumentError) do
-      Kamal::Configuration.new(@deploy.merge(primary_web_role: "bar"))
+      Kamal::Configuration.new(@deploy.merge(primary_role: "bar"))
     end
     assert_match /bar isn't defined/, error.message
   end

test/fixtures/deploy_primary_web_role_override.yml

@@ -17,4 +17,4 @@ registry:
   server: registry.digitalocean.com
   username: user
   password: pw
-primary_web_role: web_tokyo
+primary_role: web_tokyo

test/fixtures/deploy_workers_only.yml

@@ -0,0 +1,12 @@
+service: app
+image: dhh/app
+servers:
+  workers:
+    traefik: false
+    hosts:
+      - 1.1.1.1
+      - 1.1.1.2
+primary_role: workers
+registry:
+  username: user
+  password: pw