Merge pull request basecamp#393 from basecamp/rolling-traefik-restarts

Support a --rolling option for traefik reboots

README.md

@@ -633,6 +633,16 @@ traefik:
     entrypoints.otherentrypoint.address: ':9000'
 ```
 
+### Rebooting Traefik
+
+If you make changes to Traefik args or labels, you'll need to reboot with:
+
+`mrsk traefik reboot`
+
+In production, reboot the Traefik containers one by one with a slower but safer approach, using a rolling reboot:
+
+`mrsk traefik reboot --rolling`
+
 ### Configuring build args for new images
 
 Build arguments that aren't secret can also be configured:

lib/mrsk/cli/traefik.rb

@@ -1,24 +1,25 @@
 class Mrsk::Cli::Traefik < Mrsk::Cli::Base
   desc "boot", "Boot Traefik on servers"
-  def boot(login: true)
+  def boot
     mutating do
       on(MRSK.traefik_hosts) do
-        execute *MRSK.registry.login if login
+        execute *MRSK.registry.login
         execute *MRSK.traefik.run, raise_on_non_zero_exit: false
       end
     end
   end
 
   desc "reboot", "Reboot Traefik on servers (stop container, remove container, start new container)"
+  option :rolling, type: :boolean, default: false, desc: "Reboot traefik on hosts in sequence, rather than in parallel"
   def reboot
     mutating do
-      on(MRSK.traefik_hosts) do
+      on(MRSK.traefik_hosts, in: options[:rolling] ? :sequence : :parallel) do
+        execute *MRSK.auditor.record("Rebooted traefik"), verbosity: :debug
         execute *MRSK.registry.login
+        execute *MRSK.traefik.stop, raise_on_non_zero_exit: false
+        execute *MRSK.traefik.remove_container
+        execute *MRSK.traefik.run, raise_on_non_zero_exit: false
       end
-
-      stop
-      remove_container
-      boot(login: false)
     end
   end
 

test/cli/traefik_test.rb

@@ -10,11 +10,18 @@ class CliTraefikTest < CliTestCase
 
   test "reboot" do
     Mrsk::Commands::Registry.any_instance.expects(:login).twice
-    Mrsk::Cli::Traefik.any_instance.expects(:stop)
-    Mrsk::Cli::Traefik.any_instance.expects(:remove_container)
-    Mrsk::Cli::Traefik.any_instance.expects(:boot).with(login: false)
 
-    run_command("reboot")
+    run_command("reboot").tap do |output|
+      assert_match "docker container stop traefik", output
+      assert_match "docker container prune --force --filter label=org.opencontainers.image.title=Traefik", output
+      assert_match "docker run --name traefik --detach --restart unless-stopped --publish 80:80 --volume /var/run/docker.sock:/var/run/docker.sock --log-opt max-size=\"10m\" #{Mrsk::Commands::Traefik::DEFAULT_IMAGE} --providers.docker --log.level=\"DEBUG\"", output
+    end
+  end
+
+  test "reboot --rolling" do
+    run_command("reboot", "--rolling").tap do |output|
+      assert_match "Running docker container prune --force --filter label=org.opencontainers.image.title=Traefik on 1.1.1.1", output.lines[3]
+    end
   end
 
   test "start" do