Merge pull request #946 from basecamp/kamal-2.0-downgrade

Downgrade from Kamal 2 to 1.9

lib/kamal/cli/accessory.rb

@@ -222,6 +222,25 @@ def remove_service_directory(name)
     end
   end
 
+  desc "downgrade", "Downgrade accessories from Kamal 2 to 1.9"
+  option :rolling, type: :boolean, default: false, desc: "Upgrade one host at a time"
+  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
+  def downgrade(name)
+    confirming "This will restart all accessories" do
+      with_lock do
+        host_groups = options[:rolling] ? KAMAL.accessory_hosts : [ KAMAL.accessory_hosts ]
+        host_groups.each do |hosts|
+          host_list = Array(hosts).join(",")
+          KAMAL.with_specific_hosts(hosts) do
+            say "Downgrading #{name} accessories on #{host_list}...", :magenta
+            reboot name
+            say "Downgraded #{name} accessories on #{host_list}...", :magenta
+          end
+        end
+      end
+    end
+  end
+
   private
     def with_accessory(name)
       if KAMAL.config.accessory(name)

lib/kamal/cli/base.rb

@@ -206,6 +206,10 @@ def first_invocation
         instance_variable_get("@_invocations").first
       end
 
+      def reset_invocation(cli_class)
+        instance_variable_get("@_invocations")[cli_class].pop
+      end
+
       def ensure_run_and_locks_directory
         on(KAMAL.hosts) do
           execute(*KAMAL.server.ensure_run_directory)

lib/kamal/cli/main.rb

@@ -217,6 +217,37 @@ def remove
     end
   end
 
+  desc "downgrade", "Downgrade from Kamal 2 to 1.9"
+  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
+  option :rolling, type: :boolean, default: false, desc: "Downgrade one host at a time"
+  def downgrade
+    confirming "This will replace Traefik with kamal-proxy and restart all accessories" do
+      with_lock do
+        if options[:rolling]
+          (KAMAL.hosts | KAMAL.accessory_hosts).each do |host|
+            KAMAL.with_specific_hosts(host) do
+              say "Downgrading #{host}...", :magenta
+              if KAMAL.hosts.include?(host)
+                invoke "kamal:cli:traefik:downgrade", [], options.merge(confirmed: true, rolling: false)
+                reset_invocation(Kamal::Cli::Traefik)
+              end
+              if KAMAL.accessory_hosts.include?(host)
+                invoke "kamal:cli:accessory:downgrade", [ "all" ], options.merge(confirmed: true, rolling: false)
+                reset_invocation(Kamal::Cli::Accessory)
+              end
+              say "Downgraded #{host}", :magenta
+            end
+          end
+        else
+          say "Downgrading all hosts...", :magenta
+          invoke "kamal:cli:traefik:downgrade", [], options.merge(confirmed: true)
+          invoke "kamal:cli:accessory:downgrade", [ "all" ], options.merge(confirmed: true)
+          say "Downgraded all hosts", :magenta
+        end
+      end
+    end
+  end
+
   desc "version", "Show Kamal version"
   def version
     puts Kamal::VERSION

lib/kamal/cli/traefik.rb

@@ -119,4 +119,44 @@ def remove_image
       end
     end
   end
+
+  desc "downgrade", "Downgrade to Traefik on servers (stop container, remove container, start new container, reboot app)"
+  option :rolling, type: :boolean, default: false, desc: "Reboot proxy on hosts in sequence, rather than in parallel"
+  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
+  def downgrade
+    invoke_options = { "version" => KAMAL.config.latest_tag }.merge(options)
+
+    confirming "This will cause a brief outage on each host. Are you sure?" do
+      host_groups = options[:rolling] ? KAMAL.hosts : [ KAMAL.hosts ]
+      host_groups.each do |hosts|
+        host_list = Array(hosts).join(",")
+        say "Downgrading to Traefik on #{host_list}...", :magenta
+        run_hook "pre-traefik-reboot", hosts: host_list
+        on(hosts) do |host|
+          execute *KAMAL.auditor.record("Rebooted Traefik"), verbosity: :debug
+          execute *KAMAL.registry.login
+
+          "Stopping and removing kamal-proxy on #{host}, if running..."
+          execute *KAMAL.traefik.cleanup_kamal_proxy
+
+          "Stopping and removing Traefik on #{host}, if running..."
+          execute *KAMAL.traefik.stop, raise_on_non_zero_exit: false
+          execute *KAMAL.traefik.remove_container
+          execute *KAMAL.traefik.remove_image
+        end
+
+        KAMAL.with_specific_hosts(hosts) do
+          invoke "kamal:cli:traefik:boot", [], invoke_options
+          reset_invocation(Kamal::Cli::Traefik)
+          invoke "kamal:cli:app:boot", [], invoke_options
+          reset_invocation(Kamal::Cli::App)
+          invoke "kamal:cli:prune:all", [], invoke_options
+          reset_invocation(Kamal::Cli::Prune)
+        end
+
+        run_hook "post-traefik-reboot", hosts: host_list
+        say "Downgraded to Traefik on #{host_list}", :magenta
+      end
+    end
+  end
 end

lib/kamal/commander.rb

@@ -56,6 +56,13 @@ def specific_hosts=(hosts)
     end
   end
 
+  def with_specific_hosts(hosts)
+    original_hosts, self.specific_hosts = specific_hosts, hosts
+    yield
+  ensure
+    self.specific_hosts = original_hosts
+  end
+
   def accessory_names
     config.accessories&.collect(&:name) || []
   end

lib/kamal/commander/specifics.rb

@@ -23,7 +23,7 @@ def traefik_hosts
   end
 
   def accessory_hosts
-    specific_hosts || config.accessories.flat_map(&:hosts)
+    config.accessories.flat_map(&:hosts) & specified_hosts
   end
 
   private

lib/kamal/commands/traefik.rb

@@ -62,6 +62,15 @@ def remove_env_file
     [ :rm, "-f", env.secrets_file ]
   end
 
+  def cleanup_kamal_proxy
+    chain \
+      docker(:container, :stop, "kamal-proxy"),
+      combine(
+        docker(:container, :prune, "--force", "--filter", "label=org.opencontainers.image.title=kamal-proxy"),
+        docker(:image, :prune, "--all", "--force", "--filter", "label=org.opencontainers.image.title=kamal-proxy")
+      )
+  end
+
   private
     def publish_args
       argumentize "--publish", port if publish?

test/cli/accessory_test.rb

@@ -209,6 +209,24 @@ class CliAccessoryTest < CliTestCase
     end
   end
 
+  test "downgrade" do
+    run_command("downgrade", "-y", "all").tap do |output|
+      assert_match "Downgrading all accessories on 1.1.1.3,1.1.1.1,1.1.1.2...", output
+      assert_match "docker container stop app-mysql on 1.1.1.3", output
+      assert_match "docker run --name app-mysql --detach --restart unless-stopped --log-opt max-size=\"10m\" --publish 3306:3306 --env-file .kamal/env/accessories/app-mysql.env --env MYSQL_ROOT_HOST=\"%\" --volume $PWD/app-mysql/etc/mysql/my.cnf:/etc/mysql/my.cnf --volume $PWD/app-mysql/data:/var/lib/mysql --label service=\"app-mysql\" mysql:5.7 on 1.1.1.3", output
+      assert_match "Downgraded all accessories on 1.1.1.3,1.1.1.1,1.1.1.2", output
+    end
+  end
+
+  test "downgrade rolling" do
+    run_command("downgrade", "--rolling", "-y", "all").tap do |output|
+      assert_match "Downgrading all accessories on 1.1.1.3...", output
+      assert_match "docker container stop app-mysql on 1.1.1.3", output
+      assert_match "docker run --name app-mysql --detach --restart unless-stopped --log-opt max-size=\"10m\" --publish 3306:3306 --env-file .kamal/env/accessories/app-mysql.env --env MYSQL_ROOT_HOST=\"%\" --volume $PWD/app-mysql/etc/mysql/my.cnf:/etc/mysql/my.cnf --volume $PWD/app-mysql/data:/var/lib/mysql --label service=\"app-mysql\" mysql:5.7 on 1.1.1.3", output
+      assert_match "Downgraded all accessories on 1.1.1.3", output
+    end
+  end
+
   private
     def run_command(*command)
       stdouted { Kamal::Cli::Accessory.start([ *command, "-c", "test/fixtures/deploy_with_accessories.yml" ]) }

test/cli/main_test.rb

@@ -537,6 +537,34 @@ class CliMainTest < CliTestCase
     assert_equal Kamal::VERSION, version
   end
 
+  test "downgrade" do
+    invoke_options = { "config_file" => "test/fixtures/deploy_with_accessories.yml", "skip_hooks" => false, "confirmed" => true, "rolling" => false }
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:downgrade", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:downgrade", [ "all" ], invoke_options)
+
+    run_command("downgrade", "-y", config_file: "deploy_with_accessories").tap do |output|
+      assert_match "Downgrading all hosts...", output
+      assert_match "Downgraded all hosts", output
+    end
+  end
+
+  test "downgrade rolling" do
+    invoke_options = { "config_file" => "test/fixtures/deploy_with_accessories.yml", "skip_hooks" => false, "confirmed" => true, "rolling" => false }
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:downgrade", [], invoke_options).times(4)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:downgrade", [ "all" ], invoke_options).times(3)
+
+    run_command("downgrade", "--rolling", "-y", config_file: "deploy_with_accessories").tap do |output|
+      assert_match "Downgrading 1.1.1.1...", output
+      assert_match "Downgraded 1.1.1.1", output
+      assert_match "Downgrading 1.1.1.2...", output
+      assert_match "Downgraded 1.1.1.2", output
+      assert_match "Downgrading 1.1.1.3...", output
+      assert_match "Downgraded 1.1.1.3", output
+      assert_match "Downgrading 1.1.1.4...", output
+      assert_match "Downgraded 1.1.1.4", output
+    end
+  end
+
   private
     def run_command(*command, config_file: "deploy_simple")
       stdouted { Kamal::Cli::Main.start([ *command, "-c", "test/fixtures/#{config_file}.yml" ]) }

test/cli/traefik_test.rb

@@ -103,6 +103,90 @@ class CliTraefikTest < CliTestCase
     end
   end
 
+  test "downgrade" do
+    Object.any_instance.stubs(:sleep)
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", raise_on_non_zero_exit: false)
+      .returns("12345678")
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-workers-latest$", "--quiet", raise_on_non_zero_exit: false)
+      .returns("12345678")
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with { |*args| args[0..1] == [ :sh, "-c" ] }
+      .returns("123") # old version
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
+      .returns("running") # health check
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-workers-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
+      .returns("running").at_least_once # workers health check
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :inspect, "-f '{{ range .Mounts }}{{printf \"%s %s\\n\" .Source .Destination}}{{ end }}'", "app-web-123", "|", :awk, "'$2 == \"/tmp/kamal-cord\" {print $1}'", raise_on_non_zero_exit: false)
+      .returns("") # old version
+
+    run_command("downgrade", "-y").tap do |output|
+      assert_match "Downgrading to Traefik on 1.1.1.1,1.1.1.2,1.1.1.3,1.1.1.4...", output
+      assert_match "docker login -u [REDACTED] -p [REDACTED]", output
+      assert_match "docker container stop kamal-proxy ; docker container prune --force --filter label=org.opencontainers.image.title=kamal-proxy && docker image prune --all --force --filter label=org.opencontainers.image.title=kamal-proxy", 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 image prune --all --force --filter label=org.opencontainers.image.title=Traefik", output
+      assert_match "/usr/bin/env mkdir -p .kamal", output
+      assert_match "docker login -u [REDACTED] -p [REDACTED]", output
+      assert_match "docker container start traefik || docker run --name traefik --detach --restart unless-stopped --publish 80:80 --volume /var/run/docker.sock:/var/run/docker.sock --env-file .kamal/env/traefik/traefik.env --log-opt max-size=\"10m\" --label traefik.http.routers.catchall.entryPoints=\"http\" --label traefik.http.routers.catchall.rule=\"PathPrefix(\\`/\\`)\" --label traefik.http.routers.catchall.service=\"unavailable\" --label traefik.http.routers.catchall.priority=\"1\" --label traefik.http.services.unavailable.loadbalancer.server.port=\"0\" traefik:v2.10 --providers.docker --log.level=\"DEBUG\"", output
+      assert_match "/usr/bin/env mkdir -p .kamal", output
+      assert_match %r{docker rename app-web-latest app-web-latest_replaced_.*}, output
+      assert_match %r{docker run --detach --restart unless-stopped --name app-web-latest --hostname 1.1.1.1-.* -e KAMAL_CONTAINER_NAME="app-web-latest" -e KAMAL_VERSION="latest" --env-file .kamal/env/roles/app-web.env --health-cmd}, output
+      assert_match "docker tag dhh/app:latest dhh/app:latest", output
+      assert_match "/usr/bin/env mkdir -p .kamal", output
+      assert_match "docker ps -q -a --filter label=service=app --filter status=created --filter status=exited --filter status=dead | tail -n +6 | while read container_id; do docker rm $container_id; done", output
+      assert_match "docker image prune --force --filter label=service=app", output
+      assert_match "Downgraded to Traefik on 1.1.1.1,1.1.1.2,1.1.1.3,1.1.1.4", output
+    end
+  end
+
+  test "downgrade rolling" do
+    Object.any_instance.stubs(:sleep)
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", raise_on_non_zero_exit: false)
+      .returns("12345678")
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-workers-latest$", "--quiet", raise_on_non_zero_exit: false)
+      .returns("12345678")
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with { |*args| args[0..1] == [ :sh, "-c" ] }
+      .returns("123") # old version
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
+      .returns("running") # health check
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-workers-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
+      .returns("running").at_least_once # workers health check
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :inspect, "-f '{{ range .Mounts }}{{printf \"%s %s\\n\" .Source .Destination}}{{ end }}'", "app-web-123", "|", :awk, "'$2 == \"/tmp/kamal-cord\" {print $1}'", raise_on_non_zero_exit: false)
+      .returns("") # old version
+
+    run_command("downgrade", "--rolling", "-y",).tap do |output|
+      %w[1.1.1.1 1.1.1.2 1.1.1.3 1.1.1.4].each do |host|
+        assert_match "Downgrading to Traefik on #{host}...", output
+        assert_match "docker container stop kamal-proxy ; docker container prune --force --filter label=org.opencontainers.image.title=kamal-proxy && docker image prune --all --force --filter label=org.opencontainers.image.title=kamal-proxy", output
+        assert_match "Downgraded to Traefik on #{host}", output
+      end
+    end
+  end
+
   private
     def run_command(*command)
       stdouted { Kamal::Cli::Traefik.start([ *command, "-c", "test/fixtures/deploy_with_accessories.yml" ]) }