From 1ea5d0bd8664f1e8697d745d4d6bf05dfa27df3d Mon Sep 17 00:00:00 2001
From: Donal McBreen <donal@37signals.com>
Date: Thu, 17 Apr 2025 14:44:19 +0100
Subject: [PATCH 1/3] Allow kamal-proxy run command options to be set

Allow --metrics_port and --debug options to be set via the boot config.

--metrics_port support will come in kamal-proxy v0.8.8, so this option
doesn't work right now.

This will be updated before the next Kamal release though and we can add
integration tests for the metrics at that point.
---
 lib/kamal/cli/proxy.rb                        | 12 ++++++
 lib/kamal/commands/proxy.rb                   | 10 ++++-
 test/cli/proxy_test.rb                        | 40 ++++++++++++++-----
 test/commands/proxy_test.rb                   | 16 +++++++-
 .../.kamal/hooks/pre-deploy                   |  4 ++
 5 files changed, 70 insertions(+), 12 deletions(-)
 create mode 100755 test/integration/docker/deployer/app_with_proxied_accessory/.kamal/hooks/pre-deploy

diff --git a/lib/kamal/cli/proxy.rb b/lib/kamal/cli/proxy.rb
index cd4e45d9..91bcdfc1 100644
--- a/lib/kamal/cli/proxy.rb
+++ b/lib/kamal/cli/proxy.rb
@@ -31,6 +31,8 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
   option :registry, type: :string, default: nil, desc: "Registry to use for the proxy image"
   option :repository, type: :string, default: nil, desc: "Repository for the proxy image"
   option :image_version, type: :string, default: nil, desc: "Version of the proxy to run"
+  option :metrics_port, type: :numeric, default: nil, desc: "Port to report prometheus metrics on"
+  option :debug, type: :boolean, default: false, desc: "Whether to run the proxy in debug mode"
   option :docker_options, type: :array, default: [], desc: "Docker options to pass to the proxy container", banner: "option=value option2=value2"
   def boot_config(subcommand)
     proxy_boot_config = KAMAL.config.proxy_boot
@@ -51,6 +53,9 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
 
       image_version = options[:image_version]
 
+      run_command_options = { debug: options[:debug] || nil, "metrics-port": options[:metrics_port] }.compact
+      run_command = "kamal-proxy run #{Kamal::Utils.optionize(run_command_options).join(" ")}" if run_command_options.any?
+
       on(KAMAL.proxy_hosts) do |host|
         execute(*KAMAL.proxy.ensure_proxy_directory)
         if boot_options != proxy_boot_config.default_boot_options
@@ -70,6 +75,12 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
         else
           execute *KAMAL.proxy.reset_image_version, raise_on_non_zero_exit: false
         end
+
+        if run_command
+          upload! StringIO.new(run_command), KAMAL.config.proxy_run_command_file
+        else
+          execute *KAMAL.proxy.reset_run_command, raise_on_non_zero_exit: false
+        end
       end
     when "get"
 
@@ -81,6 +92,7 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
         execute *KAMAL.proxy.reset_boot_options, raise_on_non_zero_exit: false
         execute *KAMAL.proxy.reset_image, raise_on_non_zero_exit: false
         execute *KAMAL.proxy.reset_image_version, raise_on_non_zero_exit: false
+        execute *KAMAL.proxy.reset_run_command, raise_on_non_zero_exit: false
       end
     else
       raise ArgumentError, "Unknown boot_config subcommand #{subcommand}"
diff --git a/lib/kamal/commands/proxy.rb b/lib/kamal/commands/proxy.rb
index 2193fff7..b9b255f5 100644
--- a/lib/kamal/commands/proxy.rb
+++ b/lib/kamal/commands/proxy.rb
@@ -70,7 +70,7 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
   end
 
   def boot_config
-    [ :echo, "#{substitute(read_boot_options)} #{substitute(read_image)}:#{substitute(read_image_version)}" ]
+    [ :echo, "#{substitute(read_boot_options)} #{substitute(read_image)}:#{substitute(read_image_version)} #{substitute(read_run_command)}" ]
   end
 
   def read_boot_options
@@ -85,6 +85,10 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
     read_file(config.proxy_boot.image_version_file, default: Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION)
   end
 
+  def read_run_command
+    read_file(config.proxy_run_command_file)
+  end
+
   def reset_boot_options
     remove_file config.proxy_boot.options_file
   end
@@ -97,6 +101,10 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
     remove_file config.proxy_boot.image_version_file
   end
 
+  def reset_run_command
+    remove_file config.proxy_run_command_file
+  end
+
   private
     def container_name
       config.proxy_boot.container_name
diff --git a/test/cli/proxy_test.rb b/test/cli/proxy_test.rb
index 428fc515..fea95406 100644
--- a/test/cli/proxy_test.rb
+++ b/test/cli/proxy_test.rb
@@ -5,7 +5,7 @@ class CliProxyTest < CliTestCase
     run_command("boot").tap do |output|
       assert_match "docker login", output
       assert_match "mkdir -p .kamal/proxy/apps-config", output
-      assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
+      assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
     end
   end
 
@@ -19,7 +19,7 @@ class CliProxyTest < CliTestCase
     exception = assert_raises do
       run_command("boot").tap do |output|
         assert_match "docker login", output
-        assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
+        assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
       end
     end
 
@@ -37,7 +37,7 @@ class CliProxyTest < CliTestCase
 
     run_command("boot").tap do |output|
       assert_match "docker login", output
-      assert_match "docker container start kamal-proxy || echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
+      assert_match "docker container start kamal-proxy || echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
     end
   ensure
     Thread.report_on_exception = false
@@ -58,13 +58,13 @@ class CliProxyTest < CliTestCase
       assert_match "docker container stop kamal-proxy on 1.1.1.1", output
       assert_match "docker container prune --force --filter label=org.opencontainers.image.title=kamal-proxy on 1.1.1.1", output
       assert_match "mkdir -p .kamal/proxy/apps-config on 1.1.1.1", output
-      assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config on 1.1.1.1", output
+      assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config on 1.1.1.1", output
       assert_match "docker exec kamal-proxy kamal-proxy deploy app-web --target=\"abcdefabcdef:80\" --deploy-timeout=\"6s\" --drain-timeout=\"30s\" --buffer-requests --buffer-responses --log-request-header=\"Cache-Control\" --log-request-header=\"Last-Modified\" --log-request-header=\"User-Agent\" on 1.1.1.1", output
 
       assert_match "docker container stop kamal-proxy on 1.1.1.2", output
       assert_match "docker container prune --force --filter label=org.opencontainers.image.title=kamal-proxy on 1.1.1.2", output
       assert_match "mkdir -p .kamal/proxy/apps-config on 1.1.1.1", output
-      assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config on 1.1.1.2", output
+      assert_match "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config on 1.1.1.2", output
       assert_match "docker exec kamal-proxy kamal-proxy deploy app-web --target=\"abcdefabcdef:80\" --deploy-timeout=\"6s\" --drain-timeout=\"30s\" --buffer-requests --buffer-responses --log-request-header=\"Cache-Control\" --log-request-header=\"Last-Modified\" --log-request-header=\"User-Agent\" on 1.1.1.2", output
     end
   end
@@ -199,7 +199,7 @@ class CliProxyTest < CliTestCase
       assert_match "/usr/bin/env mkdir -p .kamal", output
       assert_match "docker network create kamal", output
       assert_match "docker login -u [REDACTED] -p [REDACTED]", output
-      assert_match "docker container start kamal-proxy || echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", output
+      assert_match "docker container start kamal-proxy || echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy", 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 "/usr/bin/env mkdir -p .kamal/apps/app/env/roles", output
@@ -243,7 +243,9 @@ class CliProxyTest < CliTestCase
         assert_match "Running /usr/bin/env mkdir -p .kamal/proxy on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
-        assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output      end
+        assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
+      end
     end
   end
 
@@ -254,6 +256,7 @@ class CliProxyTest < CliTestCase
         assert_match "Uploading \"--log-opt max-size=10m\" to .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
       end
     end
   end
@@ -265,6 +268,7 @@ class CliProxyTest < CliTestCase
         assert_match "Uploading \"--publish 80:80 --publish 443:443 --log-opt max-size=100m\" to .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
       end
     end
   end
@@ -276,6 +280,7 @@ class CliProxyTest < CliTestCase
         assert_match "Uploading \"--publish 80:80 --publish 443:443\" to .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
       end
     end
   end
@@ -322,6 +327,7 @@ class CliProxyTest < CliTestCase
         assert_match "Uploading \"--publish 80:80 --publish 443:443 --log-opt max-size=10m --label=foo=bar --add_host=thishost:thathost\" to .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
       end
     end
   end
@@ -333,6 +339,7 @@ class CliProxyTest < CliTestCase
         assert_match "Running /usr/bin/env rm .kamal/proxy/options on #{host}", output
         assert_match "Uploading \"myreg/basecamp/kamal-proxy\" to .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
       end
     end
   end
@@ -344,6 +351,7 @@ class CliProxyTest < CliTestCase
         assert_match "Running /usr/bin/env rm .kamal/proxy/options on #{host}", output
         assert_match "Uploading \"myrepo/kamal-proxy\" to .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
       end
     end
   end
@@ -355,23 +363,37 @@ class CliProxyTest < CliTestCase
         assert_match "Running /usr/bin/env rm .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
         assert_match "Uploading \"0.9.9\" to .kamal/proxy/image_version on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/run_command on #{host}", output
+      end
+    end
+  end
+
+  test "boot_config set run_command" do
+    run_command("boot_config", "set", "--metrics_port", "9000", "--debug", "true").tap do |output|
+      %w[ 1.1.1.1 1.1.1.2 ].each do |host|
+        assert_match "Running /usr/bin/env mkdir -p .kamal/proxy on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/options on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
+        assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
+        assert_match "Uploading \"kamal-proxy run --debug --metrics-port \\\"9000\\\"\" to .kamal/proxy/run_command on #{host}", output
       end
     end
   end
 
   test "boot_config set all" do
-    run_command("boot_config", "set", "--docker_options", "label=foo=bar", "--registry", "myreg", "--repository", "myrepo", "--image_version", "0.9.9").tap do |output|
+    run_command("boot_config", "set", "--docker_options", "label=foo=bar", "--registry", "myreg", "--repository", "myrepo", "--image_version", "0.9.9", "--metrics_port", "9000", "--debug", "true").tap do |output|
       %w[ 1.1.1.1 1.1.1.2 ].each do |host|
         assert_match "Uploading \"--publish 80:80 --publish 443:443 --log-opt max-size=10m --label=foo=bar\" to .kamal/proxy/options on #{host}", output
         assert_match "Uploading \"myreg/myrepo/kamal-proxy\" to .kamal/proxy/image on #{host}", output
         assert_match "Uploading \"0.9.9\" to .kamal/proxy/image_version on #{host}", output
+        assert_match "Uploading \"kamal-proxy run --debug --metrics-port \\\"9000\\\"\" to .kamal/proxy/run_command on #{host}", output
       end
     end
   end
 
   test "boot_config get" do
     SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:echo, "$(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"v0.8.7\")")
+      .with(:echo, "$(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\")")
       .returns("--publish 80:80 --publish 8443:443 --label=foo=bar basecamp/kamal-proxy:v1.0.0")
       .twice
 
diff --git a/test/commands/proxy_test.rb b/test/commands/proxy_test.rb
index e141725a..2bb2dadb 100644
--- a/test/commands/proxy_test.rb
+++ b/test/commands/proxy_test.rb
@@ -15,7 +15,7 @@ class CommandsProxyTest < ActiveSupport::TestCase
 
   test "run" do
     assert_equal \
-      "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config",
+      "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config",
       new_command.run.join(" ")
   end
 
@@ -23,7 +23,7 @@ class CommandsProxyTest < ActiveSupport::TestCase
     @config.delete(:proxy)
 
     assert_equal \
-      "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config",
+      "echo $(cat .kamal/proxy/options 2> /dev/null || echo \"--publish 80:80 --publish 443:443 --log-opt max-size=10m\") $(cat .kamal/proxy/image 2> /dev/null || echo \"basecamp/kamal-proxy\"):$(cat .kamal/proxy/image_version 2> /dev/null || echo \"#{Kamal::Configuration::Proxy::Boot::MINIMUM_VERSION}\") $(cat .kamal/proxy/run_command 2> /dev/null || echo \"\") | xargs docker run --name kamal-proxy --network kamal --detach --restart unless-stopped --volume kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy --volume $(pwd)/.kamal/proxy/apps-config:/home/kamal-proxy/.apps-config",
       new_command.run.join(" ")
   end
 
@@ -129,6 +129,12 @@ class CommandsProxyTest < ActiveSupport::TestCase
       new_command.read_image_version.join(" ")
   end
 
+  test "read_run_command" do
+    assert_equal \
+      "cat .kamal/proxy/run_command 2> /dev/null || echo \"\"",
+      new_command.read_run_command.join(" ")
+  end
+
   test "reset_boot_options" do
     assert_equal \
       "rm .kamal/proxy/options",
@@ -153,6 +159,12 @@ class CommandsProxyTest < ActiveSupport::TestCase
       new_command.ensure_apps_config_directory.join(" ")
   end
 
+  test "reset_run_command" do
+    assert_equal \
+      "rm .kamal/proxy/run_command",
+      new_command.reset_run_command.join(" ")
+  end
+
   private
     def new_command
       Kamal::Commands::Proxy.new(Kamal::Configuration.new(@config, version: "123"))
diff --git a/test/integration/docker/deployer/app_with_proxied_accessory/.kamal/hooks/pre-deploy b/test/integration/docker/deployer/app_with_proxied_accessory/.kamal/hooks/pre-deploy
new file mode 100755
index 00000000..af8d0b4a
--- /dev/null
+++ b/test/integration/docker/deployer/app_with_proxied_accessory/.kamal/hooks/pre-deploy
@@ -0,0 +1,4 @@
+#!/bin/sh
+set -e
+
+kamal proxy boot_config set --registry registry:4443

From e32ea2e2764ca88a6127d71fafc14ad65f643ace Mon Sep 17 00:00:00 2001
From: Donal McBreen <donal@37signals.com>
Date: Thu, 17 Apr 2025 16:09:01 +0100
Subject: [PATCH 2/3] Expose the metrics port

---
 lib/kamal/cli/proxy.rb | 1 +
 test/cli/proxy_test.rb | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/kamal/cli/proxy.rb b/lib/kamal/cli/proxy.rb
index 91bcdfc1..a65caf52 100644
--- a/lib/kamal/cli/proxy.rb
+++ b/lib/kamal/cli/proxy.rb
@@ -42,6 +42,7 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
       boot_options = [
         *(proxy_boot_config.publish_args(options[:http_port], options[:https_port], options[:publish_host_ip]) if options[:publish]),
         *(proxy_boot_config.logging_args(options[:log_max_size])),
+        *("--expose=#{options[:metrics_port]}" if options[:metrics_port]),
         *options[:docker_options].map { |option| "--#{option}" }
       ]
 
diff --git a/test/cli/proxy_test.rb b/test/cli/proxy_test.rb
index fea95406..fd131984 100644
--- a/test/cli/proxy_test.rb
+++ b/test/cli/proxy_test.rb
@@ -372,7 +372,7 @@ class CliProxyTest < CliTestCase
     run_command("boot_config", "set", "--metrics_port", "9000", "--debug", "true").tap do |output|
       %w[ 1.1.1.1 1.1.1.2 ].each do |host|
         assert_match "Running /usr/bin/env mkdir -p .kamal/proxy on #{host}", output
-        assert_match "Running /usr/bin/env rm .kamal/proxy/options on #{host}", output
+        assert_match "Uploading \"--publish 80:80 --publish 443:443 --log-opt max-size=10m --expose=9000\" to .kamal/proxy/options on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image on #{host}", output
         assert_match "Running /usr/bin/env rm .kamal/proxy/image_version on #{host}", output
         assert_match "Uploading \"kamal-proxy run --debug --metrics-port \\\"9000\\\"\" to .kamal/proxy/run_command on #{host}", output
@@ -383,7 +383,7 @@ class CliProxyTest < CliTestCase
   test "boot_config set all" do
     run_command("boot_config", "set", "--docker_options", "label=foo=bar", "--registry", "myreg", "--repository", "myrepo", "--image_version", "0.9.9", "--metrics_port", "9000", "--debug", "true").tap do |output|
       %w[ 1.1.1.1 1.1.1.2 ].each do |host|
-        assert_match "Uploading \"--publish 80:80 --publish 443:443 --log-opt max-size=10m --label=foo=bar\" to .kamal/proxy/options on #{host}", output
+        assert_match "Uploading \"--publish 80:80 --publish 443:443 --log-opt max-size=10m --expose=9000 --label=foo=bar\" to .kamal/proxy/options on #{host}", output
         assert_match "Uploading \"myreg/myrepo/kamal-proxy\" to .kamal/proxy/image on #{host}", output
         assert_match "Uploading \"0.9.9\" to .kamal/proxy/image_version on #{host}", output
         assert_match "Uploading \"kamal-proxy run --debug --metrics-port \\\"9000\\\"\" to .kamal/proxy/run_command on #{host}", output

From 226e7091dbe196260868459cc73758473bd7650d Mon Sep 17 00:00:00 2001
From: Donal McBreen <donal@37signals.com>
Date: Tue, 6 May 2025 12:14:58 +0100
Subject: [PATCH 3/3] Add run_command_file to proxy boot

---
 lib/kamal/cli/proxy.rb                | 2 +-
 lib/kamal/commands/proxy.rb           | 4 ++--
 lib/kamal/configuration/proxy/boot.rb | 4 ++++
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/kamal/cli/proxy.rb b/lib/kamal/cli/proxy.rb
index a65caf52..73707572 100644
--- a/lib/kamal/cli/proxy.rb
+++ b/lib/kamal/cli/proxy.rb
@@ -78,7 +78,7 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
         end
 
         if run_command
-          upload! StringIO.new(run_command), KAMAL.config.proxy_run_command_file
+          upload! StringIO.new(run_command), proxy_boot_config.run_command_file
         else
           execute *KAMAL.proxy.reset_run_command, raise_on_non_zero_exit: false
         end
diff --git a/lib/kamal/commands/proxy.rb b/lib/kamal/commands/proxy.rb
index b9b255f5..7699dde2 100644
--- a/lib/kamal/commands/proxy.rb
+++ b/lib/kamal/commands/proxy.rb
@@ -86,7 +86,7 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
   end
 
   def read_run_command
-    read_file(config.proxy_run_command_file)
+    read_file(config.proxy_boot.run_command_file)
   end
 
   def reset_boot_options
@@ -102,7 +102,7 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
   end
 
   def reset_run_command
-    remove_file config.proxy_run_command_file
+    remove_file config.proxy_boot.run_command_file
   end
 
   private
diff --git a/lib/kamal/configuration/proxy/boot.rb b/lib/kamal/configuration/proxy/boot.rb
index 668c0cea..9f8c6f5c 100644
--- a/lib/kamal/configuration/proxy/boot.rb
+++ b/lib/kamal/configuration/proxy/boot.rb
@@ -66,6 +66,10 @@ class Kamal::Configuration::Proxy::Boot
     File.join host_directory, "image_version"
   end
 
+  def run_command_file
+    File.join host_directory, "run_command"
+  end
+
   def apps_directory
     File.join host_directory, "apps-config"
   end