Work out the host and port for the container

Avoid docker inspect:
1. Use the container ID as the host
2. Configure the port, default to 3000

lib/kamal/cli/app.rb

@@ -44,7 +44,7 @@ class Kamal::Cli::App < Kamal::Cli::Base
 
           if role.running_traefik? && KAMAL.proxy_host?(host)
             version = capture_with_info(*app.current_running_version, raise_on_non_zero_exit: false).strip
-            endpoint = capture_with_info(*app.container_endpoint(version: version)).strip
+            endpoint = capture_with_info(*app.container_id_for_version(version)).strip
             raise Kamal::Cli::BootError, "Failed to get endpoint for #{role} on #{host}, did the container boot?" if endpoint.empty?
 
             execute *KAMAL.proxy.deploy(role.container_prefix, target: endpoint)
@@ -66,7 +66,7 @@ class Kamal::Cli::App < Kamal::Cli::Base
 
           if role.running_traefik? && KAMAL.proxy_host?(host)
             version = capture_with_info(*app.current_running_version, raise_on_non_zero_exit: false).strip
-            endpoint = capture_with_info(*app.container_endpoint(version: version)).strip
+            endpoint = capture_with_info(*app.container_id_for_version(version)).strip
             if endpoint.present?
               execute *KAMAL.proxy.remove(role.container_prefix, target: endpoint), raise_on_non_zero_exit: false
             end

lib/kamal/cli/app/boot.rb

@@ -53,7 +53,7 @@ class Kamal::Cli::App::Boot
       if proxy_host?
         execute *app.run_for_proxy(hostname: hostname)
         if running_traefik?
-          endpoint = capture_with_info(*app.container_endpoint(version: version)).strip
+          endpoint = capture_with_info(*app.container_id_for_version(version)).strip
           raise Kamal::Cli::BootError, "Failed to get endpoint for #{role} on #{host}, did the container boot?" if endpoint.empty?
           execute *KAMAL.proxy.deploy(role.container_prefix, target: endpoint)
         else

lib/kamal/cli/proxy.rb

@@ -52,7 +52,7 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
                 app = KAMAL.app(role: role, host: host)
 
                 version = capture_with_info(*app.current_running_version, raise_on_non_zero_exit: false).strip
-                endpoint = capture_with_info(*app.container_endpoint(version: version)).strip
+                endpoint = capture_with_info(*app.container_id_for_version(version)).strip
 
                 if endpoint.present?
                   info "Deploying #{endpoint} for role `#{role}` on #{host}..."

lib/kamal/commands/app/containers.rb

@@ -28,11 +28,4 @@ module Kamal::Commands::App::Containers
       container_id_for(container_name: container_name(version)),
       xargs(docker(:inspect, "--format", DOCKER_HEALTH_LOG_FORMAT))
   end
-
-  def container_endpoint(version:)
-    pipe \
-      container_id_for(container_name: container_name(version)),
-      xargs(docker(:inspect, "--format", "'{{index .NetworkSettings.Networks.kamal.Aliases 0}}{{range $k, $v := .NetworkSettings.Ports}}{{printf \":%s\" $k}}{{break}}{{end}}'")),
-      [ :sed, "-e", "'s/\\/tcp$//'" ]
-  end
 end

lib/kamal/commands/proxy.rb

@@ -1,6 +1,6 @@
 class Kamal::Commands::Proxy < Kamal::Commands::Base
   delegate :argumentize, :optionize, to: Kamal::Utils
-  delegate :container_name, to: :proxy_config
+  delegate :container_name, :port, to: :proxy_config
 
   attr_reader :proxy_config
 
@@ -35,11 +35,11 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
   end
 
   def deploy(service, target:)
-    docker :exec, container_name, "kamal-proxy", :deploy, service, *optionize({ target: target }), *proxy_config.deploy_command_args
+    docker :exec, container_name, "kamal-proxy", :deploy, service, *optionize({ target: "#{target}:#{port}" }), *proxy_config.deploy_command_args
   end
 
   def remove(service, target:)
-    docker :exec, container_name, "kamal-proxy", :remove, service, *optionize({ target: target })
+    docker :exec, container_name, "kamal-proxy", :remove, service, *optionize({ target: "#{target}:#{port}" })
   end
 
   def info

lib/kamal/configuration/docs/proxy.yml

@@ -56,6 +56,12 @@ proxy:
   # requests for other apps that do have a host set.
   host: foo.example.com
 
+  # Port
+  #
+  # The port the application is exposed on
+  # Defaults to 80
+  port: 3000
+
   # SSL
   #
   # Kamal Proxy can automatically obtain and renew TLS certificates for your applications.

lib/kamal/configuration/proxy.rb

@@ -25,6 +25,10 @@ class Kamal::Configuration::Proxy
     end
   end
 
+  def port
+    proxy_config.fetch("port", 80)
+  end
+
   def image
     proxy_config.fetch("image", DEFAULT_IMAGE)
   end