Add support for multiple publish ip addresses

lib/kamal/cli/proxy.rb

@@ -23,7 +23,7 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
 
   desc "boot_config <set|get|reset>", "Manage kamal-proxy boot configuration"
   option :publish, type: :boolean, default: true, desc: "Publish the proxy ports on the host"
-  option :publish_host_ip, type: :string, desc: "Host IP address to bind HTTP/HTTPS traffic to. Defaults to all interfaces"
+  option :publish_host_ip, type: :string, repeatable: true, default: nil, desc: "Host IP address to bind HTTP/HTTPS traffic to. Defaults to all interfaces"
   option :http_port, type: :numeric, default: Kamal::Configuration::PROXY_HTTP_PORT, desc: "HTTP port to publish on the host"
   option :https_port, type: :numeric, default: Kamal::Configuration::PROXY_HTTPS_PORT, desc: "HTTPS port to publish on the host"
   option :log_max_size, type: :string, default: Kamal::Configuration::PROXY_LOG_MAX_SIZE, desc: "Max size of proxy logs"

lib/kamal/configuration.rb

@@ -249,10 +249,16 @@ class Kamal::Configuration
     env_tags.detect { |t| t.name == name.to_s }
   end
 
-  def proxy_publish_args(http_port, https_port, bind_ip = nil)
-    publish_http = [ bind_ip, http_port, PROXY_HTTP_PORT ].compact.join(":")
-    publish_https = [ bind_ip, https_port, PROXY_HTTPS_PORT ].compact.join(":")
-    argumentize "--publish", [ publish_http, publish_https ]
+  def proxy_publish_args(http_port, https_port, bind_ips = nil)
+    ensure_valid_bind_ips(bind_ips)
+
+    (bind_ips || [ nil ]).map do |bind_ip|
+      bind_ip = format_bind_ip(bind_ip)
+      publish_http = [ bind_ip, http_port, PROXY_HTTP_PORT ].compact.join(":")
+      publish_https = [ bind_ip, https_port, PROXY_HTTPS_PORT ].compact.join(":")
+
+      argumentize "--publish", [ publish_http, publish_https ]
+    end.join(" ")
   end
 
   def proxy_logging_args(max_size)
@@ -346,6 +352,15 @@ class Kamal::Configuration
       true
     end
 
+    def ensure_valid_bind_ips(bind_ips)
+      bind_ips.present? && bind_ips.each do |ip|
+        next if ip =~ Resolv::IPv4::Regex || ip =~ Resolv::IPv6::Regex
+        raise Kamal::ConfigurationError, "Invalid publish IP address: #{ip}"
+      end
+
+      true
+    end
+
     def ensure_retain_containers_valid
       raise Kamal::ConfigurationError, "Must retain at least 1 container" if retain_containers < 1
 
@@ -377,6 +392,15 @@ class Kamal::Configuration
       true
     end
 
+    def format_bind_ip(ip)
+      # Ensure IPv6 address inside square brackets - e.g. [::1]
+      if ip =~ Resolv::IPv6::Regex && ip !~ /\[.*\]/
+        "[#{ip}]"
+      else
+        ip
+      end
+    end
+
     def role_names
       raw_config.servers.is_a?(Array) ? [ "web" ] : raw_config.servers.keys.sort
     end