Prevented unnecessary changes to the hosts file

Author: bert-mccutchen

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    ruby-nginx (1.0.0)
+    ruby-nginx (1.0.1)
       erb
       thor
       tty-command (~> 0.10, >= 0.10.1)

lib/ruby/nginx/commands/add_host_mapping.rb

@@ -11,19 +11,35 @@ def initialize(host, ip, sudo: false)
           @ip = ip
           @sudo = sudo
           sudo_reason = "Allow sudo elevation to add \"#{host}\" to /etc/hosts?"
-          cmd = "echo \"#{ip} #{host}\" | #{sudoify("tee -a /etc/hosts", sudo, sudo_reason)}"
 
-          super(cmd:, raise: Ruby::Nginx::ConfigError)
+          super(
+            cmd: "echo \"#{host_config}\" | #{sudoify("tee -a /etc/hosts", sudo, sudo_reason)}",
+            raise: Ruby::Nginx::ConfigError
+          )
         end
 
         def run
-          super
+          super unless added?
         rescue Ruby::Nginx::ConfigError
           raise if @sudo
 
           # Elevate to sudo and try again.
           self.class.new(@host, @ip, sudo: true).run
         end
+
+        private
+
+        def added?
+          hosts.include?(host_config)
+        end
+
+        def hosts
+          @hosts ||= Ruby::Nginx::System::SafeFile.read("/etc/hosts")
+        end
+
+        def host_config
+          "#{@ip} #{@host}"
+        end
       end
     end
   end

lib/ruby/nginx/commands/remove_host_mapping.rb

@@ -7,25 +7,36 @@ module Ruby
   module Nginx
     module Commands
       class RemoveHostMapping < TerminalCommand
-        def initialize(host, sudo: false)
+        def initialize(host, ignore_ip: nil, sudo: false)
           @host = host
+          @ignore_ip = ignore_ip
           @sudo = sudo
           @sudo_reason = "Allow sudo elevation to remove \"#{host}\" from /etc/hosts?"
 
           super(cmd: resolve_command, raise: Ruby::Nginx::ConfigError)
         end
 
         def run
-          super
+          super unless removed?
         rescue Ruby::Nginx::ConfigError
           raise if @sudo
 
           # Elevate to sudo and try again.
-          self.class.new(@host, sudo: true).run
+          self.class.new(@host, ignore_ip: @ignore_ip, sudo: true).run
         end
 
         private
 
+        def removed?
+          hosts.each_line.none? do |host_config|
+            host_config.include?(@host) && (@ignore_ip.nil? || !host_config.include?(@ignore_ip))
+          end
+        end
+
+        def hosts
+          @hosts ||= Ruby::Nginx::System::SafeFile.read("/etc/hosts")
+        end
+
         def darwin_command
           sudoify("sed -i '' '/#{@host}/d' /etc/hosts", @sudo, @sudo_reason)
         end

lib/ruby/nginx/commands/setup_nginx.rb

@@ -20,9 +20,11 @@ class SetupNginx < TerminalCommand
         def initialize(sudo: false)
           @sudo = sudo
           sudo_reason = "Allow sudo elevation to add \"#{INCLUDE_STATEMENT}\" to NGINX configuration file?"
-          cmd = "echo \"#{new_config}\" | #{sudoify("tee #{config_file_path}", sudo, sudo_reason)}"
 
-          super(cmd:, raise: Ruby::Nginx::SetupError)
+          super(
+            cmd: "echo \"#{new_config}\" | #{sudoify("tee #{config_file_path}", sudo, sudo_reason)}",
+            raise: Ruby::Nginx::SetupError
+          )
         end
 
         def run

lib/ruby/nginx/commands/start_nginx.rb

@@ -9,9 +9,8 @@ class StartNginx < TerminalCommand
         def initialize(sudo: false)
           @sudo = sudo
           sudo_reason = "Allow sudo elevation to start NGINX?"
-          cmd = sudoify("nginx", sudo, sudo_reason)
 
-          super(cmd:, raise: Ruby::Nginx::StartError)
+          super(cmd: sudoify("nginx", sudo, sudo_reason), raise: Ruby::Nginx::StartError)
         end
 
         def run

lib/ruby/nginx/commands/stop_nginx.rb

@@ -9,9 +9,8 @@ class StopNginx < TerminalCommand
         def initialize(sudo: false)
           @sudo = sudo
           sudo_reason = "Allow sudo elevation to stop NGINX?"
-          cmd = sudoify("nginx -s stop", sudo, sudo_reason)
 
-          super(cmd:, raise: Ruby::Nginx::StopError)
+          super(cmd: sudoify("nginx -s stop", sudo, sudo_reason), raise: Ruby::Nginx::StopError)
         end
 
         def run

lib/ruby/nginx/commands/validate_nginx_config.rb

@@ -9,9 +9,8 @@ class ValidateNginxConfig < TerminalCommand
         def initialize(sudo: false)
           @sudo = sudo
           sudo_reason = "Allow sudo elevation to validate NGINX config?"
-          cmd = sudoify("nginx -t", sudo, sudo_reason)
 
-          super(cmd:, raise: Ruby::Nginx::ConfigError)
+          super(cmd: sudoify("nginx -t", sudo, sudo_reason), raise: Ruby::Nginx::ConfigError)
         end
 
         def run

lib/ruby/nginx/system/hosts.rb

@@ -9,12 +9,12 @@ module System
       class Hosts
         class << self
           def add(host, ip)
-            remove(host)
-            Commands::AddHostMapping.new(host, ip).run.success?
+            remove(host, ignore_ip: ip)
+            Commands::AddHostMapping.new(host, ip).run&.success?
           end
 
-          def remove(host)
-            Commands::RemoveHostMapping.new(host).run.success?
+          def remove(host, ignore_ip: nil)
+            Commands::RemoveHostMapping.new(host, ignore_ip:).run&.success?
           end
         end
       end

lib/ruby/nginx/version.rb

@@ -2,7 +2,7 @@
 
 module Ruby
   module Nginx
-    VERSION = "1.0.0"
+    VERSION = "1.0.1"
 
     Version = Gem::Version
   end