Protect accessory cli from missing accessory

lib/mrsk/cli/accessory.rb

@@ -6,17 +6,17 @@ class Mrsk::Cli::Accessory < Mrsk::Cli::Base
     if name == "all"
       MRSK.accessory_names.each { |accessory_name| boot(accessory_name) }
     else
+      with_accessory(name) do |accessory|
         directories(name)
         upload(name)
-
-      accessory = MRSK.accessory(name)
         on(accessory.host) { execute *accessory.run }
       end
     end
+  end
 
   desc "upload [NAME]", "Upload accessory files to host"
   def upload(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) do
         accessory.files.each do |(local, remote)|
           accessory.ensure_local_file_present(local)
@@ -27,70 +27,79 @@ class Mrsk::Cli::Accessory < Mrsk::Cli::Base
         end
       end
     end
+  end
 
   desc "directories [NAME]", "Create accessory directories on host"
   def directories(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) do
         accessory.directories.keys.each do |host_path|
           execute *accessory.make_directory(host_path)
         end
       end
     end
+  end
 
   desc "reboot [NAME]", "Reboot accessory on host (stop container, remove container, start new container)"
   def reboot(name)
+    with_accessory(name) do |accessory|
       stop(name)
       remove_container(name)
       boot(name)
     end
+  end
 
   desc "start [NAME]", "Start existing accessory on host"
   def start(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) { execute *accessory.start }
     end
+  end
 
   desc "stop [NAME]", "Stop accessory on host"
   def stop(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) { execute *accessory.stop, raise_on_non_zero_exit: false }
     end
+  end
 
   desc "restart [NAME]", "Restart accessory on host"
   def restart(name)
+    with_accessory(name) do
       stop(name)
       start(name)
     end
+  end
 
   desc "details [NAME]", "Display details about accessory on host (use NAME=all to boot all accessories)"
   def details(name)
     if name == "all"
       MRSK.accessory_names.each { |accessory_name| details(accessory_name) }
     else
-      accessory = MRSK.accessory(name)
+      with_accessory(name) do |accessory|
         on(accessory.host) { puts capture_with_info(*accessory.info) }
       end
     end
+  end
 
   desc "exec [NAME] [CMD]", "Execute a custom command on accessory host"
   option :run, type: :boolean, default: false, desc: "Start a new container to run the command rather than reusing existing"
   def exec(name, cmd)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
-
       runner = options[:run] ? :run_exec : :exec
       on(accessory.host) { |host| puts_by_host host, capture_with_info(*accessory.send(runner, cmd)) }
     end
+  end
 
   desc "bash [NAME]", "Start a bash session on primary host (or specific host set by --hosts)"
   def bash(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
-
       run_locally do
         info "Launching bash session on #{accessory.host}"
         exec accessory.bash(host: accessory.host)
       end
     end
+  end
 
   desc "logs [NAME]", "Show log lines from accessory on host"
   option :since, aliases: "-s", desc: "Show logs since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)"
@@ -98,8 +107,7 @@ class Mrsk::Cli::Accessory < Mrsk::Cli::Base
   option :grep, aliases: "-g", desc: "Show lines with grep match only (use this to fetch specific requests by id)"
   option :follow, aliases: "-f", desc: "Follow logs on primary server (or specific host set by --hosts)"
   def logs(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
-
       grep = options[:grep]
 
       if options[:follow]
@@ -117,34 +125,57 @@ class Mrsk::Cli::Accessory < Mrsk::Cli::Base
         end
       end
     end
+  end
 
   desc "remove [NAME]", "Remove accessory container and image from host (use NAME=all to boot all accessories)"
   def remove(name)
     if name == "all"
       MRSK.accessory_names.each { |accessory_name| remove(accessory_name) }
     else
+      with_accessory(name) do
         stop(name)
         remove_container(name)
         remove_image(name)
         remove_service_directory(name)
       end
     end
+  end
 
   desc "remove_container [NAME]", "Remove accessory container from host"
   def remove_container(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) { execute *accessory.remove_container }
     end
+  end
 
   desc "remove_container [NAME]", "Remove accessory image from host"
   def remove_image(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) { execute *accessory.remove_image }
     end
+  end
 
   desc "remove_service_directory [NAME]", "Remove accessory directory used for uploaded files and data directories from host"
   def remove_service_directory(name)
-    accessory = MRSK.accessory(name)
+    with_accessory(name) do |accessory|
       on(accessory.host) { execute *accessory.remove_service_directory }
     end
+  end
+
+  private
+    def with_accessory(name)
+      if accessory = MRSK.accessory(name)
+        yield accessory
+      else
+        error_on_missing_accessory(name)
+      end
+    end
+
+    def error_on_missing_accessory(name)
+      options = MRSK.accessory_names.presence
+
+      error \
+        "No accessory by the name of '#{name}'" +
+        (options ? " (options: #{options.to_sentence})" : "")
+    end
 end

lib/mrsk/commander.rb

@@ -49,7 +49,7 @@ class Mrsk::Commander
   end
 
   def accessory_names
-    config.accessories.collect(&:name)
+    config.accessories&.collect(&:name) || []
   end
 
 
@@ -74,7 +74,7 @@ class Mrsk::Commander
   end
 
   def accessory(name)
-    (@accessories ||= {})[name] ||= Mrsk::Commands::Accessory.new(config, name: name)
+    config.accessories.detect { |a| a.name == name }
   end