started working on internal supervisor

Author: tebemis

.travis.yml

@@ -1,6 +1,6 @@
 language: ruby
 rvm:
-  - 2.6.3
+  - 2.3.8
 before_install:
   - gem update --system
   - gem install bundler

Gemfile

@@ -1,9 +1,12 @@
 source 'http://rubygems.org'
 
+ruby '2.3.8'
+
 gem "ansi", "~> 1.5"
 gem 'bson', '~> 3.0'
 gem 'git', '~> 1.2'
-gem 'nutella_lib','~>0.4', '>=0.4.24'
+gem "grpc", "~> 1.24"
+gem 'nutella_lib','~>0.5'
 gem 'nokogiri', '~>1.6'
 gem 'slop', '~>4.0'
 gem 'semantic', '~> 1.4'
@@ -17,6 +20,7 @@ group :development do
   gem 'rdoc', '~> 4.0'
   gem 'bundler', '~> 2.0'
   gem 'jeweler', '~> 2.3'
+  gem "grpc-tools", "~> 1.24"
 end
 
 group :test do

Rakefile

@@ -21,6 +21,7 @@ Jeweler::Tasks.new do |gem|
   gem.description = %Q{utella is a framework to create and run RoomApps}
   gem.email = "[email protected]"
   gem.authors = ["Alessandro Gnoli"]
+  gem.required_ruby_version = "~> 2.0"
   # dependencies defined in Gemfile
 end
 Jeweler::RubygemsDotOrgTasks.new

lib/bots/commands_server/commands_server.rb

@@ -1,7 +1,7 @@
 # Command server
 # Connects to MQTT broker and listens for commands over (RPC)
 # Executes the commands and returns the output
-# require 'nutella_lib'
+require 'nutella_lib'
 Dir["#{File.dirname(__FILE__)}/commands/*.rb"].each do |file|
   require_relative "commands/#{File.basename(file, File.extname(file))}"
 end

lib/supervisor/supervisor.proto

@@ -0,0 +1,16 @@
+syntax = "proto3";
+
+service Supervisor {
+  rpc StartProcess (StartProcessRequest) returns (StartProcessResponse);
+}
+
+message StartProcessRequest {
+  string process_name = 1;
+  string process_command = 2;
+  string process_log = 3;
+}
+
+message StartProcessResponse {
+  bool success = 1;
+  string process_pid = 2;
+}

lib/supervisor/supervisor.rb

@@ -0,0 +1,30 @@
+# Super-simple process supervisor
+
+require_relative 'supervisor_services_pb'
+
+class SupervisorServer < Supervisor::Service
+  # say_hello implements the SayHello rpc method.
+  def start_process(start_process_req, _unused_call)
+    puts "Someone requested to start a process!!! #{start_process_req}"
+    res = StartProcessResponse.new(success: true)
+    puts "Responding with: #{res}"
+    res
+  end
+end
+
+# Everything that is not an SIGINT (2), SIGTERM (15), 
+# or a hard SIGKILL (9) (and a SIGSTOP(19) I guess...)
+# will trigger a process restart
+begin
+  # Listen for commands over GRPC
+  # Start and stop processes
+  # Persist after each operation
+  s = GRPC::RpcServer.new
+  s.add_http2_port('0.0.0.0:50051', :this_port_is_insecure)
+  s.handle(SupervisorServer)
+  s.run_till_terminated_or_interrupted([1, 'int', 'SIGQUIT'])
+rescue SignalException => e
+  # Legit termination, exit
+rescue
+  # everything else... restart
+end

lib/supervisor/supervisor_pb.rb

@@ -0,0 +1,6 @@
+require 'grpc'
+require_relative 'supervisor_services_pb'
+
+stub = Supervisor::Stub.new('localhost:50051', :this_channel_is_insecure)
+res = stub.start_process(StartProcessRequest.new({process_name: "p123", process_log: "abc"}))
+puts "Start process? #{res}"

lib/supervisor/supervisor_services_pb.rb

@@ -19,8 +19,12 @@ def initialize
     # Adds a process to supervision
     def add(name, command)
       write_config_file(name, command)
-      @rpc.call("supervisor.reloadConfig")
-      @rpc.call("supervisor.addProcessGroup", name)
+      begin
+        @rpc.call("supervisor.addProcessGroup", name)  
+      rescue => exception
+        # Yup, we're swallowing this one because it returns true if it adds it and
+        # exceptions out if it can't... ^___^
+      end
     end
 
     # Adds a group of process to supervision
@@ -56,6 +60,11 @@ def stop(name)
       @rpc.call("supervisor.stopProcess", name)
     end
 
+    # Gets all the info about a process
+    def getInfo(name)
+      @rpc.call("supervisor.getProcessInfo", name)
+    end
+
 
     private