Module: VSM::Lens

Defined in:
lib/vsm/lens.rb,
lib/vsm/lens/tui.rb,
lib/vsm/lens/stats.rb,
lib/vsm/lens/server.rb,
lib/vsm/lens/event_hub.rb

Defined Under Namespace

Modules: TUI Classes: EventHub, SSEBody, Server, Stats

Class Method Summary collapse

Class Method Details

.attach!(capsule, host: "127.0.0.1", port: 9292, token: nil) ⇒ Object

Starts a tiny Rack server (Puma or WEBrick) and streams events via SSE. Returns the EventHub so other lenses (e.g., TUI) can also subscribe.



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# File 'lib/vsm/lens.rb', line 12

def self.attach!(capsule, host: "127.0.0.1", port: 9292, token: nil)
  hub = EventHub.new
  capsule.bus.subscribe { |msg| hub.publish(msg) }

  require_relative "lens/stats"
  stats  = Stats.new(hub: hub, capsule: capsule)
  server = Server.new(hub: hub, token: token, stats: stats)


  Thread.new do
    app = server.rack_app

    # Prefer Puma if present:
    if try_run_puma(app, host, port)
      # ok
    elsif try_run_webrick(app, host, port)
      # ok
    else
      warn "        vsm-lens: no Rack handler found. Install one of:\n          - `bundle add puma`\n          - or `bundle add webrick`\n        Then re-run with VSM_LENS=1.\n      MSG\n    end\n  end\n\n  hub\nend\n"

.try_run_puma(app, host, port) ⇒ Object 



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# File 'lib/vsm/lens.rb', line 42

def self.try_run_puma(app, host, port)
  begin
    require "rack/handler/puma"
  rescue LoadError
    return false
  end
  Thread.new do
    Rack::Handler::Puma.run(app, Host: host, Port: port, Silent: true)
  end
  true
rescue => e
  warn "vsm-lens: Puma failed to start: #{e.class}: #{e.message}"
  false
end

.try_run_webrick(app, host, port) ⇒ Object 



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# File 'lib/vsm/lens.rb', line 57

def self.try_run_webrick(app, host, port)
  begin
    require "webrick"                 # provide the server
    require "rack/handler/webrick"    # rack adapter (Rack 3 loads this if webrick gem is present)
  rescue LoadError
    return false
  end
  Thread.new do
    Rack::Handler::WEBrick.run(
      app,
      Host: host, Port: port,
      AccessLog: [],
      Logger: WEBrick::Log.new($stderr, WEBrick::Log::WARN)
    )
  end
  true
rescue => e
  warn "vsm-lens: WEBrick failed to start: #{e.class}: #{e.message}"
  false
end