Class: Pgbus::Web::HealthServer

Inherits:
Object
  • Object
show all
Defined in:
lib/pgbus/web/health_server.rb

Overview

Standalone HTTP health server for the supervisor process. When config.health_port is set, Supervisor#run starts one of these so a Kubernetes kubelet can probe the supervisor directly — the process that forks and watches workers — without the supervisor having to boot Rails, Puma, or the dashboard.

It is intentionally tiny: one accept-loop thread over a TCPServer that reads only the HTTP request line (GET /readyz HTTP/1.1), synthesizes a minimal Rack env, and hands it to Pgbus::Web::HealthApp#call. All routing and the OK/DEGRADED/STALLED → status mapping live in HealthApp, so the mounted-in- Rails path and this standalone path share exactly one implementation.

This is a health probe surface, not a general HTTP server: it speaks just enough HTTP/1.0 to answer a kubelet. It only parses the request line (method + path), ignores headers and body, and closes the connection after each response (no keep-alive).

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(port:, bind: "127.0.0.1", app: nil, logger: nil) ⇒ HealthServer

Returns a new instance of HealthServer.



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# File 'lib/pgbus/web/health_server.rb', line 39

def initialize(port:, bind: "127.0.0.1", app: nil, logger: nil)
  @configured_port = port
  @bind = bind
  @app = app || HealthApp.new
  @logger = logger
  @server = nil
  @thread = nil
  @port = nil
end

Instance Attribute Details

#port ⇒ Integer? (readonly)

Returns the bound port. Equals the configured port, or the OS-assigned port when the configured port was 0 (used in tests). nil before #start.

Returns:

  • (Integer, nil) —

    the bound port. Equals the configured port, or the OS-assigned port when the configured port was 0 (used in tests). nil before #start.



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# File 'lib/pgbus/web/health_server.rb', line 37

def port
  @port
end

Instance Method Details

#start ⇒ Object

Bind the port and start the accept loop. Idempotent: a second call while running is a no-op (so a supervisor restart path can't double-bind).



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# File 'lib/pgbus/web/health_server.rb', line 51

def start
  return if @server

  @server = TCPServer.new(@bind, @configured_port)
  @port = @server.addr[1]
  @thread = Thread.new { accept_loop }
  logger.info { "[Pgbus::Web::HealthServer] listening on #{@bind}:#{@port} (/livez, /readyz)" }
end

#stop ⇒ Object

Close the listening socket (unblocking the accept loop, which then exits) and join the thread. Safe to call when never started or twice.



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# File 'lib/pgbus/web/health_server.rb', line 62

def stop
  server = @server
  @server = nil
  close_socket(server)
  @thread&.join(2)
  @thread = nil
  @port = nil
end