se-grid-configurator

name	se-grid-configurator
description	Configures Selenium Grid 4 (hub-and-node or standalone, including Docker) and wires RemoteWebDriver for parallel and distributed runs. Use when an SDET says "set up Selenium Grid", "run my tests on a remote grid", "dockerize Selenium Grid 4", "point my tests at RemoteWebDriver", or wants parallel execution across nodes. Produces config and code the engineer must run and validate in their environment.
license	MIT
metadata	{"author":"TheTestingAcademy","pack":"selenium","version":"1.0.0"}

Selenium Grid Configurator

You stand up Selenium Grid 4 and connect tests via RemoteWebDriver. All config is a draft the engineer must run in their own environment — you cannot see their network, ports, or host resources.

When to use

• Someone wants distributed/parallel execution across browsers or machines.
• A local test suite must be pointed at a remote grid endpoint.
• Someone asks to "dockerize the grid" or "add nodes for Chrome and Firefox".

Workflow

1. Pick a topology: standalone (single JVM, quickest), hub-and-node (classic distributed), or fully distributed (router/distributor/sessions) for scale.
2. Choose the runtime: local JARs (selenium-server-<v>.jar) or Docker via docker-compose with selenium/hub + selenium/node-chrome/node-firefox.
3. Set grid endpoint & capacity: hub URL (default http://localhost:4444), SE_NODE_MAX_SESSIONS, and --max-sessions for parallelism.
4. Wire RemoteWebDriver in the test with browserName/browserVersion options, pointing at the hub /wd/hub (or root in Grid 4) URL — parameterize the URL by env var.
5. Enable parallelism in TestNG (parallel="methods" + thread-count) so multiple sessions hit the grid at once.
6. Emit compose file + Java, then note ports/versions the engineer must confirm.

Output shape

# docker-compose.yml — Selenium Grid 4 (hub + chrome/firefox nodes)
services:
  selenium-hub:
    image: selenium/hub:4.25.0
    ports: ["4442:4442", "4443:4443", "4444:4444"]
  chrome:
    image: selenium/node-chrome:4.25.0
    depends_on: [selenium-hub]
    environment:
      - SE_EVENT_BUS_HOST=selenium-hub
      - SE_EVENT_BUS_PUBLISH_PORT=4442
      - SE_EVENT_BUS_SUBSCRIBE_PORT=4443
      - SE_NODE_MAX_SESSIONS=4

// RemoteWebDriver pointed at the grid (parameterize the URL by env var)
String gridUrl = System.getProperty("gridUrl", "http://localhost:4444");
ChromeOptions options = new ChromeOptions();
WebDriver driver = new RemoteWebDriver(new URL(gridUrl), options);
// TestNG: <suite parallel="methods" thread-count="4"> to drive concurrent grid sessions

Guardrails

• This config is a draft the engineer must run and validate — ports, image tags, and host capacity are environment-specific.
• Never assume a locator exists in any example test; keep tests locator-agnostic and let the engineer supply real selectors.
• Pin image/JAR versions to the Selenium version in use — don't fabricate a version or use :latest in examples without saying so.
• Size thread-count and SE_NODE_MAX_SESSIONS to real node CPU/RAM; over-subscription causes flakiness, not speed.
• Don't hardcode the hub URL in tests — parameterize by env var/system property for CI portability.
• Always driver.quit() remote sessions so grid slots are released.