v4.3.0

Added

• /flaky?rate=&code=&ms= fails rate percent of the requests with code (503 by default) and answers 200 to the rest, to test retries, circuit breakers and outlier detection. ms makes a failing answer wait first, like /delay. torchio flaky [rate] [code] [ms] calls it.
• /cpu?workers= loads only the first workers and leaves the others idle, to simulate an uneven load across the cores. /info (stress.burn.workers), torchio_cpu_burn_workers, watch and the control panel show how many are loaded. By default it is all of them, as before.
• /connections?count=&hold= opens TCP connections to the server itself and holds them, with the budget MAX_CONNECTIONS (500 by default, 429 when it does not fit), to test connection limits, load balancers and a shutdown with open sockets. /info (connections), /metrics (torchio_connections_held and torchio_connections_limit), watch, the control panel and torchio connections [count] [hold] have it. Like the other endpoints that change the state, TOKEN protects it.
• SHUTDOWN_GRACE_SECONDS makes SIGTERM and SIGINT drain before the process ends: the port closes, the requests and connections already open are served, and it ends when none is left or the time is up. A line each second says what is open, /info (shutdown) and /metrics (torchio_draining, torchio_open_requests, torchio_open_connections) report it, and another signal ends it at once. The default 0 ends the process right away, as before, and now says which signal arrived.

Documentation

• The documentation is a site, at https://torchio.altr.dev, with a page for each part of what used to be the README: the endpoints and their reference (written from the catalog that /help is built from), the command line, watch and the control panel, the configuration, Docker and Kubernetes. It is published with each release.
• The README is short: the install, the first test and the links to the site. It has a section for each way to install (Docker, Homebrew, the install script, the release binary and the source), and it now fits in Docker Hub whole.