Memcached

A single-node Memcached container. Memcached never speaks first on connect and never logs anything at startup, so neither a listening-port wait nor a log-message wait can tell "up" from "still booting." This module ships a bespoke WaitStrategy (MemcachedRespondsStrategy) that sends a version command over the wire and requires a real VERSION reply before declaring readiness.

Default image: memcached:latestExposed port: 11211

Member	Returns
MemcachedContainer.start(image?)	Promise<MemcachedContainer> — boots the container
.address	The host:port address of the running container

Example

import { MemcachedContainer } from "rightsize/modules";
import * as net from "node:net";

await using cache = await MemcachedContainer.start();
const [host, port] = cache.address.split(":");

// A minimal raw-protocol round-trip (any memcached client works the same way):
const socket = net.connect(Number(port), host);
await new Promise<void>((resolve) => socket.once("connect", resolve));
socket.write("version\r\n");
const reply = await new Promise<string>((resolve) => socket.once("data", (d) => resolve(d.toString())));
console.log(reply.startsWith("VERSION")); // true
socket.end();

Backend notes

• No-arg construction floats to memcached:latest. Verified against memcached:1.6-alpine — latest is Debian-based rather than Alpine, larger to pull but functionally equivalent.
• Compatibility check: the constructor only accepts images whose repository is memcached (registry host, tag, and digest stripped). A different repository throws IncompatibleImageError before any backend call; override with DockerImageName.parse(image).asCompatibleSubstituteFor("memcached") for a verified compatible fork or mirror.
• Otherwise nothing specific to this module — the protocol-level wait strategy exists precisely so this container is trustworthy readiness-wise on either backend, sidestepping the userland-proxy-accepts-early behavior both backends share for a bare port wait (see Wait strategies).