import fs from "node:fs";

import type { IncomingMessage } from "node:http";

import net from "node:net";

import type { GatewayBindMode } from "../config/types.gateway.js";

import {

__resetContainerEnvironmentCacheForTest,

isContainerEnvironment,

} from "../infra/container-environment.js";

import {

pickMatchingExternalInterfaceAddress,

readNetworkInterfaces,

return false;

}

/**

* Detect whether the current process is running inside a container

* (Docker, Podman, or Kubernetes).

*

* Uses two reliable heuristics:

* 1. Presence of well-known container sentinel files such as `/.dockerenv`

* (Docker) or `/run/.containerenv` (Podman).

* 2. Presence of container-related cgroup entries in `/proc/1/cgroup`

* (covers Docker, containerd, and Kubernetes pods).

*

* The result is cached after the first call so filesystem access

* happens at most once per process lifetime.

*/

let _containerCacheResult: boolean | undefined;

export function isContainerEnvironment(): boolean {

if (_containerCacheResult !== undefined) {

return _containerCacheResult;

}

_containerCacheResult = detectContainerEnvironment();

return _containerCacheResult;

}

function detectContainerEnvironment(): boolean {

// 1. Check common Docker/Podman container sentinel files.

for (const sentinelPath of ["/.dockerenv", "/run/.containerenv", "/var/run/.containerenv"]) {

try {

fs.accessSync(sentinelPath, fs.constants.F_OK);

return true;

} catch {

// not present — continue

}

}

// 2. /proc/1/cgroup contains docker, containerd, kubepods, or lxc markers.

// Covers both cgroup v1 (/docker/<id>, /kubepods/...) and cgroup v2

// (kubepods.slice, cri-containerd-<id>.scope) path formats.

try {

const cgroup = fs.readFileSync("/proc/1/cgroup", "utf8");

if (

/\/docker\/|cri-containerd-[0-9a-f]|containerd\/[0-9a-f]{64}|\/kubepods[/.]|\blxc\b/.test(

cgroup,

)

) {

return true;

}

} catch {

// /proc may not exist (macOS, Windows) — not a container

}

return false;

}

/** @internal — test-only helper to reset the cached container detection result. */

export function __resetContainerCacheForTest(): void {

_containerCacheResult = undefined;

}

export {

isContainerEnvironment,

__resetContainerEnvironmentCacheForTest as __resetContainerCacheForTest,

};

/**

* Resolves gateway bind host with fallback strategy.