in-container

Check if the current process is running inside a container (Docker, Podman).

• Zero dependencies
• Async, non-blocking detection (no execSync/spawnSync)
• Results cached per-process — safe to call repeatedly
• Ships with TypeScript types out of the box
• Resolves false (never throws) on platforms without container-specific paths, e.g. Windows or macOS hosts

Install

npm install in-container

Usage

import { inContainer, inDocker, inPodman } from 'in-container';

if (await inContainer()) {
    console.log('Running inside a container');
}

import { inDocker } from 'in-container';

if (await inDocker()) {
    console.log('Running inside a Docker container');
}

import { inPodman } from 'in-container';

if (await inPodman()) {
    console.log('Running inside a Podman container');
}

API

inDocker()

Returns Promise<boolean> — whether the current process appears to be running inside a Docker container.

Detected via /.dockerenv, a docker cgroup segment in /proc/self/cgroup, or a /docker/containers/ mount in /proc/self/mountinfo. Resolves false on platforms without those paths (e.g. Windows, macOS hosts).

The result is cached after the first call, since it cannot change for the lifetime of the process.

inPodman()

Returns Promise<boolean> — whether the current process appears to be running inside a Podman container.

Detected via /run/.containerenv or a libpod/podman cgroup segment in /proc/self/cgroup. Resolves false on platforms without those paths (e.g. Windows, macOS hosts).

The result is cached after the first call, since it cannot change for the lifetime of the process.

inContainer()

Returns Promise<boolean> — whether the current process appears to be running inside a Docker or Podman container. Equivalent to (await inDocker()) || (await inPodman()).

Requirements

This package is ESM-only. Import it with import; it cannot be require()-d from CommonJS.

License

MIT