---
title: "dot dockerenv"
description: "Today I learned that docker creates an empty file to indicate that you are running in a docker container. Other runtimes like podman commonly use ...."
date: 2026-03-18
published: true
tags:
  - containers
  - docker
  - kubernetes
template: til
---


Today I learned that docker creates an empty `/.dockerenv` file to indicate that
you are running in a docker container.  Other runtimes like podman commonly use
`/run/.containerenv`.  kubernetes uses neither of these, the most common way to
detect if you are running in kubernetes is to check for the presence of the
`KUBERNETES_SERVICE_HOST` environment variable.  There will also be a directory
at `/var/run/secrets/kubernetes.io/serviceaccount` that contains the service
account credentials if you are running in kubernetes.