Environment variables

You can set environment variables in your container without altering the container image by using one of the options below.

You should verify Terminal > Integrated: Inherit Env is checked in settings or the variables you set may not appear in the Integrated Terminal. This setting is checked by default.

Option 1: Add individual variables

Depending on what you reference in devcontainer.json:

  • Dockerfile or image: Add the containerEnv property to devcontainer.json to set variables that should apply to the entire container or remoteEnv to set variables for VS Code and related sub-processes (terminals, tasks, debugging, etc.):

    "containerEnv": {
        "MY_CONTAINER_VAR": "some-value-here",
        "MY_CONTAINER_VAR2": "${localEnv:SOME_LOCAL_VAR}"
    },
    "remoteEnv": {
        "PATH": "${containerEnv:PATH}:/some/other/path",
        "MY_REMOTE_VARIABLE": "some-other-value-here",
        "MY_REMOTE_VARIABLE2": "${localEnv:SOME_LOCAL_VAR}"
    }

    As this example illustrates, containerEnv can reference local variables and remoteEnv can reference both local and existing container variables.

Video: Modify PATH in a dev container



  • Docker Compose: Since Docker Compose has built-in support for updating container-wide variables, only remoteEnv is supported in devcontainer.json:

    "remoteEnv": {
        "PATH": "${containerEnv:PATH}:/some/other/path",
        "MY_REMOTE_VARIABLE": "some-other-value-here",
        "MY_REMOTE_VARIABLE2": "${localEnv:SOME_LOCAL_VAR}"
    }

    As this example illustrates, remoteEnv can reference both local and existing container variables.

    To update variables that apply to the entire container, update (or extend) your docker-compose.yml with the following for the appropriate service:

    version: '3'
    services:
      your-service-name-here:
        environment:
          - YOUR_ENV_VAR_NAME=your-value-goes-here
          - ANOTHER_VAR=another-value
         # ...

If you've already built the container and connected to it, run Remote-Containers: Rebuild Container from the Command Palette (F1) to pick up the change. Otherwise run Remote-Containers: Open Folder in Container... to connect to the container.

Option 2: Use an env file

If you have a large number of environment variables that you need to set, you can use a .env file instead. VS Code will automatically pick up a file called .env in your workspace root, but you can also create one in another location.

First, create an environment file somewhere in your source tree. Consider this .devcontainer/devcontainer.env file:

YOUR_ENV_VAR_NAME=your-value-goes-here
ANOTHER_ENV_VAR_NAME=your-value-goes-here

Next, depending on what you reference in devcontainer.json:

  • Dockerfile or image: Edit devcontainer.json and add a path to the devcontainer.env :

    "runArgs": ["--env-file",".devcontainer/devcontainer.env"]
  • Docker Compose: Edit docker-compose.yml and add a path to the devcontainer.env file relative to the Docker Compose file:

    version: '3'
    services:
      your-service-name-here:
        env_file: devcontainer.env
        # ...

If you've already built the container and connected to it, run Remote-Containers: Rebuild Container from the Command Palette (F1) to pick up the change. Otherwise run Remote-Containers: Open Folder in Container... to connect to the container.

Video: Load variables from an .env file