08 Env Variables

Use this when you want configure-time substitution only.

Source: examples/basic/env-variables/user_config.yml

stage_1:
  image:
    base: "${BASE_IMAGE:-ubuntu:24.04}"
    output: "${PROJECT_NAME:-pei-env-basic}:stage-1"
  ssh:
    enable: true
    port: 22
    host_port: "${SSH_HOST_PORT:-2229}"
    users:
      dev:
        password: "123456"
  apt:
    repo_source: "${APT_REPO_SOURCE:-tuna}"

stage_2:
  image:
    output: "${PROJECT_NAME:-pei-env-basic}:stage-2"
  environment:
    CASE_NAME: "${CASE_NAME:-env-variables}"
    APP_MODE: "${APP_MODE:-dev}"
    RESOLVED_AT: "configure-time"

Try it:

export PROJECT_NAME=my-env-demo
export APP_MODE=prod
pei-docker-cli configure -p demo

After configuration, those values are concrete in generated output. Changing the host env later does nothing until you run configure again.

Read Environment Variables before moving on to the passthrough example.