docker-compose - 如何转义环境变量

Question

使用 docker-compose 可以简单地设置 v2 环境变量:

enviroment:
  - MONGO_PATH=mongodb://db-mongo:27017

完整的 docker-compose.yml 文件是:

version: '2'
services:
  web:
    build: .
    environment:
      - MONGO_PATH=mongodb://db-mongo:27017
    ports:
      - "3000:3000"
    volumes:
      - .:/app
      - /app/node_modules
    depends_on: 
      - db-mongo
      - db-redis
  db-mongo:
    image: mongo
    restart: unless-stopped
    command: --smallfiles
    ports:
      - "27017:27017"
    volumes:
      - ./data:/data/db
  [...]

但是，如何转义不是纯字符串的环境变量？

{"database": {"data": {"host": "mongo"}}}

我试过了:

NODE_CONFIG=\{"database": \{"data"\: \{"host": "mongo"\}, "session": \{"host": "redis" \}\}\}
NODE_CONFIG="\{"database": \{"data"\: \{"host": "mongo"\}, "session": \{"host": "redis" \}\}\}"
NODE_CONFIG='{"database": {"data": {"host": "mongo"}, "session": {"host": "redis" }}}'

ERROR: yaml.parser.ParserError: while parsing a block mapping in "./docker-compose.yml", line 6, column 9 expected , but found '}' in "./docker-compose.yml", line 6, column 92

Answer 1

环境变量(包括它们的名称)，必须完全用单引号或双引号括起来:"" 或 ''

environment:
  - 'NODE_CONFIG={"database": {"data": {"host": "mongo"}, "session": {"host": "redis" }}}'

并使用双引号:

environment:
  - 'PORT=3000'
  - "NODE_CONFIG={\"database\": {\"data\": {\"host\": \"mongo\"}, \"session\": {\"host\": \"redis\" }}}"

值得注意的是，使用双引号 "" 就像 bash 一样，将允许将变量放在环境变量中。

"MY_HOME_ENV_VARIABLE=${HOME}"