docker-组合无效类型，它应该是字符串。

Question

我在docker-compose.yml文件中配置了以下环境变量：

version: '3'
services:
  server:
    ports:
     - 13045:3000
    environment:
     - NODE_CONFIG: '{"DATABASE_URL":"http://db:5984"}'

在尝试运行docker-compose up时，我会得到以下错误：

services.server.environment contains {"NODE_CONFIG": "{\"DATABASE_URL\":\"http://db:5984\"}"}, which is an invalid type, it should be a string

我需要将环境变量设置为JSON字符串(参见https://github.com/lorenwest/node-config/wiki/Environment-Variables#node_配置)

我在这里做错什么了吗？我能让这件事起作用吗？

Answer 1

环境变量定义为码头编写文件引用状态数组元素的VARIABLE=value。对于您的情况，需要将docker-compose.yml文件更改为：

version: '3'
services:
  server:
    ports:
     - 13045:3000
    environment:
     - NODE_CONFIG='{"DATABASE_URL":"http://db:5984"}'

Answer 2

您需要移除变量前面的破折号。使用这样的语法：

   environment:
     NODE_CONFIG: '{"DATABASE_URL":"http://db:5984"}'

Answer 3

version: '3'
services:
  server:
    ports:
     - 13045:3000
    environment:
     NODE_CONFIG: '{"DATABASE_URL":"http://db:5984"}'

在NODE_CONFIG出去之前先冲过去。由于一些奇怪的原因，这个破折号看起来不被环境所接受。

下面的示例来自官方postgres码头枢纽https://hub.docker.com/_/postgres

# Use postgres/example user/password credentials
version: '3.1'

services:

  db:
    image: postgres
    restart: always
    environment:
      POSTGRES_PASSWORD: example

  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:8080


**QQ edit:** 

Basically, dashes are lists and no dashes are mappings, so that is why environment variable must not have dashes
References:
https://stackoverflow.com/questions/64275361/docker-compose-yml-dash-syntax-in-yaml
https://docs.ansible.com/ansible/latest/reference_appendices/YAMLSyntax.html