docker - './docker-compose.yml', service 必须是映射，而不是 NoneType

Question

当我运行:COMPOSE_PROJECT_NAME=zk_test docker-compose up 时，出现错误提示

"ERROR: In file './docker-compose.yml', service must be a mapping, not a NoneType.".

这是我的 yml 文件:

version: '2'
services:
zoo1:
image: zookeeper
restart: always
container_name: zoo1
ports:
- "2181:2181"
environment:
ZOO_MY_ID: 1
ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

zoo2:
image: zookeeper
restart: always
container_name: zoo2
ports:
- "2182:2181"
environment:
ZOO_MY_ID: 2
ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

zoo3:
image: zookeeper
restart: always
container_name: zoo3
ports:
- "2183:2181"
environment:
ZOO_MY_ID: 3
ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

示例图片:

Answer 1

YAML 依赖于缩进。这个

services:
zoo1:

是一个包含两个键的映射，它们都映射到 null(即 Python 中的 None)。

鉴于:

services:
   zoo1:

是嵌套在映射中的映射。键 'services' 具有与键 zoo1 的映射作为值(同样具有值 null)。