我能够通过将多行环境变量作为构建arg传递给docker build来使它正常工作。

I was able to get this working by passing the multiline environment variable as a build arg to docker build.

Dockerfile

FROM ubuntu:latest
ARG CONFIG
ENV CONFIG $CONFIG

构建命令

CONFIG="port: 4466
databases:
  prod:
    connector: mysql
    active: true
    host: 33.333.333.333
    port: 3306
    user: root
    password: pass"
docker build --build-arg CONFIG="$CONFIG" ubuntu:latest env | grep 'CONFIG'