您缺少 docker 客户端.在 Dockerfile 中像这样安装:

You're missing the docker client. Install it as this in Dockerfile:

RUN curl -fsSLO https://get.docker.com/builds/Linux/x86_64/docker-17.04.0-ce.tgz 
  && tar xzvf docker-17.04.0-ce.tgz 
  && mv docker/docker /usr/local/bin 
  && rm -r docker docker-17.04.0-ce.tgz

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