Dockerfile snippets - How-To Install Docker CLI, etc.

Dockerfile

...
# Docker install 
USER root 
RUN apt-get update && apt-get install -y \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg2 \
    software-properties-common
RUN curl -fsSL https://download.docker.com/linux/$(. /etc/os-release; echo "$ID")/gpg > /tmp/dkey 
RUN apt-key add /tmp/dkey
RUN add-apt-repository \
     "deb [arch=amd64] https://download.docker.com/linux/$(. /etc/os-release; echo "$ID") \
     $(lsb_release -cs) \
     stable"
RUN apt-get update && apt-get install -y docker-ce-cli
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