问题
How can I install Docker inside an alpine container and run docker images? I could install, but could not start docker and while running get "docker command not found error".
回答1:
Dockerfile for running docker inside alpine
FROM alpine:3.10
RUN apk add --update docker openrc
RUN rc-update add docker boot
Build docker image
docker build -t docker-alpine .
Run container
docker run -it -v "/var/run/docker.sock:/var/run/docker.sock:rw" docker-alpine:latest /bin/sh
回答2:
All you need is to install Docker CLI in an image based on Alpine and run the container mounting docker.sock. It allows running sibling Docker containers using host's Docker Engine. It is known as Docker-out-of-Docker and is considered a good alternative to running a separate Docker Engine inside a container (aka Docker-in-Docker).
Dockerfile
FROM alpine:3.11
RUN apk update && apk add --no-cache docker-cli
Build the image:
docker build -t alpine-docker .
Run the container mounting the docker.sock (-v /var/run/docker.sock:/var/run/docker.sock):
docker run --rm -it -v /var/run/docker.sock:/var/run/docker.sock alpine-docker docker ps
The command above should successfully run docker ps inside the Alpine-based container.
来源：https://stackoverflow.com/questions/54099218/how-can-i-install-docker-inside-an-alpine-container