How to copy files from docker image to host machine?
30/04/2023
@ Saigon
Linux
Step 1: Prepare dockerfile
In this post, I would like to take an example building html file for jekyll blog.
from ruby:3.2.0 as build
WORKDIR /opt/nguyenvinhlinh.github.io
COPY . /opt/nguyenvinhlinh.github.io
RUN bundle config set --local deployment true
RUN bundle install
RUN bundle exec jekyll build --destination=/opt/nguyenvinhlinh.github.io/dist
FROM scratch as release
COPY --from=build /opt/nguyenvinhlinh.github.io/dist /The build step will make statis file in /opt/nguyenvinhlinh.github.io/dist, then at release stage, it copies all files from that dist directory to /
Step 2: Execute docker build command
$ mkdir -p /var/tmp/nguyenvinhlinh.github.io-dist
$ docker build -f Dockerfile --target=release --output type=local,dest=/var/tmp/nguyenvinhlinh.github.io-dist .
[+] Building 29.7s (12/12) FINISHED
=> [internal] load .dockerignore 0.0s
=> => transferring context: 120B 0.0s
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 424B 0.0s
=> [internal] load metadata for docker.io/library/ruby:3.2.0 1.8s
=> [1/5] FROM docker.io/library/ruby:3.2.0@sha256:98e340a1e5a9a61ee0c30e464a058da093ab8179460ed096a2a763a3abaa6c47 0.0s
=> CACHED [2/5] WORKDIR /opt/nguyenvinhlinh.github.io 0.0s
=> [internal] load build context 0.1s
=> => transferring context: 103.72kB 0.0s
=> [build 3/6] COPY . /opt/nguyenvinhlinh.github.io 0.1s
=> [build 4/6] RUN bundle config set --local deployment true 0.7s
=> [build 5/6] RUN bundle install 23.7s
=> [build 6/6] RUN bundle exec jekyll build --destination=/opt/nguyenvinhlinh.github.io/dist 2.6s
=> [release 1/1] COPY --from=build /opt/nguyenvinhlinh.github.io/dist / 0.2s
=> exporting to client 0.2s
=> => copying files 12.10MBIn this step, the key point here is about to copy all files from stage named release to host directory at /var/tmp/nguyenvinhlinh.github.io-dist.
Good luck, have fun!
References
- Docker, Custom build outputs, https://docs.docker.com/engine/reference/commandline/build/#output