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Docker

A Docker Tutorial for Beginners

Docker cleanup

Dockerfile​

Multistage build for production and development images​

Best practices

Keywords/commands​

  • .dockerignore: file ignore files in the context

  • From : a new build stage and sets the base image.

  • RUN : Execute commands in a new year on top of current image.

  • CMD : the defaults for an executing container.

    • exec, shell, Entrypoint default form.

  • ENTRYPOINT : exec or shell form.

  • LABEL : Add metadata to a image.

  • EXPOSE: container listens on ports and protocols. Default TCP.

  • ENV : environment variable in the following commands.

  • ADD : Add files from the source new files, directories or remote file URLs

  • COPY : takes in a src and destination

  • Add or COPY

  • VOLUME: create a mount point and marks it as externally mounted volume in the host

  • USER: set user access group.

  • WORKDIR: set the working directory for RUN, CMD, ENTRYPOINT, COPY and ADD.

  • ARG: intention - update dockerfile if this arguments changed.

  • ONBUILD: a trigger instruction to be executed at a later time

  • STOPSIGNAL: system call signal that will be sent to the container to exit

  • HEALTHCHECK: detect cases such as a web server that is stuck in an infinite loop and unable to handle new connections

  • SHELL: Change default shell.

Docker commands​

  • BUILD : use Dockerfile and a context(PATH or URL the set of files)