Where execute RUN command from Dockerfile, Host or Intermediate container?

Question

Let say this is an example of a Dockerfile

FROM ubuntu:12.04

MAINTAINER Kimbro Staken version: 0.1

RUN apt-get update && apt-get install -y apache2 && apt-get clean && rm -rf /var/lib/apt/lists/*

ENV APACHE_RUN_USER www-data
ENV APACHE_RUN_GROUP www-data
ENV APACHE_LOG_DIR /var/log/apache2

EXPOSE 80

CMD ["/usr/sbin/apache2", "-D", "FOREGROUND"]

Here is my question: Do I run RUN apt-get update on the host PC or create an intermediate container and run on that and then commit it.

score 2 · Answer 1 · answered May 09 '17 at 06:34

2

It will create intermediate container, run all those commands specified using RUN and then commit it.

answered May 09 '17 at 06:34

Girdhar Sojitra

648
4
14

1

Please provide relevant references. – ashiquzzaman33 May 09 '17 at 06:36
check `docker history myimage` and compare with the output of `docker build -t myimage .` – user2915097 May 09 '17 at 06:45
To understand images and containers , go through at https://docs.docker.com/engine/userguide/storagedriver/imagesandcontainers/ – Girdhar Sojitra May 09 '17 at 07:31
Also go through http://stackoverflow.com/questions/39705085/docker-how-are-intermediate-containers-formed – Girdhar Sojitra May 09 '17 at 07:32

Where execute RUN command from Dockerfile, Host or Intermediate container?

1 Answers1