How to force Docker for a clean build of an image

Question

I have build a Docker image from a Docker file using the below command.

$ docker build -t u12_core -f u12_core .

When I am trying to rebuild it

Answer 1

The command docker build --no-cache . solved our similar problem.

Our Dockerfile was:

RUN apt-get update
RUN apt-get -y install php5-fpm

But should have been:

RUN apt-get update && apt-get -y install php5-fpm

To prevent caching the update and install separately.

See: Best practices for writing Dockerfiles