Example Dockerfile for non-root application

The following example is a Dockerfile that runs an application as a non-root user with non-group membership.

Dockerfile

FROM ubuntu:latest
 
#Update and install the make utility
RUN apt update && apt install -y make
 
#Copy the source from a folder called “code” and build the application with the make utility
COPY . /code
RUN make /code
 
#Create a new user (user1) and new group (group1); then switch into that user’s context
RUN useradd user1 && groupadd group1
USER user1:group1
 
#Set the default entrypoint for the container
CMD /code/app

Reference:

• https://media.defense.gov/2021/Aug/03/2002820425/-1/-1/1/CTR_KUBERNETES%20HARDENING%20GUIDANCE.PDF