[SOLVED] How to pass docker build command arguments to bash files

Issue

I am passing two command line arguments to my docker file like this:

docker build . -t ros-container --build-arg UBUNTU_VERSION=bionic --build-arg ROS_VERSION=melodic 

I'm able to access them in my docker file, tho I couldn't get them in my bash files. I have tried both entrypoint and cmd techniques. But, non of them helped me.

Expectation

I want to access the two arguments,UBUNTU_VERSION & ROS_VERSION, from the 'script_init.bash' file. See the project structure.

Project structure

- ros_tutorials-noetic-devel
   -Dockerfile
   -scripts
       -script_init.bash

Dockerfile

FROM ros:melodic-perception-bionic

# install packages
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update -q && \
apt-get upgrade -yq && \
apt-get install -yq wget curl git build-essential vim sudo lsb-release locales bash- 
completion

# Adjust working directory
RUN locale-gen en_US.UTF-8
RUN useradd -m -d /home/ubuntu ubuntu -p `perl -e 'print crypt("ubuntu", 
"salt"),"\n"'` && \
echo "ubuntu ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers

# declare ros version arg
ARG ROS_VERSION

#declare ubuntu version arg
ARG UBUNTU_VERSION

# setup environment
USER ubuntu
WORKDIR /home/ubuntu
ENV UBUNTU_V=$UBUNTU_VERSION \
ROS_V=$ROS_VERSION
ENV LANG=en_US.UTF-8 LANGUAGE=en_US:en LC_ALL=en_US.UTF-8

CMD COPY ./scripts/script_init.bash /
ENTRYPOINT ["/scripts/script_init.bash /"] 

script_init.bash

#!/bin/bash
set -e

export UBUNTU_CODENAME=$UBUNTU_V
export REPO_DIR=$(dirname "$SCRIPT_DIR")
export CATKIN_DIR="$HOME/catkin_ws"
export ROS_DISTRO=$ROS_V

Solution

I have finally found a solution that works like charm! Once you add the script folder, you can run it with bash command. In this way, you can pass what ever arguments to any bash file within the script folder.

# setup base image
FROM ros:melodic-perception-bionic

# install packages
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update -q && \
    apt-get upgrade -yq && \
    apt-get install -yq wget curl git build-essential vim sudo lsb-release locales bash-completion

# Adjust working directory
RUN locale-gen en_US.UTF-8
RUN useradd -m -d /home/ubuntu ubuntu -p `perl -e 'print crypt("ubuntu", "salt"),"\n"'` && \
    echo "ubuntu ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers

# declare ros version arg
ARG ROS_VERSION

#declare ubuntu version arg
ARG UBUNTU_VERSION

# setup environment
USER ubuntu
WORKDIR /home/ubuntu
ENV UBUNTU_V=$UBUNTU_VERSION \
    ROS_V=$ROS_VERSION
ENV LANG=en_US.UTF-8 LANGUAGE=en_US:en LC_ALL=en_US.UTF-8


# call script files
ADD /scripts /scripts

RUN bash /scripts/script_init.bash

Answered By - Zekarias Taye Hirpo

Answer Checked By - Marilyn (WPSolving Volunteer)