'DEBIAN_FRONTEND=noninteractive' not working inside shell script with apt-get-CodePudding

I'm buildinga a docker image using a Dockerfile to build it. I have put ARG DEBIAN_FRONTEND=noninteractive in the beginning of the Dockerfile to avoid debconf warnings while building.

The warnings does not show up when using apt-get install inside the Dockerfile. However when executing a sh script (install_dependencies.sh) from the Dockerfile that contains apt-get install commands, the warnings show up again. I also tried to set DEBIAN_FRONTEND=noninteractive inside the sh script itself.

I can solve this by adding echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections in the sh script before the apt-get install commands but I would want to avoid that, since any fail in the script would leave debconf select to Noninteractive.

Dockerfile:

FROM ubuntu:18.04

# Avoid warnings by switching to noninteractive
ARG DEBIAN_FRONTEND=noninteractive

WORKDIR /tmp

# Configure APT --> HERE THE WARNINGS 'debconf: unable to initialize frontend: Dialog' ARE NOT DISPLAYED
RUN apt-get update \
    && apt-get -y upgrade \
    && apt-get install -y \
    apt-utils \
    dialog \
    fakeroot \
    software-properties-common \
    2>&1

# Install APT packages --> HERE THE WARNINGS 'debconf: unable to initialize frontend: Dialog' ARE NOT DISPLAYED
RUN apt-get update && apt-get install -y \
    #
    # System packages
    iproute2 \
    procps \
    lsb-release \
    sudo \
    unattended-upgrades \
    dnsutils \
    iputils-ping \
    xauth \
    openssl \
    tar \
    zip \
    #
    # Helpers
    && apt-get install -y \
    ca-certificates \
    curl \
    wget \
    lsof \
    gconf2 \
    gconf-service \
    #
    # Clean up
    && apt-get autoremove -y \
    && apt-get clean -y \
    && rm -rf /var/lib/apt/lists/*

# Install LTE stack dependencies --> HERE THE WARNINGS 'debconf: unable to initialize frontend: Dialog' ARE DISPLAYED
RUN chmod  x install_dependencies.sh \
    && export DEBIAN_FRONTEND=noninteractive; ./install_dependencies.sh

install_dependencies.sh:

#!/bin/sh

export DEBIAN_FRONTEND=noninteractive

APT_PACKAGES="lib32z1 \
    python-setuptools \
    libmysqlclient-dev \
    ninja-build"

install_apt_packages() {
    sudo apt-get install -y tzdata \
        build-essential \
        git

    for package in $APT_PACKAGES;
    do
        sudo apt-get -y install "$package";
    done
}

main() {
    sudo apt-get update && sudo apt-get upgrade -y 
    install_apt_packages
}

main

EDIT: Thanks to @arkadiusz-drabczyk for telling me to remove sudo from the apt-get commands, it makes perfect sense what he says, that the environment variables drop before executing the command.

CodePudding user response：

Drop sudo in your script, there is point to use it if you're running as root. This is also the reason that DEBIAN_FRONTEND has no effect - sudo drops your current user's environment for security reasons, you'd have to use with -E option to make it work.