How to Fix: In a Dockerfile, How to update PATH environment variable?

Method 1: Using ENV Instruction

1. Step 1: Add the following line to your Dockerfile before running any commands that require the PATH variable:

ENV PATH /opt/gtk/bin:$PATH

This will set the PATH environment variable for all subsequent commands in your Dockerfile.

Example:

FROM ubuntu
ENV PATH /opt/gtk/bin:$PATH
RUN apt-get update
RUN apt-get install -y golang gcc make wget git libxml2-utils libwebkit2gtk-3.0-dev libcairo2 libcairo2-dev libcairo-gobject

Alternative Method 1: Using a RUN command with the --env option

1. Step 1: Add the following line to your Dockerfile before running any commands that require the PATH variable:

RUN --env=PATH=/opt/gtk/bin:$PATH apt-get update

This will set the PATH environment variable for the current command only.

Method 2: Using a bash shell and setting the PATH variable in the .bashrc file

1. Step 1: Add the following line to your Dockerfile before running any commands that require the PATH variable:

RUN apt-get update
RUN echo 'export PATH=$PATH:/opt/gtk/bin' >> /etc/profile.d/bashrc.sh

This will set the PATH environment variable for all subsequent commands in your Dockerfile.