In a Dockerfile, How to update PATH environment variable?
I have a dockerfile that download and builds GTK from source, but the following line is not updating my image's environment variable:
RUN PATH="/opt/gtk/bin:$PATH"
RUN export PATH
I read that that I should be using ENV to set environment values, but the following instruction doesn't seem to work either:
ENV PATH /opt/gtk/bin:$PATH
This is my entire Dockerfile:
FROM ubuntu
RUN apt-get update
RUN apt-get install -y golang gcc make wget git libxml2-utils libwebkit2gtk-3.0-dev libcairo2 libcairo2-dev libcairo-gobject2 shared-mime-info libgdk-pixbuf2.0-* libglib2-* libatk1.0-* libpango1.0-* xserver-xorg xvfb
# Downloading GTKcd
RUN wget http://ftp.gnome.org/pub/gnome/sources/gtk+/3.12/gtk+-3.12.2.tar.xz
RUN tar xf gtk+-3.12.2.tar.xz
RUN cd gtk+-3.12.2
# Setting environment variables before running configure
RUN CPPFLAGS="-I/opt/gtk/include"
RUN LDFLAGS="-L/opt/gtk/lib"
RUN PKG_CONFIG_PATH="/opt/gtk/lib/pkgconfig"
RUN export CPPFLAGS LDFLAGS PKG_CONFIG_PATH
RUN ./configure --prefix=/opt/gtk
RUN make
RUN make install
# running ldconfig after make install so that the newly installed libraries are found.
RUN ldconfig
# Setting the LD_LIBRARY_PATH environment variable so the systems dynamic linker can find the newly installed libraries.
RUN LD_LIBRARY_PATH="/opt/gtk/lib"
# Updating PATH environment program so that utility binaries installed by the various libraries will be found.
RUN PATH="/opt/gtk/bin:$PATH"
RUN export LD_LIBRARY_PATH PATH
# Collecting garbage
RUN rm -rf gtk+-3.12.2.tar.xz
# creating go code root
RUN mkdir gocode
RUN mkdir gocode/src
RUN mkdir gocode/bin
RUN mkdir gocode/pkg
# Setting the GOROOT and GOPATH enviornment variables, any commands created are automatically added to PATH
RUN GOROOT=/usr/lib/go
RUN GOPATH=/root/gocode
RUN PATH=$GOPATH/bin:$PATH
RUN export GOROOT GOPATH PATH
Answer
You can use Environment Replacement in your Dockerfile as follows:
ENV PATH="/opt/gtk/bin:${PATH}"