Here is an update -> I have the following modifications (yes its still messy, but you will get the idea) to get me to the point where I get another known error:
Dockerfile:
FROM docker.elastic.co/logstash/logstash:6.4.2
ARG GIT_SHA
ENV GIT_SHA=${GIT_SHA}
USER 0
WORKDIR /usr/share/logstash
ENV PATH=/usr/share/logstash/bin:$PATH
Ensure Logstash has a UTF-8 locale available.
RUN locale-gen en_US.UTF-8
ENV LANG='en_US.UTF-8' LC_ALL='en_US.UTF-8'
ENV LANG=en_US.UTF-8
LANGUAGE=en_US.UTF-8
LC_CTYPE=en_US.UTF-8
LC_ALL=en_US.UTF-8
COPY gssapi-1.3.0.gem gssapi-1.3.0.gem
COPY ffi-1.11.1.gem ffi-1.11.1.gem
RUN cat /etc/resolv.conf &&
yum clean all &&
yum update -y && yum install sudo gcc make -y &&
yum clean all &&
curl https://curl.haxx.se/download/curl-7.61.0.tar.gz -o curl-7.61.0.tar.gz &&
tar xvzf curl-7.61.0.tar.gz && cd curl-7.61.0 &&
export GEM_HOME=/usr/share/logstash/vendor/bundle/jruby/2.3.0 &&
/usr/share/logstash/vendor/jruby/bin/jruby /usr/share/logstash/vendor/jruby/bin/gem install -V /usr/share/logstash/ffi-1.11.1.gem &&
/usr/share/logstash/vendor/jruby/bin/jruby /usr/share/logstash/vendor/jruby/bin/gem install -V /usr/share/logstash/gssapi-1.3.0.gem
RUN cat Gemfile > Gemfile2
RUN printf 'gem "ffi"\ngem "gssapi"' >> Gemfile2
RUN cp Gemfile2 Gemfile
./configure --with-darwinssl && make && \
echo "Running make install! " && make install
RUN echo "logstash ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers
USER logstash
And now when I run the webhdfs plugin I get the same error as this post (that has an interesting solution that I am trying now. If this does not work I have to punt, and would advise logstash staff to include this thread in their docs (in some different format), because this is not working with defined gssapi directions.