Example Dockerfile for issue reproduction

.github/ISSUE_TEMPLATE/bug_report.md

@@ -31,6 +31,15 @@ bundle exec puma -C <where_your_config_is> hello.ru
 
 If you cannot reproduce with a hello world application or other simple application, we will have a lot more difficulty helping you fix your issue, because it may be application-specific and not a bug in Puma at all.  
 
+There is also a Dockerfile available for reproducing Linux-specific issues. To use:
+
+```
+$ docker build -f tools/docker/Dockerfile -t puma .
+$ docker run -p 9292:9292 -it puma
+```
+
+This will help you to create a container that reproduces your issue.
+
 **Expected behavior**
 A clear and concise description of what you expected to happen.
 

tools/docker/Dockerfile

@@ -0,0 +1,16 @@
+# Use this Dockerfile to create minimal reproductions of issues
+
+FROM ruby:2.6
+
+# throw errors if Gemfile has been modified since Gemfile.lock
+RUN bundle config --global frozen 1
+
+WORKDIR /usr/src/app
+
+COPY . .
+RUN gem install bundler
+RUN bundle install
+RUN bundle exec rake compile
+
+EXPOSE 9292
+CMD bundle exec bin/puma test/rackup/hello.ru