CentOS 6: ffi requires Ruby version >= 1.9

[incubos]

$ vagrant docker-run centos6 -- fpm-cook package /vagrant/recipes/graylog-server/recipe.rb
==> centos6: Building the container from a Dockerfile...
    centos6: Sending build context to Docker daemon   2.56kB
    centos6: Step 1/7 : FROM centos:centos6
    centos6:  ---> 0cbf37812bff
    centos6: Step 2/7 : MAINTAINER Graylog, Inc. <hello@graylog.com>
    centos6:  ---> Using cache
    centos6:  ---> ee9eb34d04d5
    centos6: Step 3/7 : RUN yum clean all
    centos6:  ---> Using cache
    centos6:  ---> 30d68ed639c7
    centos6: Step 4/7 : RUN yum install -y rubygems ruby-devel make gcc tar rpm-build curl
    centos6:  ---> Using cache
    centos6:  ---> 26d60460ba38
    centos6: Step 5/7 : RUN gem install fpm-cookery --no-ri --no-rdoc
    centos6:  ---> Running in 5e1347261fc1
    centos6: ERROR:  Error installing fpm-cookery:
    centos6:    ffi requires Ruby version >= 1.9.
    centos6: 
    centos6: Building native extensions.  This could take a while...
    centos6: The command '/bin/sh -c gem install fpm-cookery --no-ri --no-rdoc' returned a non-zero code: 1
A Docker command executed by Vagrant didn't complete successfully!
The command run along with the output from the command is shown
below.

Command: ["docker", "build", "--rm=true", "--tag=fpm_cookery/centos:6", "/home/incubos/devel/build/fpm-recipes/docker/centos6", {:notify=>[:stdout, :stderr]}]

Stderr: The command '/bin/sh -c gem install fpm-cookery --no-ri --no-rdoc' returned a non-zero code: 1

[bernd]

Our current builds are based on the centos8 container. Closing this issue.