Merge pull request #132 from fly-apps/ffi

Search for ffi in the gemfile

Author: rubys

dockerfile-rails.gemspec

@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |spec|
   spec.name        = "dockerfile-rails"
-  spec.version     = "1.7.1"
+  spec.version     = "1.7.2"
   spec.authors     = [
     "Sam Ruby",
   ]

lib/generators/dockerfile_generator.rb

@@ -741,7 +741,7 @@ def build_packages
     packages = %w(build-essential libyaml-dev)
     packages += @@packages["build"] if @@packages["build"]
     packages += %w(nodejs npm) if (node_version == "lts") && (not using_execjs?)
-    packages << "libffi-dev" if  @@packages["ffi"]
+    packages << "libffi-dev" if @gemfile.include?("ffi")
 
     # add databases: sqlite3, postgres, mysql
     packages << "pkg-config" if options.sqlite3? || @sqlite3