Merge pull request #5214 from jtattermusch/fedora_overlay_fun

Fix fedora21 distribtests for python and ruby
diff --git a/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile b/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile
index b44fcff..1eb4c1e 100644
--- a/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile
@@ -29,4 +29,9 @@
 
 FROM fedora:21
 
+# Make yum work properly under docker when using overlay storage driver.
+# https://bugzilla.redhat.com/show_bug.cgi?id=1213602#c9
+# https://github.com/docker/docker/issues/10180
+RUN yum install -y yum-plugin-ovl
+
 RUN yum clean all && yum update -y && yum install -y python python-pip
diff --git a/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile
index 598dac5..b567c5b 100644
--- a/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile
@@ -29,6 +29,11 @@
 
 FROM fedora:21
 
+# Make yum work properly under docker when using overlay storage driver.
+# https://bugzilla.redhat.com/show_bug.cgi?id=1213602#c9
+# https://github.com/docker/docker/issues/10180
+RUN yum install -y yum-plugin-ovl
+
 RUN yum clean all && yum update -y && yum install -y ruby
 
 RUN gem install bundler