centos 8 and frontend settings to install

centos-8/Dockerfile

@@ -0,0 +1,8 @@
+FROM centos:8
+
+RUN yum -y install epel-release \
+  && yum -y install ansible git \
+  && yum clean headers \
+  && yum clean packages
+
+CMD ["ansible-playbook", "--help"]

ubuntu-20.04/Dockerfile

@@ -1,7 +1,7 @@
 FROM ubuntu:20.04
 
-RUN DEBIAN_FRONTEND=noninteractive apt-get update \
-    && apt-get install -y --no-install-recommends \
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
       software-properties-common \
       apt-utils \
       ansible \