change yum to dnf

Dockerfile

@@ -22,14 +22,14 @@ ENV ENV=dev \
 RUN ln -sf /usr/share/zoneinfo/UTC /etc/localtime \
     && echo "NETWORKING=yes" > /etc/sysconfig/network
 
-RUN rm -fr /var/cache/yum/* && yum clean all && yum -y install --setopt=tsflags=nodocs epel-release && yum -y update && \
-    yum -y install net-tools wget curl tar unzip mlocate logrotate strace telnet man vim rsyslog httpd mod_ssl dos2unix cronie supervisor && \
-    yum clean all
+RUN rm -fr /var/cache/dnf/* && dnf clean all && dnf -y install --setopt=tsflags=nodocs epel-release && dnf -y update && \
+    dnf -y install net-tools wget curl tar unzip mlocate logrotate strace telnet man vim rsyslog httpd mod_ssl dos2unix cronie supervisor && \
+    dnf clean all
 
 #install shibboleth, cleanup httpd
 COPY container_files/shibboleth/shibboleth.repo /etc/yum.repos.d/security:shibboleth.repo
-RUN yum -y install shibboleth-$version-\* \
-      && yum clean all
+RUN dnf -y install shibboleth-$version-\* \
+      && dnf clean all
 
 ADD ./container_files/httpd/*.conf /etc/httpd/conf.d/
 ADD ./container_files/shibboleth/* /etc/shibboleth/