Breaking rockylinux platform out (#399)

* breaking rockylinux out into it's own platform, Curl is already available in 8 and 9 containers and installing curl on 9 causes a conflict with the already installed curl-minimal package.

* fixing typo.

lib/kitchen/docker/helpers/dockerfile_helper.rb

@@ -34,12 +34,14 @@ def dockerfile_platform
             gentoo_paludis_platform
           when 'opensuse/tumbleweed', 'opensuse/leap', 'opensuse', 'sles'
             opensuse_platform
-          when 'rhel', 'centos', 'oraclelinux', 'amazonlinux', 'rockylinux'
+          when 'rhel', 'centos', 'oraclelinux', 'amazonlinux'
             rhel_platform
           when 'centosstream'
             centosstream_platform
           when 'almalinux'
             almalinux_platform
+          when 'rockylinux'
+            rockylinux_platform
           when 'photon'
             photonos_platform
           else
@@ -140,6 +142,16 @@ def almalinux_platform
           CODE
         end
 
+        def rockylinux_platform
+          <<-CODE
+            ENV container docker
+            RUN yum clean all
+            RUN yum install -y sudo openssh-server openssh-clients which
+            RUN [ -f "/etc/ssh/ssh_host_rsa_key" ] || ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ''
+            RUN [ -f "/etc/ssh/ssh_host_dsa_key" ] || ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key -N ''
+          CODE
+        end
+
         def photonos_platform
           <<-CODE
             ENV container docker