Add centos 8

kitchen/config.yml

@@ -33,6 +33,20 @@ platforms:
     lifecycle:
       post_create:
         - remote: sudo yum -y update
+  - name: centos-8
+    driver_config:
+      image: registry.ocf.co.uk/salt/docker/centos-8-kitchen:base
+      privileged: True
+      run_command: /usr/lib/systemd/systemd
+      use_cache: False
+      remove_images: True
+    provisioner:
+      salt_yum_repo: 'https://repo.saltstack.com/yum/redhat/$releasever/$basearch/%s'
+      salt_yum_rpm_key: 'https://repo.saltstack.com/yum/redhat/7/x86_64/latest/SALTSTACK-GPG-KEY.pub'
+      salt_install: yum
+    lifecycle:
+      post_create:
+        - remote: sudo yum -y update
   - name: ubuntu-16.04
     driver_config:
       image: registry.ocf.co.uk/salt/docker/ubuntu-16.04-kitchen:base