Fixes #29213 - Support el8

Author: wbclark

.sync.yml

@@ -2,6 +2,7 @@
 .travis.yml:
   beaker_sets:
     - centos7-64
+    - centos8-64
     - debian10-64
     - ubuntu1804-64
   env:

.travis.yml

@@ -34,6 +34,28 @@ matrix:
         - echo '{"ipv6":true,"fixed-cidr-v6":"2001:db8:1::/64"}' | sudo tee /etc/docker/daemon.json
         - sudo service docker restart
 
+    - rvm: 2.5.1
+      env:
+        - BEAKER_PUPPET_COLLECTION=puppet5
+        - BEAKER_setfile=centos8-64{hostname=centos8-64.example.com}
+      script: bundle exec rake beaker
+      services: docker
+      bundler_args: --without development
+      before_install:
+        - echo '{"ipv6":true,"fixed-cidr-v6":"2001:db8:1::/64"}' | sudo tee /etc/docker/daemon.json
+        - sudo service docker restart
+
+    - rvm: 2.5.1
+      env:
+        - BEAKER_PUPPET_COLLECTION=puppet6
+        - BEAKER_setfile=centos8-64{hostname=centos8-64.example.com}
+      script: bundle exec rake beaker
+      services: docker
+      bundler_args: --without development
+      before_install:
+        - echo '{"ipv6":true,"fixed-cidr-v6":"2001:db8:1::/64"}' | sudo tee /etc/docker/daemon.json
+        - sudo service docker restart
+
     - rvm: 2.5.1
       env:
         - BEAKER_PUPPET_COLLECTION=puppet5

metadata.json

@@ -61,13 +61,15 @@
     {
       "operatingsystem": "RedHat",
       "operatingsystemrelease": [
-        "7"
+        "7",
+        "8"
       ]
     },
     {
       "operatingsystem": "CentOS",
       "operatingsystemrelease": [
-        "7"
+        "7",
+        "8"
       ]
     },
     {