same issue here when trying to install cassandra as per https://github.com/Dominion-Digital/ambari-cassandra-service getting: stderr: Traceback (most recent call last): File "/var/lib/ambari-agent/cache/stack-hooks/before-ANY/scripts/hook.py", line 35, in BeforeAnyHook().execute() File "/usr/lib/ambari-agent/lib/resource_management/libraries/script/script.py", line 353, in execute method(env) File "/var/lib/ambari-agent/cache/stack-hooks/before-ANY/scripts/hook.py", line 29, in hook setup_users() File "/var/lib/ambari-agent/cache/stack-hooks/before-ANY/scripts/shared_initialization.py", line 50, in setup_users groups = params.user_to_groups_dict[user], KeyError: u'cassandra' Error: Error: Unable to run the custom hook script ['/usr/bin/python', '/var/lib/ambari-agent/cache/stack-hooks/before-ANY/scripts/hook.py', 'ANY', '/var/lib/ambari-agent/data/command-163.json', '/var/lib/ambari-agent/cache/stack-hooks/before-ANY', '/var/lib/ambari-agent/data/structured-out-163.json', 'INFO', '/var/lib/ambari-agent/tmp', 'PROTOCOL_TLSv1_2', ''] stdout: 2018-09-04 05:05:23,042 - Stack Feature Version Info: Cluster Stack=3.0, Command Stack=None, Command Version=None -> 3.0 2018-09-04 05:05:23,048 - Group['hadoop'] {} 2018-09-04 05:05:23,050 - User['zookeeper'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['hadoop'], 'uid': None} Error: Error: Unable to run the custom hook script ['/usr/bin/python', '/var/lib/ambari-agent/cache/stack-hooks/before-ANY/scripts/hook.py', 'ANY', '/var/lib/ambari-agent/data/command-163.json', '/var/lib/ambari-agent/cache/stack-hooks/before-ANY', '/var/lib/ambari-agent/data/structured-out-163.json', 'INFO', '/var/lib/ambari-agent/tmp', 'PROTOCOL_TLSv1_2', ''] 2018-09-04 05:05:23,074 - The repository with version 3.0.0.0-1634 for this command has been marked as resolved. It will be used to report the version of the component which was installed 2018-09-04 05:05:23,081 - Skipping stack-select on CASSANDRA because it does not exist in the stack-select package structure. Command failed after 1 tries any ideas? ... View more