RunChecks runs each check, displays it's warnings/errors, and once all are processed will exit if any errors occurred.

DirAvailableCheck checks if the given directory either does not exist, or is empty.

ExternalEtcdVersionCheck checks if version of external etcd meets the demand of kubeadm.

ExtraArgsCheck checks if arguments are valid.

FileAvailableCheck checks that the given file does not already exist.

FileContentCheck checks that the given file contains the string Content.

FileExistingCheck checks that the given file does not already exist.

FirewalldCheck checks if firewalld is enabled or active, and if so outputs a warning.

HostnameCheck checks if hostname match dns sub domain regex.

HTTPProxyCheck checks if https connection to specific host is going to be done directly or over proxy.

InPathCheck checks if the given executable is present in the path.

IsRootCheck verifies user is root.

PortOpenCheck ensures the given port is available for use.

ServiceCheck verifies that the given service is enabled and active.

SwapCheck warns if swap is enabled.

Checker validates the state of the system to ensure kubeadm will be successful as often as possilble.