GetKubeletVersion is helper function that returns version of kubelet available in $PATH.

InitNodeChecks returns checks specific to "kubeadm init".

JoinNodeChecks returns checks specific to "kubeadm join".

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

RunInitNodeChecks executes all individual, applicable to control-plane node checks.

RunJoinNodeChecks executes all individual, applicable to node checks.

RunPullImagesCheck will pull images kubeadm needs if they are not found on the system.

RunRootCheckOnly initializes checks slice of structs and call RunChecks.

RunUpgradeChecks initializes checks slice of structs and call RunChecks.

ContainerRuntimeCheck verifies the container runtime.

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

Error defines struct for communicating error messages generated by preflight checks.

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

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.

HostnameCheck checks if hostname match dns subdomain regex.

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

HTTPProxyCIDRCheck checks if https connection to specific subnet is going to be done directly or over proxy.

ImagePullCheck will pull container images used by kubeadm.

InPathCheck checks if the given executable is present in $PATH.

IsPrivilegedUserCheck verifies user is privileged (linux - root, windows - Administrator).

KubeletVersionCheck validates installed kubelet version.

KubernetesVersionCheck validates Kubernetes and kubeadm versions.

MemCheck checks if the number of megabytes of memory is not less than required.

NumCPUCheck checks if current number of CPUs is not less than required.

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.

SystemVerificationCheck defines struct used for running the system verification node check in test/e2e_node/system.

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