Documentation ¶
Index ¶
- Constants
- func ActiveDNSAddon(featureGates map[string]bool) string
- func BuildUpgradedDaemonSetsFromConfig(cfg *kubeadmapi.MasterConfiguration, k8sVersion *version.Version) map[string]*apps.DaemonSet
- func CheckClusterHealth(client clientset.Interface, ignoreChecksErrors sets.String) error
- func FetchConfiguration(client clientset.Interface, w io.Writer, cfgPath string) (*kubeadmapiext.MasterConfiguration, error)
- func IsControlPlaneSelfHosted(client clientset.Interface) bool
- func PerformPostUpgradeTasks(client clientset.Interface, cfg *kubeadmapi.MasterConfiguration, ...) error
- func PrepullImagesInParallel(kubePrepuller Prepuller, timeout time.Duration) error
- func SelfHostedControlPlane(client clientset.Interface, waiter apiclient.Waiter, ...) error
- func StaticPodControlPlane(waiter apiclient.Waiter, pathMgr StaticPodPathManager, ...) error
- type ClusterState
- type DaemonSetPrepuller
- type KubeStaticPodPathManager
- func (spm *KubeStaticPodPathManager) BackupEtcdDir() string
- func (spm *KubeStaticPodPathManager) BackupManifestDir() string
- func (spm *KubeStaticPodPathManager) BackupManifestPath(component string) string
- func (spm *KubeStaticPodPathManager) MoveFile(oldPath, newPath string) error
- func (spm *KubeStaticPodPathManager) RealManifestDir() string
- func (spm *KubeStaticPodPathManager) RealManifestPath(component string) string
- func (spm *KubeStaticPodPathManager) TempManifestDir() string
- func (spm *KubeStaticPodPathManager) TempManifestPath(component string) string
- type KubeVersionGetter
- func (g *KubeVersionGetter) ClusterVersion() (string, *versionutil.Version, error)
- func (g *KubeVersionGetter) KubeadmVersion() (string, *versionutil.Version, error)
- func (g *KubeVersionGetter) KubeletVersions() (map[string]uint16, error)
- func (g *KubeVersionGetter) VersionFromCILabel(ciVersionLabel, description string) (string, *versionutil.Version, error)
- type Prepuller
- type StaticPodPathManager
- type Upgrade
- type VersionGetter
- type VersionSkewPolicyErrors
Constants ¶
const ( // MaximumAllowedMinorVersionUpgradeSkew describes how many minor versions kubeadm can upgrade the control plane version in one go MaximumAllowedMinorVersionUpgradeSkew = 1 // MaximumAllowedMinorVersionDowngradeSkew describes how many minor versions kubeadm can upgrade the control plane version in one go MaximumAllowedMinorVersionDowngradeSkew = 1 // MaximumAllowedMinorVersionKubeletSkew describes how many minor versions the control plane version and the kubelet can skew in a kubeadm cluster MaximumAllowedMinorVersionKubeletSkew = 1 )
Variables ¶
This section is empty.
Functions ¶
func ActiveDNSAddon ¶
ActiveDNSAddon returns the version of CoreDNS or kube-dns
func BuildUpgradedDaemonSetsFromConfig ¶
func BuildUpgradedDaemonSetsFromConfig(cfg *kubeadmapi.MasterConfiguration, k8sVersion *version.Version) map[string]*apps.DaemonSet
BuildUpgradedDaemonSetsFromConfig takes a config object and the current version and returns the DaemonSet objects to post to the master
func CheckClusterHealth ¶
CheckClusterHealth makes sure: - the API /healthz endpoint is healthy - all master Nodes are Ready - (if self-hosted) that there are DaemonSets with at least one Pod for all control plane components - (if static pod-hosted) that all required Static Pod manifests exist on disk
func FetchConfiguration ¶
func FetchConfiguration(client clientset.Interface, w io.Writer, cfgPath string) (*kubeadmapiext.MasterConfiguration, error)
FetchConfiguration fetches configuration required for upgrading your cluster from a file (which has precedence) or a ConfigMap in the cluster
func IsControlPlaneSelfHosted ¶
IsControlPlaneSelfHosted returns whether the control plane is self hosted or not
func PerformPostUpgradeTasks ¶
func PerformPostUpgradeTasks(client clientset.Interface, cfg *kubeadmapi.MasterConfiguration, newK8sVer *version.Version, dryRun bool) error
PerformPostUpgradeTasks runs nearly the same functions as 'kubeadm init' would do Note that the markmaster phase is left out, not needed, and no token is created as that doesn't belong to the upgrade
func PrepullImagesInParallel ¶
PrepullImagesInParallel creates DaemonSets synchronously but waits in parallel for the images to pull
func SelfHostedControlPlane ¶
func SelfHostedControlPlane(client clientset.Interface, waiter apiclient.Waiter, cfg *kubeadmapi.MasterConfiguration, k8sVersion *version.Version) error
SelfHostedControlPlane upgrades a self-hosted control plane It works as follows: - The client gets the currently running DaemonSets and their associated Pods used for self-hosting the control plane - A temporary DaemonSet for the component in question is created; but nearly identical to the DaemonSet for the self-hosted component running right now
- Why use this temporary DaemonSet? Because, the RollingUpdate strategy for upgrading DaemonSets first kills the old Pod, and then adds the new one
- This doesn't work for self-hosted upgrades, as if you remove the only API server for instance you have in the cluster, the cluster essentially goes down
- So instead, a nearly identical copy of the pre-upgrade DaemonSet is created and applied to the cluster. In the beginning, this duplicate DS is just idle
- kubeadm waits for the temporary DaemonSet's Pod to become Running - kubeadm updates the real, self-hosted component. This will result in the pre-upgrade component Pod being removed from the cluster
- Luckily, the temporary, backup DaemonSet now kicks in and takes over and acts as the control plane. It recognizes that a new Pod should be created,
- as the "real" DaemonSet is being updated.
- kubeadm waits for the pre-upgrade Pod to become deleted. It now takes advantage of the backup/temporary component - kubeadm waits for the new, upgraded DaemonSet to become Running. - Now that the new, upgraded DaemonSet is Running, we can delete the backup/temporary DaemonSet - Lastly, make sure the API /healthz endpoint still is reachable
TL;DR; This is what the flow looks like in pseudo-code: for [kube-apiserver, kube-controller-manager, kube-scheduler], do:
- Self-Hosted component v1 Running -> Duplicate the DaemonSet manifest
- Self-Hosted component v1 Running (active). Backup component v1 Running (passive) -> Upgrade the Self-Hosted component v1 to v2. -> Self-Hosted component v1 is Deleted from the cluster
- Backup component v1 Running becomes active and completes the upgrade by creating the Self-Hosted component v2 Pod (passive) -> Wait for Self-Hosted component v2 to become Running
- Backup component v1 Running (active). Self-Hosted component v2 Running (passive) -> Backup component v1 is Deleted
- Wait for Self-Hosted component v2 Running to become active
- Repeat for all control plane components
func StaticPodControlPlane ¶
func StaticPodControlPlane(waiter apiclient.Waiter, pathMgr StaticPodPathManager, cfg *kubeadmapi.MasterConfiguration, etcdUpgrade bool) error
StaticPodControlPlane upgrades a static pod-hosted control plane
Types ¶
type ClusterState ¶
type ClusterState struct { // KubeVersion describes the version of the Kubernetes API Server, Controller Manager, Scheduler and Proxy. KubeVersion string // DNSVersion describes the version of the kube-dns images used and manifest version DNSVersion string // KubeadmVersion describes the version of the kubeadm CLI KubeadmVersion string // KubeletVersions is a map with a version number linked to the amount of kubelets running that version in the cluster KubeletVersions map[string]uint16 // EtcdVersion represents the version of etcd used in the cluster EtcdVersion string }
ClusterState describes the state of certain versions for a cluster
type DaemonSetPrepuller ¶
type DaemonSetPrepuller struct {
// contains filtered or unexported fields
}
DaemonSetPrepuller makes sure the control plane images are available on all masters
func NewDaemonSetPrepuller ¶
func NewDaemonSetPrepuller(client clientset.Interface, waiter apiclient.Waiter, cfg *kubeadmapi.MasterConfiguration) *DaemonSetPrepuller
NewDaemonSetPrepuller creates a new instance of the DaemonSetPrepuller struct
func (*DaemonSetPrepuller) CreateFunc ¶
func (d *DaemonSetPrepuller) CreateFunc(component string) error
CreateFunc creates a DaemonSet for making the image available on every relevant node
func (*DaemonSetPrepuller) DeleteFunc ¶
func (d *DaemonSetPrepuller) DeleteFunc(component string) error
DeleteFunc deletes the DaemonSet used for making the image available on every relevant node
func (*DaemonSetPrepuller) WaitFunc ¶
func (d *DaemonSetPrepuller) WaitFunc(component string)
WaitFunc waits for all Pods in the specified DaemonSet to be in the Running state
type KubeStaticPodPathManager ¶
type KubeStaticPodPathManager struct {
// contains filtered or unexported fields
}
KubeStaticPodPathManager is a real implementation of StaticPodPathManager that is used when upgrading a static pod cluster
func (*KubeStaticPodPathManager) BackupEtcdDir ¶
func (spm *KubeStaticPodPathManager) BackupEtcdDir() string
BackupEtcdDir should point to the backup directory used for backuping manifests during the transition
func (*KubeStaticPodPathManager) BackupManifestDir ¶
func (spm *KubeStaticPodPathManager) BackupManifestDir() string
BackupManifestDir should point to the backup directory used for backuping manifests during the transition
func (*KubeStaticPodPathManager) BackupManifestPath ¶
func (spm *KubeStaticPodPathManager) BackupManifestPath(component string) string
BackupManifestPath gets the file path for the component in the backup directory used for backuping manifests during the transition
func (*KubeStaticPodPathManager) MoveFile ¶
func (spm *KubeStaticPodPathManager) MoveFile(oldPath, newPath string) error
MoveFile should move a file from oldPath to newPath
func (*KubeStaticPodPathManager) RealManifestDir ¶
func (spm *KubeStaticPodPathManager) RealManifestDir() string
RealManifestDir should point to the static pod manifest directory used by the kubelet
func (*KubeStaticPodPathManager) RealManifestPath ¶
func (spm *KubeStaticPodPathManager) RealManifestPath(component string) string
RealManifestPath gets the file path for the component in the "real" static pod manifest directory used by the kubelet
func (*KubeStaticPodPathManager) TempManifestDir ¶
func (spm *KubeStaticPodPathManager) TempManifestDir() string
TempManifestDir should point to the temporary directory created for generating new manifests for the upgrade
func (*KubeStaticPodPathManager) TempManifestPath ¶
func (spm *KubeStaticPodPathManager) TempManifestPath(component string) string
TempManifestPath gets the file path for the component in the temporary directory created for generating new manifests for the upgrade
type KubeVersionGetter ¶
type KubeVersionGetter struct {
// contains filtered or unexported fields
}
KubeVersionGetter handles the version-fetching mechanism from external sources
func (*KubeVersionGetter) ClusterVersion ¶
func (g *KubeVersionGetter) ClusterVersion() (string, *versionutil.Version, error)
ClusterVersion gets API server version
func (*KubeVersionGetter) KubeadmVersion ¶
func (g *KubeVersionGetter) KubeadmVersion() (string, *versionutil.Version, error)
KubeadmVersion gets kubeadm version
func (*KubeVersionGetter) KubeletVersions ¶
func (g *KubeVersionGetter) KubeletVersions() (map[string]uint16, error)
KubeletVersions gets the versions of the kubelets in the cluster
func (*KubeVersionGetter) VersionFromCILabel ¶
func (g *KubeVersionGetter) VersionFromCILabel(ciVersionLabel, description string) (string, *versionutil.Version, error)
VersionFromCILabel resolves a version label like "latest" or "stable" to an actual version using the public Kubernetes CI uploads
type Prepuller ¶
Prepuller defines an interface for performing a prepull operation in a create-wait-delete fashion in parallel
type StaticPodPathManager ¶
type StaticPodPathManager interface { // MoveFile should move a file from oldPath to newPath MoveFile(oldPath, newPath string) error // RealManifestPath gets the file path for the component in the "real" static pod manifest directory used by the kubelet RealManifestPath(component string) string // RealManifestDir should point to the static pod manifest directory used by the kubelet RealManifestDir() string // TempManifestPath gets the file path for the component in the temporary directory created for generating new manifests for the upgrade TempManifestPath(component string) string // TempManifestDir should point to the temporary directory created for generating new manifests for the upgrade TempManifestDir() string // BackupManifestPath gets the file path for the component in the backup directory used for backuping manifests during the transition BackupManifestPath(component string) string // BackupManifestDir should point to the backup directory used for backuping manifests during the transition BackupManifestDir() string // BackupEtcdDir should point to the backup directory used for backuping manifests during the transition BackupEtcdDir() string }
StaticPodPathManager is responsible for tracking the directories used in the static pod upgrade transition
func NewKubeStaticPodPathManager ¶
func NewKubeStaticPodPathManager(realDir, tempDir, backupDir, backupEtcdDir string) StaticPodPathManager
NewKubeStaticPodPathManager creates a new instance of KubeStaticPodPathManager
func NewKubeStaticPodPathManagerUsingTempDirs ¶
func NewKubeStaticPodPathManagerUsingTempDirs(realManifestDir string) (StaticPodPathManager, error)
NewKubeStaticPodPathManagerUsingTempDirs creates a new instance of KubeStaticPodPathManager with temporary directories backing it
type Upgrade ¶
type Upgrade struct { Description string Before ClusterState After ClusterState }
Upgrade defines an upgrade possibility to upgrade from a current version to a new one
func GetAvailableUpgrades ¶
func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesAllowed, rcUpgradesAllowed bool, cluster util.EtcdCluster, featureGates map[string]bool) ([]Upgrade, error)
GetAvailableUpgrades fetches all versions from the specified VersionGetter and computes which kinds of upgrades can be performed
func (*Upgrade) CanUpgradeKubelets ¶
CanUpgradeKubelets returns whether an upgrade of any kubelet in the cluster is possible
type VersionGetter ¶
type VersionGetter interface { // ClusterVersion should return the version of the cluster i.e. the API Server version ClusterVersion() (string, *versionutil.Version, error) // KubeadmVersion should return the version of the kubeadm CLI KubeadmVersion() (string, *versionutil.Version, error) // VersionFromCILabel should resolve CI labels like `latest`, `stable`, `stable-1.8`, etc. to real versions VersionFromCILabel(string, string) (string, *versionutil.Version, error) // KubeletVersions should return a map with a version and a number that describes how many kubelets there are for that version KubeletVersions() (map[string]uint16, error) }
VersionGetter defines an interface for fetching different versions. Easy to implement a fake variant of this interface for unit testing
func NewKubeVersionGetter ¶
func NewKubeVersionGetter(client clientset.Interface, writer io.Writer) VersionGetter
NewKubeVersionGetter returns a new instance of KubeVersionGetter
type VersionSkewPolicyErrors ¶
VersionSkewPolicyErrors describes version skew errors that might be seen during the validation process in EnforceVersionPolicies
func EnforceVersionPolicies ¶
func EnforceVersionPolicies(versionGetter VersionGetter, newK8sVersionStr string, newK8sVersion *version.Version, allowExperimentalUpgrades, allowRCUpgrades bool) *VersionSkewPolicyErrors
EnforceVersionPolicies enforces that the proposed new version is compatible with all the different version skew policies