cloudnative wiki

updates-along-the-versions

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updates along the versions

“https://www.youtube.com/playlist?list=PL2We04F3Y_42ay3zqo1XHXWpG1RMdDpBM”

Kubernetes v1.19 (Released: August 2020)

Compared to v1.18:

  • Extended Support: Starting with v1.19, the official support window was extended to one year.
  • EndpointSlice API (Stable): Graduated to GA, providing a scalable and extensible alternative to Endpoints.
  • Ingress API (Stable): The networking.k8s.io/v1 Ingress API graduated to GA. The IngressClass resource was introduced as a replacement for the kubernetes.io/ingress.class annotation.
  • seccomp Support (Alpha): Added a seccompProfile field to Pod securityContext and container securityContext for configuring seccomp profiles.
  • Immutable Secrets and ConfigMaps (Beta): Allowed marking Secrets and ConfigMaps as immutable to prevent accidental updates.
  • Generic Ephemeral Volumes (Alpha): Introduced a way to provision ephemeral volumes using standard storage drivers that support PersistentVolumes.
  • CertificateSigningRequest API (Beta): Improvements made to the CSR API and approval process.
  • Kubelet CRI Support: Introduced support for Container Runtime Interface (CRI) v1.
  • Structured Logging: Continued effort towards structured logging across components.

Kubernetes v1.20 (Released: December 2020)

Compared to v1.19:

  • Volume Snapshot Operations (Stable): Graduated to GA, allowing standard operations for volume snapshots.
  • kubectl debug (Beta): The kubectl debug feature moved to Beta, improving debugging capabilities for pods and nodes.
  • API Priority and Fairness (Beta): Enabled by default, helping prevent API server overloading by classifying and prioritizing requests.
  • PID Limits (Stable): Graduated to GA, allowing limits on process IDs within pods to improve node stability.
  • Graceful Node Shutdown (Alpha): Introduced kubelet awareness of node shutdowns for graceful pod termination.
  • CronJob Controller v2 (Alpha): Introduced an optional, more performant CronJob controller implementation.
  • IPv4/IPv6 Dual-Stack Support (Beta): Re-implemented dual-stack support, enabling Services to operate in dual-stack mode.
  • Dockershim Deprecation: Announced the future removal of the built-in Docker runtime support (Dockershim) in favor of CRI-compliant runtimes.
  • Exec Probe Timeout Handling: Addressed inconsistencies where kubelet did not always respect exec probe timeouts.
  • RuntimeClass (Stable): Graduated to GA.
  • RootCAConfigMap: Introduced RootCAConfigMap for distributing cluster CA bundles to pods.

Kubernetes v1.21 (Released: April 2021)

Compared to v1.20:

  • CronJob (Stable): The CronJob API (batch/v1) graduated to GA.
  • Immutable Secrets and ConfigMaps (Stable): Graduated to GA.
  • Graceful Node Shutdown (Beta): Moved to Beta, allowing configuration via Kubelet config.
  • PersistentVolume Health Monitor (Beta): Introduced monitoring for PV health from CSI drivers.
  • PodDisruptionBudget API (policy/v1) (Stable): Graduated to GA. The policy/v1beta1 version was deprecated. An empty selector ({}) now selects all pods in the namespace.
  • IPv6 Dual-Stack Support (Beta - Enabled by Default): Made significant progress towards stable, enabling by default.
  • PodSecurityPolicy Deprecation: PSP was officially deprecated and scheduled for removal in v1.25. Pod Security Admission was introduced as the intended replacement.
  • Topology Aware Hints (Alpha): Introduced as a successor to the deprecated topologyKeys field for topology-aware routing.
  • Indexed Job (Alpha): Added support for Jobs managing pods associated with completion indexes (e.g., for parallel processing).
  • Suspend Job (Alpha): Added the ability to suspend and resume Jobs.

Kubernetes v1.22 (Released: August 2021)

Compared to v1.21:

  • Major API Removals: Many deprecated beta APIs were removed, requiring migration to their stable v1 counterparts. This included:
    • admissionregistration.k8s.io/v1beta1 (Validating/MutatingWebhookConfiguration)
    • apiextensions.k8s.io/v1beta1 (CustomResourceDefinition)
    • apiregistration.k8s.io/v1beta1 (APIService)
    • authentication.k8s.io/v1beta1 (TokenReview)
    • authorization.k8s.io/v1beta1 (SubjectAccessReview 1 types) 1. github.comgithub.com
    • certificates.k8s.io/v1beta1 (CertificateSigningRequest)
    • coordination.k8s.io/v1beta1 (Lease)
    • extensions/v1beta1 and networking.k8s.io/v1beta1 (Ingress - networking.k8s.io/v1 is stable)
    • RBAC resources (rbac.authorization.k8s.io/v1beta1)
    • Storage resources (storage.k8s.io/v1beta1)
  • Server-Side Apply (Stable): Graduated to GA, providing a declarative way to manage resource configurations.
  • Bound Service Account Tokens (Beta): Improved security for service account tokens by binding them to specific pods.
  • Windows Privileged Containers (Alpha): Introduced HostProcess containers for running privileged operations on Windows nodes.
  • Swap on Linux (Alpha): Added preliminary support for allowing Kubernetes nodes to use swap memory.
  • Default Seccomp Profiles (Alpha): Introduced the ability to apply a default seccomp profile (RuntimeDefault) cluster-wide.
  • Memory QoS with cgroups v2 (Alpha): Enabled memory quality-of-service features using Linux cgroup v2.
  • etcd Updated: Upgraded to etcd v3.5.0.

Kubernetes v1.23 (Released: December 2021)

Compared to v1.22:

  • IPv4/IPv6 Dual-Stack Networking (Stable): Graduated to GA.
  • HorizontalPodAutoscaler v2 API (Stable): The autoscaling/v2 API graduated to GA, replacing v2beta2.
  • Generic Ephemeral Volumes (Stable): Graduated to GA.
  • Skip Volume Ownership Change (Stable): The fsGroupChangePolicy field graduated to GA, allowing faster pod startup by skipping recursive permission changes.
  • Pod Security Admission (Beta - Enabled by Default): The replacement for PSP was enabled by default, providing built-in pod security standards (Privileged, Baseline, Restricted).
  • Ephemeral Containers (Beta - Enabled by Default): kubectl debug functionality using ephemeral containers was enabled by default.
  • CRD Validation Expression Language (Beta): Introduced CEL for defining custom validation rules directly within CRDs.
  • gRPC Probes (Alpha): Added support for gRPC health probes for pods.
  • Structured Logging (Beta): Made significant progress adopting structured logging across components.
  • Job Tracking without Pod Completion (Alpha): Added tracking based on Job controller status rather than just Pod status.
  • OpenAPI v3 Support (Beta): Improved support for publishing Kubernetes APIs via OpenAPI v3.

Kubernetes v1.24 (Released: May 2022)

Compared to v1.23:

  • Dockershim Removed: The most significant change. The built-in Docker Engine support via dockershim was completely removed. Clusters must now use other CRI-compliant runtimes like containerd or CRI-O.
  • New Image Registry: The official container image registry moved from k8s.gcr.io to registry.k8s.io.
  • Service Account Token Secrets: Automatic generation of secret-based service account tokens was disabled by default (LegacyServiceAccountTokenNoAutoGeneration=true). The TokenRequest API should be used instead.
  • Beta APIs Off by Default: New beta APIs are no longer enabled by default in clusters. They must be explicitly enabled. Existing beta APIs remained enabled.
  • Storage Capacity Tracking (Stable): Graduated to GA.
  • Volume Expansion for StatefulSets (Stable): Graduated to GA.
  • Non-Graceful Node Shutdown Handling (Beta): Moved to Beta.
  • Contextual Logging (Alpha): Introduced concept for logging with contextual information.
  • OpenAPI v3 (Stable): Kubernetes API publishing via OpenAPI v3 graduated to GA.
  • Network Policy Status (Alpha): Added a status subresource to NetworkPolicy.

Kubernetes v1.25 (Released: August 2022)

Compared to v1.24:

  • PodSecurityPolicy (PSP) Removed: The deprecated PSP API was completely removed. Users must migrate to Pod Security Admission (PSA) or third-party alternatives.
  • Ephemeral Containers (Stable): Graduated to GA.
  • cgroups v2 Support (Stable): Support for the Linux cgroup v2 API graduated to GA.
  • Core CSI Migration (Stable): The framework for migrating in-tree volume plugins (like AWS EBS, GCE PD, Azure Disk) to out-of-tree CSI drivers graduated to GA. Specific driver migrations continued.
  • Windows HostProcess Containers (Beta): Moved to Beta.
  • SeccompDefault (Beta): Enabling default seccomp profiles cluster-wide moved to Beta.
  • endPort in NetworkPolicy (Stable): Support for specifying port ranges in Network Policies graduated to GA.
  • Local Ephemeral Storage Capacity Isolation (Stable): Graduated to GA.
  • KMS v2 API (Alpha): Introduced a new Key Management Service API (v2alpha1) for encryption at rest.
  • API Removals: Several deprecated beta APIs were removed, including batch/v1beta1 (CronJob) and policy/v1beta1 (PodDisruptionBudget, PodSecurityPolicy).
  • In-tree Plugin Deprecations/Removals: GlusterFS & Portworx plugins deprecated; Flocker, Quobyte, StorageOS removed.

Kubernetes v1.26 (Released: December 2022)

Compared to v1.25:

  • Major API Removals: More deprecated beta APIs removed, including:
    • flowcontrol.apiserver.k8s.io/v1beta1 (API Priority and Fairness)
    • autoscaling/v2beta2 (HorizontalPodAutoscaler)
  • CRI v1alpha2 Removed: Support for the older CRI v1alpha2 runtime API was removed. Runtimes must implement CRI v1 (e.g., containerd >= 1.6.0).
  • CPUManager Policy Options (Beta): New options for the CPU Manager graduated to Beta. CPU Manager itself graduated to Stable.
  • Aggregated Discovery (Alpha): Introduced a way to reduce API server discovery load for clients.
  • Dynamic Resource Allocation (Alpha): Introduced a new API for requesting specialized hardware resources (e.g., FPGAs, GPUs) beyond CPU/memory.
  • Delegating FSGroup to CSI Driver (Stable): Graduated to GA. Allows CSI drivers to handle fsGroup permissions.
  • Pod Scheduling Readiness (Alpha): Introduced schedulingGates to allow external controllers to influence when a pod is considered ready for scheduling.
  • Non-Graceful Node Shutdown Handling (Beta - Enabled by Default): Feature became enabled by default.
  • Cross-Namespace Volume Data Sources (Alpha): Allowed specifying PVC data sources from a different namespace.
  • Retroactive Default StorageClass Assignment (Beta): Allowed assigning a default StorageClass to existing unbound PVCs.
  • CEL for Admission Control (Beta): Using Common Expression Language (CEL) for admission control rules moved to Beta.
  • KMS v2 Improvements (Beta): Enhanced the v2 KMS API.

Kubernetes v1.27 (Released: April 2023)

Compared to v1.26:

  • SeccompDefault (Stable): Graduated to GA, allowing secure-by-default seccomp profiles.
  • Mutable Scheduling Directives for Jobs (Alpha): Allowed updating scheduling directives (like suspend) for Jobs after creation.
  • ReadWriteOncePod PV Access Mode (Beta): A PV access mode restricting volume access to a single pod at a time moved to Beta.
  • Pod Scheduling Readiness (Beta): Moved to Beta.
  • Node Log Query (kubectl node-logs) (Alpha): Added a feature gate and kubectl plugin to query logs directly from nodes via the Kubelet API.
  • Fine-Grained Pod Topology Spread Policies (Beta): Features like minDomains, nodeAffinityPolicy, and nodeTaintsPolicy for Pod Topology Spread constraints moved to Beta.
  • In-Place Pod Vertical Scaling (Alpha): Introduced an alpha feature gate allowing resizing of pod CPU/Memory requests and limits without restarting the pod.
  • Volume Expansion Features (Stable): ExpandCSIVolumes, ExpandInUsePersistentVolumes, ExpandPersistentVolumes feature gates graduated to GA and were locked on.
  • Feature Gate Removals: Several feature gates were removed as their features graduated (e.g., CSIMigration, CSIInlineVolume, EphemeralContainers).
  • Kubelet Evented PLEG (Alpha): Introduced for potential performance improvements in pod lifecycle event generation.

Kubernetes v1.28 (Released: August 2023)

Compared to v1.27:

  • Sidecar Containers (Beta): Introduced native support for sidecar container patterns using restartable init containers.
  • Non-Graceful Node Shutdown Handling (Stable): Graduated to GA.
  • Recovery from Non-Graceful Shutdown (Alpha): Added capability for stateful workloads to recover faster after node shutdown.
  • CRD Validation Rules Language (Stable): Graduated to GA.
  • Admission Control with CEL (Stable): Graduated to GA.
  • KMS v2 Encryption Provider (Stable): The v2 KMS API graduated to GA.
  • Job Mutable Scheduling Directives (Beta): Moved to Beta.
  • API awareness of load balancer behavior (Alpha): Added features for better integration between Services (LoadBalancer type) and cloud provider load balancers.
  • Expanded DNS Configuration (Alpha): Allowed more control over Pod DNS settings.
  • kubectl apply --prune Alpha feature removal.

Kubernetes v1.29 (Released: December 2023)

Compared to v1.28:

  • ReadWriteOncePod PV Access Mode (Stable): Graduated to GA.
  • Node Volume Expansion Secret Support (Stable): CSI drivers can now use secrets during node-side volume expansion; graduated to GA.
  • Init Containers Restart Policy (Beta): Init containers gained a restartPolicy field (default Always), allowing them to restart until completion, useful for sidecar patterns.
  • Ensure Secret Pulled Images (Beta): Kubelet can be configured to always pull images even if present locally when using imagePullSecrets.
  • Queueing Hint Functions for Pod Scheduling (Beta): Allows scheduler plugins to provide hints on when to retry scheduling unschedulable pods.
  • KMS v2 Improvements (Stable): Continued stabilization of KMS v2 features.
  • Reduction of Secret-based Service Account Tokens (Beta): Progressed towards removing auto-generated secret tokens.
  • Structured Authorization Configuration (Alpha): Introduced a structured config file for configuring authorization webhooks.
  • Pod User Namespaces Support (Alpha): Introduced support for running pods within isolated user namespaces for enhanced security.
  • Cluster Trust Bundles (Alpha): Provided a mechanism to distribute X.509 certificate bundles within the cluster.
  • Clean-up of Legacy Package Repositories: Moved away from Google-hosted package repositories (apt.kubernetes.io, yum.kubernetes.io).

Kubernetes v1.30 (Released: April 2024)

Compared to v1.29:

  • Pod User Namespaces (Beta): Moved to Beta.
  • AppArmor Support (Stable): Graduated to GA, allowing enforcement of AppArmor profiles.
  • Node Log Query (Beta): Moved to Beta.
  • Structured Authorization Configuration (Beta): Moved to Beta.
  • Reduction of Secret-based Service Account Tokens (Stable): Graduated to GA; auto-generation is off by default and discouraged.
  • Bound Service Account Token Improvements (Beta): Enhanced security and functionality of projected service account tokens.
  • Prevent Unauthorized Volume Mode Conversion (Beta): Added checks to prevent malicious users from changing volume modes.
  • Volume Attributes Class (Alpha): Introduced a way to define storage classes based on volume attributes.
  • PodReadyToStartContainers Condition (Alpha): Added a Pod condition indicating readiness for container startup.
  • Contextual Logging (Stable): Graduated to GA.
  • kubectl delete -i (interactive mode) (Beta): Moved to Beta.
  • Go Version: Updated to Go 1.22.

Kubernetes v1.31 (Released: August 2024)

Compared to v1.30:

  • Containerd Shims (Stable): Management of containerd shims graduated to GA, simplifying runtime plugin management.
  • MaxUnavailable for StatefulSets (Beta): Introduced maxUnavailable for StatefulSet rolling updates, similar to Deployments.
  • Pod Lifecycle Sleep Action (Alpha): Added an alpha feature to inject sleep delays during container startup/shutdown for debugging or coordination.
  • MatchLabelKeys/MismatchLabelKeys for Pod Topology (Beta): Enhanced Pod Affinity/Anti-Affinity rules for more dynamic matching based on label keys.
  • Admission Control CEL Improvements: Added more functions, metrics, and testing capabilities for CEL-based admission control.
  • Structured Authentication Config (Stable): Graduated to GA.
  • Validating Admission Policy Type Checking (Alpha): Improved static analysis for admission policies.
  • Kubelet Tracing (Alpha): Added experimental tracing support to the kubelet.
  • API Server Self-Signed Cert Rotation (Alpha): Introduced automatic rotation for self-signed certificates used internally by the API server.
  • Go Version: Updated Go toolchain (likely 1.22.x patch).

Kubernetes v1.32 (Released: December 2024)

Compared to v1.31:

  • API Server Tracing (Stable): Graduated to GA.
  • Sidecar Containers (Stable): Native sidecar container support graduated to GA.
  • Recursive Read-only (RRO) Mounts (Beta): Allows mounting volumes and their submounts recursively as read-only.
  • In-Place Pod Vertical Scaling (Beta): Moved to Beta, allowing CPU/Memory resizing without pod restart.
  • Pod User Namespaces (Beta - Host Network Support): Added support for host network pods within user namespaces.
  • Kubelet Resource Metrics Endpoint (Stable): The /metrics/resource endpoint graduated to GA.
  • Prevent Unauthorized Volume Mode Conversion (Stable): Graduated to GA.
  • Validating Admission Policy Improvements: Continued stabilization and feature additions.
  • API Removals: flowcontrol.apiserver.k8s.io/v1beta2 removed (use v1beta3). autoscaling/v2beta2 HorizontalPodAutoscaler removed (use v2).
  • Go Version: Updated to Go 1.23.x.

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