Feature Stages

This page provides a description of the various stages that Agones features can be in, and the relative maturity and support level expected for each level.

Supported Versions

Agones versions are expressed as x.y.z, where x is the major version, y is the minor version, and z is the patch version , following Semantic Versioning terminology.

Agones Features

A feature within Agones can be in Alpha, Beta or Stable stage.

Feature Gates

Alpha and Beta features can be enabled or disabled through the agones.featureGates configuration option that can be found in the Helm configuration documentation.

The current set of alpha and beta feature gates are:

Feature Name Gate Default Stage Since
Multicluster Allocation* N/A Enabled Alpha 0.11.0
Example Gate (not in use) Example Disabled None 0.13.0

*Multicluster Allocation was started before this process was in place, and therefore is enabled by default, and will not have a feature flag.

Description of Stages

Alpha

An Alpha feature means:

  • Disabled by default.
  • Might be buggy. Enabling the feature may expose bugs.
  • Support for this feature may be dropped at any time without notice.
  • The API may change in incompatible ways in a later software release without notice.
  • Recommended for use only in short-lived testing clusters, due to increased risk of bugs and lack of long-term support.

Beta

A Beta feature means:

  • Enabled by default, but able to be disabled through a feature gate.
  • The feature is well tested. Enabling the feature is considered safe.
  • Support for the overall feature will not be dropped, though details may change.
  • The schema and/or semantics of objects may change in incompatible ways in a subsequent beta or stable releases. When this happens, we will provide instructions for migrating to the next version. This may require deleting, editing, and re-creating API objects. The editing process may require some thought. This may require downtime for applications that rely on the feature.
  • Recommended for only non-business-critical uses because of potential for incompatible changes in subsequent releases. If you have multiple clusters that can be upgraded independently, you may be able to relax this restriction.

Stable

A Stable feature means:

  • The feature is enabled and the corresponding feature gate no longer exists.
  • Stable versions of features will appear in released software for many subsequent versions.

Feature Stage Indicators

There are a variety of features with Agones, how can we determine what stage each feature is in?

Below are indicators for each type of functionality that can be used to determine the feature stage for a given aspect of Agones.

Custom Resource Definitions (CRDs)

This refers to Kubernetes resource for Agones, such as GameServer, Fleet and GameServerAllocation.

New CRDs

For new resources, the stage of the resource will be indicated by the apiVersion of the resource.

For example: apiVersion: "agones.dev/v1" is a stable resource, apiVersion: "agones.dev/v1beta1" is a beta stage resource, and apiVersion: "agones.dev/v1alpha1" is an alpha stage resource.

New CRD attributes

When alpha and beta attributes are added to an existing stable Agones CRD, we will follow the Kubernetes Adding Unstable Features to Stable Versions Guide to optimise on the least amount of breaking changes for users as attributes progress through feature stages.

alpha and beta attributes will be added to the existing CRD as optional and documented with their feature stage. Attempting to populate these alpha and beta attributes on an Agones CRD will return a validation error if their accompanying Feature Flag is not enabled.

alpha and beta attributes can be subject to change of name and structure, and will result in breaking changes before moving to a stable stage. These changes will be outlined in release notes and feature documentation.

Agones Game Server SDK

Any alpha or beta Game Server SDK functionality will be a subpackage of the sdk package. For example , functionality found in a sdk.alphav1 package should be considered at the alpha feature stage.

Only experimental functionality will be found in any alpha and beta SDK packages, and as such may change as development occurs.

As SDK features move to through feature stages towards stable, the previous version of the SDK API will remain for at least one release to enable easy migration to the more stable feature stage (i.e. from alpha -> beta, beta -> stable)

Any other SDK functionality not marked as alpha or beta is assumed to be stable.

REST & gRPC APIs

REST and gRPC API will have versioned paths where appropriate to indicate their feature stage.

For example, a REST API with a prefix of v1alpha1 is an alpha stage feature: http://api.example.com/v1alpha1/exampleaction.

Similar to the SDK, any alpha or beta gRPC functionality will be a subpackage of the main API package. For example, functionality found in a api.alphav1 package should be considered at the alpha feature stage.


Last modified March 28, 2020: update local.md (#1437) (6ff2787)