GKE offers a set of capabilities that helps you and yourorganization (from infrastructure operators and workload developers to securityand network engineers) manage clusters, infrastructure, and workloads, onGoogle Cloud and across public cloud and on-premisesenvironments. These capabilities are all built around the idea of thefleet: a logical grouping of Kubernetes clusters and other resources that canbe managed together. Fleets are managed by the Fleet service, also known as the Hub service.

This page describes our expanding portfolio of multi-clustermanagement capabilities and provides resources to get started managing your fleet.

Introducing fleets

Typically, as organizations embrace cloud-native technologies like containers,container orchestration, and service meshes, they reach a point where running asingle cluster is no longer sufficient. There are a variety of reasons whyorganizations choose to deploy multiple clusters to achieve their technical andbusiness objectives; for example, separating production from non-productionenvironments, or separating services across tiers, locales, or teams. You canread more about the benefits and tradeoffs involved in multi-cluster approachesinmulti-cluster use cases.

Google Cloud uses the concept of afleet to simplifymanaging multiple clusters, regardless of which project they exist in and what workloads run on them. For example, suppose your organization has ten Google Cloud projects with two GKE clusters in each project, using them to run multiple different production applications. Without fleets, if you want to make a production-wide change to clusters, you need to make the change on the individual clusters, in multiple projects. Even observing multiple clusters can require switching context between projects. With fleets, you can logically group and normalize clusters, helping you uplevel management and observability from individual clusters to entire groups of clusters, with a single "fleet host project" to view and manage your fleet.

However, fleets can be more than just simple groups of clusters. You can build on fleets by enabling fleet-based features that let you abstract away cluster boundaries - for example, by defining and managing resources that belong to specific teams across multiple clusters, or by automating applying the same configuration across your fleet.

A fleet can be entirely made up ofGoogle Kubernetes Engine clusters on Google Cloud, or include clusters outside Google Cloud.

• To learn more about how fleets work, and to find a complete list offleet-enabled features, seeHow fleets work.

• To learn about current limitations and requirements for using fleets inmulti-cluster deployments, as well as recommendations for implementingfleets in your organization, seeFleet requirements and bestpractices.

• To help you implement fleets in your own systems, read about hypothetical scenariosthat use fleets inFleet examples.

Creating a fleet

Creating a fleet involves registering the clusters you want to manage together to a fleet in your chosen fleet host project. Some cluster types are automatically registered at cluster creation time, while other cluster types must be manually registered.You can read more about how this works in theFleet creation overview, and follow the linked instructions to start adding clusters to your fleet.

When you add a cluster outside Google Cloud to your fleet, aConnect Agent is installed on the cluster to establish control plane connectivity between the cluster and Google Cloud. The agent can traverse NATs, egressproxies, VPNs, and other interconnects that you have between your environmentsand Google. Your Kubernetes clusters and their API servers do notneed public or externally exposed IP addresses. To learn more about the Connect Agent, see theConnect Agent overview.

Authenticating to clusters

Connecting and authenticating users and service accounts to clusters across multiple environments can bechallenging. With fleets, you can choose from two options for consistent, secure authentication to clusters for all your organization's developers and admins.

• Google Cloud identity: If you want to use Google Cloud as your identity provider, the Connect gateway builds on fleets to provide a consistent way to connect to and run commands against your registered clusters from the command line, and makes it simpler to automate DevOps tasks across multiple clusters, including clusters outside Google Cloud. Users don't need direct IP connectivity to a cluster to connect to it using this option. Find out more in theConnect gateway guide.

• Third-party identity: Fleets also support using your existing third-party identity provider, such as Microsoft ADFS, letting you configure your fleet clusters so that users can log in with their existing third-party ID and password. OIDC and LDAP providers are supported. Find out more inSet up the connect gateway with third party identities andIntroducing GKE Identity Service.

With either approach, users can log in to clusters from the command line or from the Google Cloud console.

Google Cloud console

The Google Cloud console provides a central user interface formanaging all of your fleet clusters no matter where they are running. Afteryou have registered your clusters to your fleet, youcan log in to view, monitor, debug, and manage your workloads.

To learn more and to get started, seeWork with clusters from the Google Cloud console.

Who can use fleet management features?

GKE includes fleet management features. Features such asMulti Cluster IngressandCloud Service Mesh are available atadditional cost.

For details of which features are included in each deploymentenvironment, see the GKEdeployment options page.

Use cases

While managing more than one cluster has its challenges, there are many reasonsto deploy multiple clusters to achieve technical and business objectives. Findout more in ourMulti-cluster use cases guide.

What's next?

• Learn more about fleets inHow fleets work
• Start planning how to organize your clusters into fleets withPlan fleet resources
• Get best practices for adding features to your fleet inPlan fleet features
• Get started creating your fleet following theFleet creation overview