docs/serving

Knative Serving

Knative Serving builds on Kubernetes and Istio to support deploying and serving of serverless applications and functions. Serving is easy to get started with and scales to support advanced scenarios.

The Knative Serving project provides middleware primitives that enable:

• Rapid deployment of serverless containers
• Automatic scaling up and down to zero
• Routing and network programming for Istio components
• Point-in-time snapshots of deployed code and configurations

Serving resources

Knative Serving defines a set of objects as Kubernetes Custom Resource Definitions (CRDs). These objects are used to define and control how your serverless workload behaves on the cluster:

• Service: The service.serving.knative.dev resource automatically manages the whole lifecycle of your workload. It controls the creation of other objects to ensure that your app has a route, a configuration, and a new revision for each update of the service. Service can be defined to always route traffic to the latest revision or to a pinned revision.
• Route: The route.serving.knative.dev resource maps a network endpoint to a one or more revisions. You can manage the traffic in several ways, including fractional traffic and named routes.
• Configuration: The configuration.serving.knative.dev resource maintains the desired state for your deployment. It provides a clean separation between code and configuration and follows the Twelve-Factor App methodology. Modifying a configuration creates a new revision.
• Revision: The revision.serving.knative.dev resource is a point-in-time snapshot of the code and configuration for each modification made to the workload. Revisions are immutable objects and can be retained for as long as useful.

Getting Started

To get started with Serving, check out one of the hello world sample projects. These projects use the Service resource, which manages all of the details for you.

With the Service resource, a deployed service will automatically have a matching route and configuration created. Each time the Service is updated, a new revision is created.

For more information on the resources and their interactions, see the Resource Types Overview in the Knative Serving repository.

More samples and demos

• Autoscaling with Knative Serving
• Source-to-URL with Knative Serving
• Telemetry with Knative Serving
• REST API sample

Setting up Logging and Metrics

• Installing Logging, Metrics and Traces
• Accessing Logs
• Accessing Metrics
• Accessing Traces
• Setting up a logging plugin

Debugging Knative Serving issues

• Debugging Application Issues
• Debugging Performance Issues

Configuration and Networking

• Configuring outbound network access
• Configuring cluster local routes
• Using a custom domain
• Assigning a static IP address for Knative on Google Kubernetes Engine

Known Issues

See the Knative Serving Issues page for a full list of known issues.

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Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License.