Crate junction_api

The core implementation for Junction - an xDS dynamically-configurable API load-balancer library.

• Getting Started

This crate allows you to build configuration for a dynamic HTTP client and export it to a control plane or pass it directly to an in-process client. Junction configuration is expressible as plain Rust structs, and can be serialized/deserialized with a serde compatible library.

Core Concepts

Service

The Junction API is built around the idea that you’re always routing requests to a Service, which is an abstract representation of a place you might want traffic to go. A Service can be anything, but to use one in Junction you need a way to uniquely specify it. That could be anything from a DNS name someone else has already set up to a Kubernetes Service in a cluster you’ve connected to Junction.

Routes

An HTTP Route is the client facing half of Junction, and contains most of the things you’d traditionally find in a hand-rolled HTTP client - timeouts, retries, URL rewriting and more. Routes match outgoing requests based on their method, URL, and headers. The http module’s documentation goes into detail on how and why to configure a Route.

Backends

A Backend is a single port on a Service. Backends configuration gives you control over the things you’d normally configure in a reverse proxy or a traditional load balancer. See the backend module’s documentation for more detail.

Crate Feature Flags

The following feature flags are available:

• The kube feature includes conversions from Junction configuration to and from Kubernetes objects. This feature depends on the kube and k8s-openapi crates. See the kube module docs for more detail.

• The xds feature includes conversions from Junction configuration to and from xDS types. This feature depends on the [xds-api][xds_api] crate.

Modules

backend

Backends are the logical target of network traffic. They have an identity and a load-balancing policy. See Backend to get started.

http

HTTP Route configuration. Routes dynamically congfigure things you might put directly in client code like timeouts and retries, failure detection, or picking a different backend based on request data.

kube

Types and re-exports for converting Junction types to Kubernetes objects.

Structs

DnsService

A DNS name to target with traffic.

Duration

A wrapper around std::time::Duration that serializes to and from a f64 number of seconds.

Error

An error converting a Junction API type into another type.

Fraction

A fraction, expressed as a numerator and a denominator.

Hostname

AN RFC 1123 DNS domain name.

KubeService

A Kubernetes Service to target with traffic.

Name

An RFC 1035 compatible name. This name must be useable as a component of a DNS subdomain - it must start with a lowercase ascii alphabetic character and may only consist of ascii lowercase alphanumeric characters and the - character.

Regex

A regular expression.

Enums

Service

A uniquely identifiable service that traffic can be routed to.