route

Documentation

Overview

Package route implements the per-query branch selection used by zonegitd's canary feature.

This is intentionally a tiny subset of docs/SELECTORS.md — one rule shape only: "hash(client.subnet, salt) % 100 < pct -> branch". The full grammar is a v3 feature; what's here is what the demo actually needs to land UC5 ("send 20% of traffic to canary, snap it back on one ref move").

Index

• type BucketRouter
  • func NewBucketRouter(defaultBranch, canarySpec, salt string) (*BucketRouter, error)
  • func (b *BucketRouter) Route(q resolve.QueryContext) string
  • func (b *BucketRouter) String() string

Types

type BucketRouter

type BucketRouter struct {
	DefaultBranch string
	CanaryBranch  string
	Pct           int    // 0..100; 0 disables, 100 sends everything to canary
	Salt          string // makes independent rollouts independent
}

BucketRouter splits traffic between two branches by hashing the client /24 (IPv4) or /48 (IPv6) into 100 buckets. Buckets 0..Pct-1 go to CanaryBranch; the rest go to DefaultBranch.

Stable: the same client subnet always lands in the same bucket given the same salt. Operators rotate the salt to "reshuffle" cohorts.

func NewBucketRouter

func NewBucketRouter(defaultBranch, canarySpec, salt string) (*BucketRouter, error)

NewBucketRouter validates inputs and returns a router. canarySpec is "branch:pct" (e.g. "canary:20"). defaultBranch is what non-canary traffic resolves to.

func (*BucketRouter) Route

func (b *BucketRouter) Route(q resolve.QueryContext) string

Route picks the branch for q. Implements the resolve.Router interface.

func (*BucketRouter) String

func (b *BucketRouter) String() string

String returns a one-line summary suitable for the metrics info gauge.