upstream

Documentation

Overview

Package upstream provides utilities for propagating HTTP headers from incoming API requests to outbound toolset HTTP calls.

Index

• func Handler(next http.Handler) http.Handler
• func HeadersFromContext(ctx context.Context) http.Header
• func NewHeaderTransport(base http.RoundTripper, headers map[string]string) http.RoundTripper
• func NewHeaderTransportWithResolver(base http.RoundTripper, headers map[string]string, resolve HeaderResolver) http.RoundTripper
• func ResolveHeaders(ctx context.Context, headers map[string]string) map[string]string
• func WithHeaders(ctx context.Context, h http.Header) context.Context
• type HeaderResolver

Functions

func Handler

func Handler(next http.Handler) http.Handler

Handler wraps an http.Handler to store the incoming HTTP request headers in the request context for downstream toolset forwarding.

func HeadersFromContext

func HeadersFromContext(ctx context.Context) http.Header

HeadersFromContext retrieves upstream HTTP headers from the context. Returns nil if no headers are present.

func NewHeaderTransport

func NewHeaderTransport(base http.RoundTripper, headers map[string]string) http.RoundTripper

NewHeaderTransport wraps an http.RoundTripper to set custom headers on every outbound request. Header values may contain ${headers.NAME} placeholders that are resolved at request time from upstream headers stored in the request context.

func NewHeaderTransportWithResolver

func NewHeaderTransportWithResolver(base http.RoundTripper, headers map[string]string, resolve HeaderResolver) http.RoundTripper

NewHeaderTransportWithResolver is like NewHeaderTransport but resolves the header values through resolve on every request. A nil resolve falls back to ResolveHeaders (i.e. ${headers.NAME} placeholder resolution only).

func ResolveHeaders

func ResolveHeaders(ctx context.Context, headers map[string]string) map[string]string

ResolveHeaders resolves ${headers.NAME} placeholders in header values using upstream headers from the context. Header names in the placeholder are case-insensitive, matching HTTP header convention.

For example, given the config header:

Authorization: ${headers.Authorization}

and an upstream request with "Authorization: Bearer token", the resolved value will be "Bearer token".

func WithHeaders

func WithHeaders(ctx context.Context, h http.Header) context.Context

WithHeaders returns a new context carrying the given HTTP headers.

Types

type HeaderResolver

type HeaderResolver func(ctx context.Context, headers map[string]string) map[string]string

HeaderResolver resolves configured header values into the final values to set on an outbound request. It is invoked once per request with the request's context, so implementations can consult dynamic sources (e.g. upstream headers stored in the context, or environment providers backed by rotating credentials) without going stale on long-lived connections.