proxy

package
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 Go to latest Published: Oct 18, 2022 License: Apache-2.0 Imports: 22 Imported by: 154

Documentation

Overview

Package proxy provides proxy and proxy middleware interfaces and implementations.

Index

Constants

View Source 
const Namespace = "github.com/devopsfaith/krakend/proxy"

Namespace to be used in extra config

Variables

View Source 
var (
	// ErrNoBackends is the error returned when an endpoint has no backends defined
	ErrNoBackends = errors.New("all endpoints must have at least one backend")
	// ErrTooManyBackends is the error returned when an endpoint has too many backends defined
	ErrTooManyBackends = errors.New("too many backends for this proxy")
	// ErrTooManyProxies is the error returned when a middleware has too many proxies defined
	ErrTooManyProxies = errors.New("too many proxies for this proxy middleware")
	// ErrNotEnoughProxies is the error returned when an endpoint has not enough proxies defined
	ErrNotEnoughProxies = errors.New("not enough proxies for this endpoint")
)
View Source 
var DefaultHTTPResponseParserConfig = HTTPResponseParserConfig{
	func(_ io.Reader, _ *map[string]interface{}) error { return nil },
	EntityFormatterFunc(func(r Response) Response { return r }),
}

DefaultHTTPResponseParserConfig defines a default HTTPResponseParserConfig

View Source 
var NewRequestBuilderMiddleware = newRequestBuilderMiddleware

NewRequestBuilderMiddleware creates a proxy middleware that parses the request params received from the outter layer and generates the path to the backend endpoints

Functions

func AllowlistPrune 

func AllowlistPrune(wlDict, inDict map[string]interface{}) bool

func CloneRequestHeaders 

func CloneRequestHeaders(headers map[string][]string) map[string][]string

CloneRequestHeaders returns a copy of the received request headers

func CloneRequestParams 

func CloneRequestParams(params map[string]string) map[string]string

CloneRequestParams returns a copy of the received request params

func NewReadCloserWrapper 

func NewReadCloserWrapper(ctx context.Context, in io.ReadCloser) io.Reader

NewReadCloserWrapper Creates a new closeable io.Read

func RegisterResponseCombiner 

func RegisterResponseCombiner(name string, f ResponseCombiner)

RegisterResponseCombiner adds a new response combiner into the internal register

Types

type BackendFactory 

type BackendFactory func(remote *config.Backend) Proxy

BackendFactory creates a proxy based on the received backend configuration

func CustomHTTPProxyFactory 

func CustomHTTPProxyFactory(cf client.HTTPClientFactory) BackendFactory

CustomHTTPProxyFactory returns a BackendFactory. The Proxies it creates will use the received HTTPClientFactory

func HTTPProxyFactory 

func HTTPProxyFactory(client *http.Client) BackendFactory

HTTPProxyFactory returns a BackendFactory. The Proxies it creates will use the received net/http.Client

type EntityFormatter 

type EntityFormatter interface {
	Format(Response) Response
}

EntityFormatter formats the response data

func NewEntityFormatter 

func NewEntityFormatter(remote *config.Backend) EntityFormatter

NewEntityFormatter creates an entity formatter with the received backend definition

type EntityFormatterFunc 

type EntityFormatterFunc func(Response) Response

EntityFormatterFunc holds the formatter function

func (EntityFormatterFunc) Format 

func (e EntityFormatterFunc) Format(entity Response) Response

Format implements the EntityFormatter interface

type Factory 

type Factory interface {
	New(cfg *config.EndpointConfig) (Proxy, error)
}

Factory creates proxies based on the received endpoint configuration.

Both, factories and backend factories, create proxies but factories are designed as a stack makers because they are intended to generate the complete proxy stack for a given frontend endpoint the app would expose and they could wrap several proxies provided by a backend factory

func DefaultFactory 

func DefaultFactory(logger logging.Logger) Factory

DefaultFactory returns a default http proxy factory with the injected logger

func DefaultFactoryWithSubscriber 

func DefaultFactoryWithSubscriber(logger logging.Logger, sF sd.SubscriberFactory) Factory

DefaultFactoryWithSubscriber returns a default proxy factory with the injected logger and subscriber factory

func NewDefaultFactory 

func NewDefaultFactory(backendFactory BackendFactory, logger logging.Logger) Factory

NewDefaultFactory returns a default proxy factory with the injected proxy builder and logger

func NewDefaultFactoryWithSubscriber 

func NewDefaultFactoryWithSubscriber(backendFactory BackendFactory, logger logging.Logger, sF sd.SubscriberFactory) Factory

NewDefaultFactoryWithSubscriber returns a default proxy factory with the injected proxy builder, logger and subscriber factory

func NewShadowFactory 

func NewShadowFactory(f Factory) Factory

NewShadowFactory creates a new shadowFactory using the provided Factory

type FactoryFunc 

type FactoryFunc func(*config.EndpointConfig) (Proxy, error)

FactoryFunc type is an adapter to allow the use of ordinary functions as proxy factories. If f is a function with the appropriate signature, FactoryFunc(f) is a Factory that calls f.

func (FactoryFunc) New 

func (f FactoryFunc) New(cfg *config.EndpointConfig) (Proxy, error)

New implements the Factory interface

type HTTPResponseParser 

type HTTPResponseParser func(context.Context, *http.Response) (*Response, error)

HTTPResponseParser defines how the response is parsed from http.Response to Response object

func DefaultHTTPResponseParserFactory 

func DefaultHTTPResponseParserFactory(cfg HTTPResponseParserConfig) HTTPResponseParser

DefaultHTTPResponseParserFactory is the default implementation of HTTPResponseParserFactory

type HTTPResponseParserConfig 

type HTTPResponseParserConfig struct {
	Decoder         encoding.Decoder
	EntityFormatter EntityFormatter
}

HTTPResponseParserConfig contains the config for a given HttpResponseParser

type HTTPResponseParserFactory 

type HTTPResponseParserFactory func(HTTPResponseParserConfig) HTTPResponseParser

HTTPResponseParserFactory creates HTTPResponseParser from a given HTTPResponseParserConfig

type Metadata 

type Metadata struct {
	Headers    map[string][]string
	StatusCode int
}

Metadata is the Metadata of the Response which contains Headers and StatusCode

type Middleware 

type Middleware func(next ...Proxy) Proxy

Middleware adds a middleware, decorator or wrapper over a collection of proxies, exposing a proxy interface.

Proxy middlewares can be stacked: 

var p Proxy
p := EmptyMiddleware(NoopProxy)
response, err := p(ctx, r)

func NewBackendPluginMiddleware 

func NewBackendPluginMiddleware(logger logging.Logger, remote *config.Backend) Middleware

NewBackendPluginMiddleware returns a backend middleware wrapped (if required) with the plugin middleware. The plugin middleware will try to load all the required plugins from the register and execute them in order. RequestModifiers are executed before passing the request to the next middlware. ResponseModifiers are executed once the response is returned from the next middleware.

func NewConcurrentMiddleware 

func NewConcurrentMiddleware(remote *config.Backend) Middleware

NewConcurrentMiddleware creates a proxy middleware that enables sending several requests concurrently

func NewFlatmapMiddleware 

func NewFlatmapMiddleware(logger logging.Logger, cfg *config.EndpointConfig) Middleware

NewFlatmapMiddleware creates a proxy middleware that enables applying flatmap operations to the proxy response

func NewGraphQLMiddleware 

func NewGraphQLMiddleware(logger logging.Logger, remote *config.Backend) Middleware

NewGraphQLMiddleware returns a middleware with or without the GraphQL proxy wrapping the next element (depending on the configuration). It supports both queries and mutations. For queries, it completes the variables object using the request params. For mutations, it overides the defined variables with the request body. The resulting request will have a proper graphql body with the query and the variables

func NewLoadBalancedMiddleware 

func NewLoadBalancedMiddleware(remote *config.Backend) Middleware

NewLoadBalancedMiddleware creates proxy middleware adding the most perfomant balancer over a default subscriber

func NewLoadBalancedMiddlewareWithSubscriber 

func NewLoadBalancedMiddlewareWithSubscriber(subscriber sd.Subscriber) Middleware

NewLoadBalancedMiddlewareWithSubscriber creates proxy middleware adding the most perfomant balancer over the received subscriber

func NewLoggingMiddleware 

func NewLoggingMiddleware(logger logging.Logger, name string) Middleware

NewLoggingMiddleware creates proxy middleware for logging requests and responses

func NewMergeDataMiddleware 

func NewMergeDataMiddleware(logger logging.Logger, endpointConfig *config.EndpointConfig) Middleware

NewMergeDataMiddleware creates proxy middleware for merging responses from several backends

func NewPluginMiddleware 

func NewPluginMiddleware(logger logging.Logger, endpoint *config.EndpointConfig) Middleware

NewPluginMiddleware returns an endpoint middleware wrapped (if required) with the plugin middleware. The plugin middleware will try to load all the required plugins from the register and execute them in order. RequestModifiers are executed before passing the request to the next middlware. ResponseModifiers are executed once the response is returned from the next middleware.

func NewRandomLoadBalancedMiddleware 

func NewRandomLoadBalancedMiddleware(remote *config.Backend) Middleware

NewRandomLoadBalancedMiddleware creates proxy middleware adding a random balancer over a default subscriber

func NewRandomLoadBalancedMiddlewareWithSubscriber 

func NewRandomLoadBalancedMiddlewareWithSubscriber(subscriber sd.Subscriber) Middleware

NewRandomLoadBalancedMiddlewareWithSubscriber creates proxy middleware adding a random balancer over the received subscriber

func NewRoundRobinLoadBalancedMiddleware 

func NewRoundRobinLoadBalancedMiddleware(remote *config.Backend) Middleware

NewRoundRobinLoadBalancedMiddleware creates proxy middleware adding a round robin balancer over a default subscriber

func NewRoundRobinLoadBalancedMiddlewareWithSubscriber 

func NewRoundRobinLoadBalancedMiddlewareWithSubscriber(subscriber sd.Subscriber) Middleware

NewRoundRobinLoadBalancedMiddlewareWithSubscriber creates proxy middleware adding a round robin balancer over the received subscriber

func NewStaticMiddleware 

func NewStaticMiddleware(logger logging.Logger, endpointConfig *config.EndpointConfig) Middleware

NewStaticMiddleware creates proxy middleware for adding static values to the processed responses

type Proxy 

type Proxy func(ctx context.Context, request *Request) (*Response, error)

Proxy processes a request in a given context and returns a response and an error

func EmptyMiddleware 

func EmptyMiddleware(next ...Proxy) Proxy

EmptyMiddleware is a dummy middleware, useful for testing and fallback

func NewHTTPProxy 

func NewHTTPProxy(remote *config.Backend, cf client.HTTPClientFactory, decode encoding.Decoder) Proxy

NewHTTPProxy creates a http proxy with the injected configuration, HTTPClientFactory and Decoder

func NewHTTPProxyDetailed 

func NewHTTPProxyDetailed(_ *config.Backend, re client.HTTPRequestExecutor, ch client.HTTPStatusHandler, rp HTTPResponseParser) Proxy

NewHTTPProxyDetailed creates a http proxy with the injected configuration, HTTPRequestExecutor, Decoder and HTTPResponseParser

func NewHTTPProxyWithHTTPExecutor 

func NewHTTPProxyWithHTTPExecutor(remote *config.Backend, re client.HTTPRequestExecutor, dec encoding.Decoder) Proxy

NewHTTPProxyWithHTTPExecutor creates a http proxy with the injected configuration, HTTPRequestExecutor and Decoder

func NewShadowProxy 

func NewShadowProxy(p1, p2 Proxy) Proxy

NewShadowProxy returns a Proxy that sends requests to p1 and p2 but ignores the response of p2

func ShadowMiddleware 

func ShadowMiddleware(next ...Proxy) Proxy

ShadowMiddleware is a Middleware that creates a shadowProxy

type Register 

type Register struct {
	// contains filtered or unexported fields
}

func NewRegister 

func NewRegister() *Register

func (Register) GetResponseCombiner 

func (r Register) GetResponseCombiner(name string) (ResponseCombiner, bool)

func (Register) SetResponseCombiner 

func (r Register) SetResponseCombiner(name string, rc ResponseCombiner)

type Request 

type Request struct {
	Method  string
	URL     *url.URL
	Query   url.Values
	Path    string
	Body    io.ReadCloser
	Params  map[string]string
	Headers map[string][]string
}

Request contains the data to send to the backend

func CloneRequest 

func CloneRequest(r *Request) *Request

CloneRequest returns a deep copy of the received request, so the received and the returned proxy.Request do not share a pointer

func (*Request) Clone 

func (r *Request) Clone() Request

Clone clones itself into a new request. The returned cloned request is not thread-safe, so changes on request.Params and request.Headers could generate race-conditions depending on the part of the pipe they are being executed. For thread-safe request headers and/or params manipulation, use the proxy.CloneRequest function.

func (*Request) GeneratePath 

func (r *Request) GeneratePath(URLPattern string)

GeneratePath takes a pattern and updates the path of the request

type RequestWrapper 

type RequestWrapper interface {
	Params() map[string]string
	Headers() map[string][]string
	Body() io.ReadCloser
	Method() string
	URL() *url.URL
	Query() url.Values
	Path() string
}

RequestWrapper is an interface for passing proxy request between the lura pipe and the loaded plugins

type Response 

type Response struct {
	Data       map[string]interface{}
	IsComplete bool
	Metadata   Metadata
	Io         io.Reader
}

Response is the entity returned by the proxy

func NoOpHTTPResponseParser 

func NoOpHTTPResponseParser(ctx context.Context, resp *http.Response) (*Response, error)

NoOpHTTPResponseParser is a HTTPResponseParser implementation that just copies the http response body into the proxy response IO

func NoopProxy 

func NoopProxy(_ context.Context, _ *Request) (*Response, error)

NoopProxy is a do nothing proxy, useful for testing

type ResponseCombiner 

type ResponseCombiner func(int, []*Response) *Response

ResponseCombiner func to merge the collected responses into a single one

type ResponseWrapper 

type ResponseWrapper interface {
	Data() map[string]interface{}
	Io() io.Reader
	IsComplete() bool
	Headers() map[string][]string
	StatusCode() int
}

ResponseWrapper is an interface for passing proxy response between the lura pipe and the loaded plugins

Source Files

View all Source files

Directories

Path Synopsis
Package plugin provides tools for loading and registering proxy plugins
 Package plugin provides tools for loading and registering proxy plugins
tests/error
tests/logger

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