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Published: May 2, 2017 License: Apache-2.0 Imports: 23 Imported by: 0



Package proxy is middleware that proxies HTTP requests.



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func RegisterPolicy

func RegisterPolicy(name string, policy func() Policy)

RegisterPolicy adds a custom policy to the proxy.


type First added in v0.10.0

type First struct{}

First is a policy that selects the fist available host

func (*First) Select added in v0.10.0

func (r *First) Select(pool HostPool, request *http.Request) *UpstreamHost

Select selects the first host from the pool, that is available

type HostPool

type HostPool []*UpstreamHost

HostPool is a collection of UpstreamHosts.

type IPHash added in v0.9.1

type IPHash struct{}

IPHash is a policy that selects hosts based on hashing the request ip

func (*IPHash) Select added in v0.9.1

func (r *IPHash) Select(pool HostPool, request *http.Request) *UpstreamHost

Select selects an up host from the pool using a round robin ordering scheme.

type LeastConn

type LeastConn struct{}

LeastConn is a policy that selects the host with the least connections.

func (*LeastConn) Select

func (r *LeastConn) Select(pool HostPool, request *http.Request) *UpstreamHost

Select selects the up host with the least number of connections in the pool. If more than one host has the same least number of connections, one of the hosts is chosen at random.

type Policy

type Policy interface {
	Select(pool HostPool, r *http.Request) *UpstreamHost

Policy decides how a host will be selected from a pool.

type Proxy

type Proxy struct {
	Next      httpserver.Handler
	Upstreams []Upstream

Proxy represents a middleware instance that can proxy requests.

func (Proxy) ServeHTTP

func (p Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error)

ServeHTTP satisfies the httpserver.Handler interface.

type Random

type Random struct{}

Random is a policy that selects up hosts from a pool at random.

func (*Random) Select

func (r *Random) Select(pool HostPool, request *http.Request) *UpstreamHost

Select selects an up host at random from the specified pool.

type ReverseProxy

type ReverseProxy struct {
	// Director must be a function which modifies
	// the request into a new request to be sent
	// using Transport. Its response is then copied
	// back to the original client unmodified.
	Director func(*http.Request)

	// The transport used to perform proxy requests.
	// If nil, http.DefaultTransport is used.
	Transport http.RoundTripper

	// FlushInterval specifies the flush interval
	// to flush to the client while copying the
	// response body.
	// If zero, no periodic flushing is done.
	FlushInterval time.Duration

ReverseProxy is an HTTP Handler that takes an incoming request and sends it to another server, proxying the response back to the client.

func NewSingleHostReverseProxy

func NewSingleHostReverseProxy(target *url.URL, without string, keepalive int) *ReverseProxy

NewSingleHostReverseProxy returns a new ReverseProxy that rewrites URLs to the scheme, host, and base path provided in target. If the target's path is "/base" and the incoming request was for "/dir", the target request will be for /base/dir. Without logic: target's path is "/", incoming is "/api/messages", without is "/api", then the target request will be for /messages.

func (*ReverseProxy) ServeHTTP

func (rp *ReverseProxy) ServeHTTP(rw http.ResponseWriter, outreq *http.Request, respUpdateFn respUpdateFn) error

ServeHTTP serves the proxied request to the upstream by performing a roundtrip. It is designed to handle websocket connection upgrades as well.

func (*ReverseProxy) UseInsecureTransport added in v0.9.1

func (rp *ReverseProxy) UseInsecureTransport()

UseInsecureTransport is used to facilitate HTTPS proxying when it is OK for upstream to be using a bad certificate, since this transport skips verification.

type RoundRobin

type RoundRobin struct {
	// contains filtered or unexported fields

RoundRobin is a policy that selects hosts based on round robin ordering.

func (*RoundRobin) Select

func (r *RoundRobin) Select(pool HostPool, request *http.Request) *UpstreamHost

Select selects an up host from the pool using a round robin ordering scheme.

type Upstream

type Upstream interface {
	// The path this upstream host should be routed on
	From() string

	// Selects an upstream host to be routed to. It
	// should return a suitable upstream host, or nil
	// if no such hosts are available.
	Select(*http.Request) *UpstreamHost

	// Checks if subpath is not an ignored path
	AllowedPath(string) bool

	// Gets how long to try selecting upstream hosts
	// in the case of cascading failures.
	GetTryDuration() time.Duration

	// Gets how long to wait between selecting upstream
	// hosts in the case of cascading failures.
	GetTryInterval() time.Duration

	// Gets the number of upstream hosts.
	GetHostCount() int

	// Stops the upstream from proxying requests to shutdown goroutines cleanly.
	Stop() error

Upstream manages a pool of proxy upstream hosts.

func NewStaticUpstreams

func NewStaticUpstreams(c caddyfile.Dispenser, host string) ([]Upstream, error)

NewStaticUpstreams parses the configuration input and sets up static upstreams for the proxy middleware. The host string parameter, if not empty, is used for setting the upstream Host header for the health checks if the upstream header config requires it.

type UpstreamHost

type UpstreamHost struct {
	// This field is read & written to concurrently, so all access must use
	// atomic operations.
	Conns             int64 // must be first field to be 64-bit aligned on 32-bit systems
	MaxConns          int64
	Name              string // hostname of this upstream host
	UpstreamHeaders   http.Header
	DownstreamHeaders http.Header
	FailTimeout       time.Duration
	CheckDown         UpstreamHostDownFunc
	WithoutPathPrefix string
	ReverseProxy      *ReverseProxy
	Fails             int32
	// This is an int32 so that we can use atomic operations to do concurrent
	// reads & writes to this value.  The default value of 0 indicates that it
	// is healthy and any non-zero value indicates unhealthy.
	Unhealthy int32

UpstreamHost represents a single proxy upstream

func (*UpstreamHost) Available

func (uh *UpstreamHost) Available() bool

Available checks whether the upstream host is available for proxying to

func (*UpstreamHost) Down

func (uh *UpstreamHost) Down() bool

Down checks whether the upstream host is down or not. Down will try to use uh.CheckDown first, and will fall back to some default criteria if necessary.

func (*UpstreamHost) Full

func (uh *UpstreamHost) Full() bool

Full checks whether the upstream host has reached its maximum connections

type UpstreamHostDownFunc

type UpstreamHostDownFunc func(*UpstreamHost) bool

UpstreamHostDownFunc can be used to customize how Down behaves.

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