Struct HTTPTransport

modules/caddyhttp/reverseproxy/httptransport.go:55–165

HTTPTransport is essentially a configuration wrapper for http.Transport. It defines a JSON structure useful when configuring the HTTP transport for Caddy's reverse proxy. It builds its http.Transport at Provision.

// It defines a JSON structure useful when configuring the HTTP transport
// for Caddy's reverse proxy. It builds its http.Transport at Provision.
type HTTPTransport struct {
	// TODO: It's possible that other transports (like fastcgi) might be
	// able to borrow/use at least some of these config fields; if so,
	// maybe move them into a type called CommonTransport and embed it?

	// Configures the DNS resolver used to resolve the IP address of upstream hostnames.
	Resolver *UpstreamResolver `json:"resolver,omitempty"`

	// Configures TLS to the upstream. Setting this to an empty struct
	// is sufficient to enable TLS with reasonable defaults.
	TLS *TLSConfig `json:"tls,omitempty"`

	// Configures HTTP Keep-Alive (enabled by default). Should only be
	// necessary if rigorous testing has shown that tuning this helps
	// improve performance.
	KeepAlive *KeepAlive `json:"keep_alive,omitempty"`

	// Whether to enable compression to upstream. Default: true
	Compression *bool `json:"compression,omitempty"`

	// Maximum number of connections per host. Default: 0 (no limit)
	MaxConnsPerHost int `json:"max_conns_per_host,omitempty"`

	// If non-empty, which PROXY protocol version to send when
	// connecting to an upstream. Default: off.
	ProxyProtocol string `json:"proxy_protocol,omitempty"`

	// URL to the server that the HTTP transport will use to proxy
	// requests to the upstream. See http.Transport.Proxy for
	// information regarding supported protocols. This value takes
	// precedence over `HTTP_PROXY`, etc.
	//
	// Providing a value to this parameter results in
	// requests flowing through the reverse_proxy in the following
	// way:
	//
	// User Agent ->
	//  reverse_proxy ->
	//  forward_proxy_url -> upstream
	//
	// Default: http.ProxyFromEnvironment
	// DEPRECATED: Use NetworkProxyRaw|`network_proxy` instead. Subject to removal.
	ForwardProxyURL string `json:"forward_proxy_url,omitempty"`

	// How long to wait before timing out trying to connect to
	// an upstream. Default: `3s`.
	DialTimeout caddy.Duration `json:"dial_timeout,omitempty"`

	// How long to wait before spawning an RFC 6555 Fast Fallback
	// connection. A negative value disables this. Default: `300ms`.
	FallbackDelay caddy.Duration `json:"dial_fallback_delay,omitempty"`

	// How long to wait for reading response headers from server. Default: No timeout.
	ResponseHeaderTimeout caddy.Duration `json:"response_header_timeout,omitempty"`

	// The length of time to wait for a server's first response
	// headers after fully writing the request headers if the
	// request has a header "Expect: 100-continue". Default: No timeout.