reverseproxy: Wire up some http transport options in Caddyfile (#3843)

caddytest/integration/caddyfile_adapt/reverse_proxy_options.txt

@@ -10,6 +10,14 @@ https://example.com {
 		buffer_requests
 
 		transport http {
+			read_buffer 10MB
+			write_buffer 20MB
+			max_response_header 30MB
+			dial_timeout 3s
+			dial_fallback_delay 5s
+			response_header_timeout 8s
+			expect_continue_timeout 9s
+
 			versions h2c 2
 			compression off
 			max_conns_per_host 5
@@ -68,13 +76,20 @@ https://example.com {
 													},
 													"transport": {
 														"compression": false,
+														"dial_fallback_delay": 5000000000,
+														"dial_timeout": 3000000000,
+														"expect_continue_timeout": 9000000000,
 														"max_conns_per_host": 5,
 														"max_idle_conns_per_host": 2,
+														"max_response_header_size": 30000000,
 														"protocol": "http",
+														"read_buffer_size": 10000000,
+														"response_header_timeout": 8000000000,
 														"versions": [
 															"h2c",
 															"2"
-														]
+														],
+														"write_buffer_size": 20000000
 													},
 													"upstreams": [
 														{

modules/caddyhttp/reverseproxy/caddyfile.go

@@ -586,9 +586,13 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 // UnmarshalCaddyfile deserializes Caddyfile tokens into h.
 //
 //     transport http {
-//         read_buffer  <size>
+//         read_buffer             <size>
-//         write_buffer <size>
+//         write_buffer            <size>
-//         dial_timeout <duration>
+//         max_response_header     <size>
+//         dial_timeout            <duration>
+//         dial_fallback_delay     <duration>
+//         response_header_timeout <duration>
+//         expect_continue_timeout <duration>
 //         tls
 //         tls_client_auth <automate_name> | <cert_file> <key_file>
 //         tls_insecure_skip_verify
@@ -627,6 +631,16 @@ func (h *HTTPTransport) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				}
 				h.WriteBufferSize = int(size)
 
+			case "max_response_header":
+				if !d.NextArg() {
+					return d.ArgErr()
+				}
+				size, err := humanize.ParseBytes(d.Val())
+				if err != nil {
+					return d.Errf("invalid max response header size '%s': %v", d.Val(), err)
+				}
+				h.MaxResponseHeaderSize = int64(size)
+
 			case "dial_timeout":
 				if !d.NextArg() {
 					return d.ArgErr()
@@ -637,6 +651,36 @@ func (h *HTTPTransport) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				}
 				h.DialTimeout = caddy.Duration(dur)
 
+			case "dial_fallback_delay":
+				if !d.NextArg() {
+					return d.ArgErr()
+				}
+				dur, err := caddy.ParseDuration(d.Val())
+				if err != nil {
+					return d.Errf("bad fallback delay value '%s': %v", d.Val(), err)
+				}
+				h.FallbackDelay = caddy.Duration(dur)
+
+			case "response_header_timeout":
+				if !d.NextArg() {
+					return d.ArgErr()
+				}
+				dur, err := caddy.ParseDuration(d.Val())
+				if err != nil {
+					return d.Errf("bad timeout value '%s': %v", d.Val(), err)
+				}
+				h.ResponseHeaderTimeout = caddy.Duration(dur)
+
+			case "expect_continue_timeout":
+				if !d.NextArg() {
+					return d.ArgErr()
+				}
+				dur, err := caddy.ParseDuration(d.Val())
+				if err != nil {
+					return d.Errf("bad timeout value '%s': %v", d.Val(), err)
+				}
+				h.ExpectContinueTimeout = caddy.Duration(dur)
+
 			case "tls_client_auth":
 				if h.TLS == nil {
 					h.TLS = new(TLSConfig)