reverseproxy: Support performing pre-check requests (#4739)

2 files changed, 152 insertions, 19 deletions

diff --git a/caddytest/integration/caddyfile_adapt/forward_auth_authelia.txt b/caddytest/integration/caddyfile_adapt/forward_auth_authelia.txt
new file mode 100644
index 0000000..e7cbb0f
--- /dev/null
+++ b/caddytest/integration/caddyfile_adapt/forward_auth_authelia.txt
@@ -0,0 +1,137 @@
+app.example.com {
+	forward_auth authelia:9091 {
+		uri /api/verify?rd=https://authelia.example.com
+		copy_headers Remote-User Remote-Groups Remote-Name Remote-Email
+	}
+
+	reverse_proxy backend:8080
+}
+----------
+{
+	"apps": {
+		"http": {
+			"servers": {
+				"srv0": {
+					"listen": [
+						":443"
+					],
+					"routes": [
+						{
+							"match": [
+								{
+									"host": [
+										"app.example.com"
+									]
+								}
+							],
+							"handle": [
+								{
+									"handler": "subroute",
+									"routes": [
+										{
+											"handle": [
+												{
+													"handle_response": [
+														{
+															"match": {
+																"status_code": [
+																	2
+																]
+															},
+															"routes": [
+																{
+																	"handle": [
+																		{
+																			"handler": "headers",
+																			"request": {
+																				"set": {
+																					"Remote-Email": [
+																						"{http.reverse_proxy.header.Remote-Email}"
+																					],
+																					"Remote-Groups": [
+																						"{http.reverse_proxy.header.Remote-Groups}"
+																					],
+																					"Remote-Name": [
+																						"{http.reverse_proxy.header.Remote-Name}"
+																					],
+																					"Remote-User": [
+																						"{http.reverse_proxy.header.Remote-User}"
+																					]
+																				}
+																			}
+																		}
+																	]
+																}
+															]
+														},
+														{
+															"routes": [
+																{
+																	"handle": [
+																		{
+																			"exclude": [
+																				"Connection",
+																				"Keep-Alive",
+																				"Te",
+																				"Trailers",
+																				"Transfer-Encoding",
+																				"Upgrade"
+																			],
+																			"handler": "copy_response_headers"
+																		}
+																	]
+																},
+																{
+																	"handle": [
+																		{
+																			"handler": "copy_response"
+																		}
+																	]
+																}
+															]
+														}
+													],
+													"handler": "reverse_proxy",
+													"headers": {
+														"request": {
+															"set": {
+																"X-Forwarded-Method": [
+																	"{http.request.method}"
+																],
+																"X-Forwarded-Uri": [
+																	"{http.request.uri}"
+																]
+															}
+														}
+													},
+													"rewrite": {
+														"method": "GET",
+														"uri": "/api/verify?rd=https://authelia.example.com"
+													},
+													"upstreams": [
+														{
+															"dial": "authelia:9091"
+														}
+													]
+												},
+												{
+													"handler": "reverse_proxy",
+													"upstreams": [
+														{
+															"dial": "backend:8080"
+														}
+													]
+												}
+											]
+										}
+									]
+								}
+							],
+							"terminal": true
+						}
+					]
+				}
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/caddytest/integration/caddyfile_adapt/reverse_proxy_options.txt b/caddytest/integration/caddyfile_adapt/reverse_proxy_options.txt
index e41b900..fc07698 100644
--- a/caddytest/integration/caddyfile_adapt/reverse_proxy_options.txt
+++ b/caddytest/integration/caddyfile_adapt/reverse_proxy_options.txt
@@ -1,11 +1,11 @@
 
 https://example.com {
-	reverse_proxy /path http://localhost:54321 {
-		header_up Host {host}
-		header_up X-Real-IP {remote}
-		header_up X-Forwarded-For {remote}
-		header_up X-Forwarded-Port {server_port}
-		header_up X-Forwarded-Proto "http"
+	reverse_proxy /path https://localhost:54321 {
+		header_up Host {upstream_hostport}
+		header_up Foo bar
+
+		method GET
+		rewrite /rewritten?uri={uri}
 
 		buffer_requests
 
@@ -58,24 +58,19 @@ https://example.com {
 													"headers": {
 														"request": {
 															"set": {
-																"Host": [
-																	"{http.request.host}"
-																],
-																"X-Forwarded-For": [
-																	"{http.request.remote}"
-																],
-																"X-Forwarded-Port": [
-																	"{server_port}"
+																"Foo": [
+																	"bar"
 																],
-																"X-Forwarded-Proto": [
-																	"http"
-																],
-																"X-Real-Ip": [
-																	"{http.request.remote}"
+																"Host": [
+																	"{http.reverse_proxy.upstream.hostport}"
 																]
 															}
 														}
 													},
+													"rewrite": {
+														"method": "GET",
+														"uri": "/rewritten?uri={http.request.uri}"
+													},
 													"transport": {
 														"compression": false,
 														"dial_fallback_delay": 5000000000,
@@ -96,6 +91,7 @@ https://example.com {
 															]
 														},
 														"response_header_timeout": 8000000000,
+														"tls": {},
 														"versions": [
 															"h2c",
 															"2"