From 3f2c3ecf85b590473030b21fd2b5fc9c8ef88744 Mon Sep 17 00:00:00 2001
From: Francis Lavoie <lavofr@gmail.com>
Date: Fri, 17 Sep 2021 10:23:06 -0400
Subject: [PATCH] fastcgi: Implement `try_files` override in Caddyfile
 directive (#4347)

---
 .../php_fastcgi_try_files_override.txt        | 124 ++++++++++++++++++
 .../reverseproxy/fastcgi/caddyfile.go         |  42 ++++--
 2 files changed, 155 insertions(+), 11 deletions(-)
 create mode 100644 caddytest/integration/caddyfile_adapt/php_fastcgi_try_files_override.txt

diff --git a/caddytest/integration/caddyfile_adapt/php_fastcgi_try_files_override.txt b/caddytest/integration/caddyfile_adapt/php_fastcgi_try_files_override.txt
new file mode 100644
index 00000000..2f4ef767
--- /dev/null
+++ b/caddytest/integration/caddyfile_adapt/php_fastcgi_try_files_override.txt
@@ -0,0 +1,124 @@
+:8884
+
+php_fastcgi localhost:9000 {
+	# some php_fastcgi-specific subdirectives
+	split .php .php5
+	env VAR1 value1
+	env VAR2 value2
+	root /var/www
+	try_files {path} {path}/index.php =404
+	dial_timeout 3s
+	read_timeout 10s
+	write_timeout 20s
+
+	# passed through to reverse_proxy (directive order doesn't matter!)
+	lb_policy random
+}
+----------
+{
+	"apps": {
+		"http": {
+			"servers": {
+				"srv0": {
+					"listen": [
+						":8884"
+					],
+					"routes": [
+						{
+							"match": [
+								{
+									"file": {
+										"try_files": [
+											"{http.request.uri.path}/index.php"
+										]
+									},
+									"not": [
+										{
+											"path": [
+												"*/"
+											]
+										}
+									]
+								}
+							],
+							"handle": [
+								{
+									"handler": "static_response",
+									"headers": {
+										"Location": [
+											"{http.request.uri.path}/"
+										]
+									},
+									"status_code": 308
+								}
+							]
+						},
+						{
+							"match": [
+								{
+									"file": {
+										"try_files": [
+											"{http.request.uri.path}",
+											"{http.request.uri.path}/index.php",
+											"=404"
+										],
+										"split_path": [
+											".php",
+											".php5"
+										]
+									}
+								}
+							],
+							"handle": [
+								{
+									"handler": "rewrite",
+									"uri": "{http.matchers.file.relative}"
+								}
+							]
+						},
+						{
+							"match": [
+								{
+									"path": [
+										"*.php",
+										"*.php5"
+									]
+								}
+							],
+							"handle": [
+								{
+									"handler": "reverse_proxy",
+									"load_balancing": {
+										"selection_policy": {
+											"policy": "random"
+										}
+									},
+									"transport": {
+										"dial_timeout": 3000000000,
+										"env": {
+											"VAR1": "value1",
+											"VAR2": "value2"
+										},
+										"protocol": "fastcgi",
+										"read_timeout": 10000000000,
+										"root": "/var/www",
+										"split_path": [
+											".php",
+											".php5"
+										],
+										"write_timeout": 20000000000
+									},
+									"upstreams": [
+										{
+											"dial": "localhost:9000"
+										}
+									]
+								}
+							]
+						}
+					]
+				}
+			}
+		}
+	}
+}
diff --git a/modules/caddyhttp/reverseproxy/fastcgi/caddyfile.go b/modules/caddyhttp/reverseproxy/fastcgi/caddyfile.go
index da1c92d5..1b4cecf4 100644
--- a/modules/caddyhttp/reverseproxy/fastcgi/caddyfile.go
+++ b/modules/caddyhttp/reverseproxy/fastcgi/caddyfile.go
@@ -124,21 +124,22 @@ func (t *Transport) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 //
 // is equivalent to a route consisting of:
 //
+//     # Add trailing slash for directory requests
 //     @canonicalPath {
-//         file {
-//             try_files {path}/index.php
-//         }
-//         not {
-//             path */
-//         }
+//         file {path}/index.php
+//         not path */
 //     }
 //     redir @canonicalPath {path}/ 308
 //
-//     try_files {path} {path}/index.php index.php
-//
-//     @phpFiles {
-//         path *.php
+//     # If the requested file does not exist, try index files
+//     @indexFiles file {
+//         try_files {path} {path}/index.php index.php
+//         split_path .php
 //     }
+//     rewrite @indexFiles {http.matchers.file.relative}
+//
+//     # Proxy PHP files to the FastCGI responder
+//     @phpFiles path *.php
 //     reverse_proxy @phpFiles localhost:7777 {
 //         transport fastcgi {
 //             split .php
@@ -172,6 +173,9 @@ func parsePHPFastCGI(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error
 	// set the default index file for the try_files rewrites
 	indexFile := "index.php"
 
+	// set up for explicitly overriding try_files
+	tryFiles := []string{}
+
 	// if the user specified a matcher token, use that
 	// matcher in a route that wraps both of our routes;
 	// either way, strip the matcher token and pass
@@ -237,6 +241,17 @@ func parsePHPFastCGI(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error
 				}
 				indexFile = args[0]
 
+			case "try_files":
+				args := dispenser.RemainingArgs()
+				dispenser.Delete()
+				for range args {
+					dispenser.Delete()
+				}
+				if len(args) < 1 {
+					return nil, dispenser.ArgErr()
+				}
+				tryFiles = args
+
 			case "resolve_root_symlink":
 				args := dispenser.RemainingArgs()
 				dispenser.Delete()
@@ -318,10 +333,15 @@ func parsePHPFastCGI(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error
 			HandlersRaw:    []json.RawMessage{caddyconfig.JSONModuleObject(redirHandler, "handler", "static_response", nil)},
 		}
 
+		// if tryFiles wasn't overridden, use a reasonable default
+		if len(tryFiles) == 0 {
+			tryFiles = []string{"{http.request.uri.path}", "{http.request.uri.path}/" + indexFile, indexFile}
+		}
+
 		// route to rewrite to PHP index file
 		rewriteMatcherSet := caddy.ModuleMap{
 			"file": h.JSON(fileserver.MatchFile{
-				TryFiles:  []string{"{http.request.uri.path}", "{http.request.uri.path}/" + indexFile, indexFile},
+				TryFiles:  tryFiles,
 				SplitPath: extensions,
 			}),
 		}