From 6804ff6b4360543d25859f5693da43ecc8cb31be Mon Sep 17 00:00:00 2001
From: Clinton Ebadi <clinton@unknownlamer.org>
Date: Sat, 27 Apr 2019 18:48:52 -0400
Subject: [PATCH] apache: generalize localProxyRewrite into proxyRewrite

Allow use of any proxy target instead of localhost (which has not had
any use at hcoop for several years since we moved member logins/daemon
to a server separate from apache), and allow passing rewrite
flags. Apache will accept any combination of rewrite flags, despite
all combinations not making any sense.
---
 lib/mod_rewrite.dtl    | 11 ++++++-----
 src/plugins/apache.sml | 23 ++++++++++++++++-------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/lib/mod_rewrite.dtl b/lib/mod_rewrite.dtl
index ce0436c..b4255dc 100644
--- a/lib/mod_rewrite.dtl
+++ b/lib/mod_rewrite.dtl
@@ -63,11 +63,12 @@ extern val rewriteBase : no_spaces -> [Location];
 extern type proxy_port;
 {{A port number above 1024}}
 
-extern val localProxyRewrite : no_spaces -> no_spaces -> proxy_port -> [^Vhost];
-{{All requests matching the regular expression in the first argument are
-  redirected to another HTTPD running on localhost at the given port, generating
-  the new URI by substituting variables in the second argument as per Apache
-  mod_rewrite.}}
+extern val proxyRewrite : regexp -> proxy_reverse_target -> no_spaces -> [mod_rewrite_flag] -> [^Vhost];
+{{Safe wrapper around mod_rewrite proxy flag. All requests matching
+  the regular expression in the first argument are proxied to the host
+  specified in the second argument, appending a new URI by
+  substituting variables in the third argument as per Apache
+  mod_rewrite. Additional rewrite flags may be specified.}}
 
 extern type mod_rewrite_trace_level;
 {{A mod_rewrite log level, between 0 and 8. 2 or 3 are useful for
diff --git a/src/plugins/apache.sml b/src/plugins/apache.sml
index f21d3ac..a490419 100644
--- a/src/plugins/apache.sml
+++ b/src/plugins/apache.sml
@@ -664,17 +664,26 @@ fun checkExpires () =
 	(write "\tExpiresActive on\n";
 	 expiresEnabled := true)
 
-val () = Env.action_three "localProxyRewrite"
-	 ("from", Env.string, "to", Env.string, "port", Env.int)
-	 (fn (from, to, port) =>
+val () = Env.action_four "proxyRewrite"
+	 ("from", Env.string, "tohost", Env.string, "to", Env.string, "flags", Env.list flag)
+	 (fn (from, tohost, to, flags) =>
 	     (checkRewrite ();
 	      write "\tRewriteRule\t\"";
 	      write from;
-	      write "\"\thttp://localhost:";
-	      write (Int.toString port);
-	      write "/";
+	      write "\"\t\"";
+	      write tohost;
+	      write "/"; (* ensure rewrite rule can't change port *)
 	      write to;
-	      write " [P]\n"))
+	      write "\"";
+	      write " [P";
+	      case flags of
+		  [] => ()
+		| flag::rest => (write ",";
+				 write flag;
+				 app (fn flag => (write ",";
+						  write flag)) rest);
+
+	      write "]\n"))
 
 val () = Env.action_four "expiresByType"
 	 ("mime", Env.string, "base", interval_base, "num", Env.int, "inter", interval)
-- 
2.20.1