Implement config adapters and beginning of Caddyfile adapter

Along with several other changes, such as renaming caddyhttp.ServerRoute
to caddyhttp.Route, exporting some types that were not exported before,
and tweaking the caddytls TLS values to be more consistent.

Notably, we also now disable automatic cert management for names which
already have a cert (manually) loaded into the cache. These names no
longer need to be specified in the "skip_certificates" field of the
automatic HTTPS config, because they will be skipped automatically.

1 files changed, 29 insertions, 8 deletions

diff --git a/modules/caddyhttp/replacer.go b/modules/caddyhttp/replacer.go
index 439d245..cc29789 100644
--- a/modules/caddyhttp/replacer.go
+++ b/modules/caddyhttp/replacer.go
@@ -15,6 +15,7 @@
 package caddyhttp
 
 import (
+	"fmt"
 	"net"
 	"net/http"
 	"net/textproto"
@@ -28,6 +29,7 @@ import (
 func addHTTPVarsToReplacer(repl caddy.Replacer, req *http.Request, w http.ResponseWriter) {
 	httpVars := func(key string) (string, bool) {
 		if req != nil {
+			// query string parameters
 			if strings.HasPrefix(key, queryReplPrefix) {
 				vals := req.URL.Query()[key[len(queryReplPrefix):]]
 				// always return true, since the query param might
@@ -35,6 +37,7 @@ func addHTTPVarsToReplacer(repl caddy.Replacer, req *http.Request, w http.Respon
 				return strings.Join(vals, ","), true
 			}
 
+			// request header fields
 			if strings.HasPrefix(key, reqHeaderReplPrefix) {
 				field := key[len(reqHeaderReplPrefix):]
 				vals := req.Header[textproto.CanonicalMIMEHeaderKey(field)]
@@ -43,6 +46,7 @@ func addHTTPVarsToReplacer(repl caddy.Replacer, req *http.Request, w http.Respon
 				return strings.Join(vals, ","), true
 			}
 
+			// cookies
 			if strings.HasPrefix(key, cookieReplPrefix) {
 				name := key[len(cookieReplPrefix):]
 				for _, cookie := range req.Cookies() {
@@ -87,14 +91,7 @@ func addHTTPVarsToReplacer(repl caddy.Replacer, req *http.Request, w http.Respon
 				return req.URL.RawQuery, true
 			}
 
-			if strings.HasPrefix(key, respHeaderReplPrefix) {
-				field := key[len(respHeaderReplPrefix):]
-				vals := w.Header()[textproto.CanonicalMIMEHeaderKey(field)]
-				// always return true, since the header field might
-				// be present only in some requests
-				return strings.Join(vals, ","), true
-			}
-
+			// hostname labels
 			if strings.HasPrefix(key, hostLabelReplPrefix) {
 				idxStr := key[len(hostLabelReplPrefix):]
 				idx, err := strconv.Atoi(idxStr)
@@ -111,6 +108,7 @@ func addHTTPVarsToReplacer(repl caddy.Replacer, req *http.Request, w http.Respon
 				return hostLabels[idx], true
 			}
 
+			// path parts
 			if strings.HasPrefix(key, pathPartsReplPrefix) {
 				idxStr := key[len(pathPartsReplPrefix):]
 				idx, err := strconv.Atoi(idxStr)
@@ -129,9 +127,31 @@ func addHTTPVarsToReplacer(repl caddy.Replacer, req *http.Request, w http.Respon
 				}
 				return pathParts[idx], true
 			}
+
+			// middleware variables
+			if strings.HasPrefix(key, varsReplPrefix) {
+				varName := key[len(varsReplPrefix):]
+				tbl := req.Context().Value(VarCtxKey).(map[string]interface{})
+				raw, ok := tbl[varName]
+				if !ok {
+					// variables can be dynamic, so always return true
+					// even when it may not be set; treat as empty
+					return "", true
+				}
+				// do our best to convert it to a string efficiently
+				switch val := raw.(type) {
+				case string:
+					return val, true
+				case fmt.Stringer:
+					return val.String(), true
+				default:
+					return fmt.Sprintf("%s", val), true
+				}
+			}
 		}
 
 		if w != nil {
+			// response header fields
 			if strings.HasPrefix(key, respHeaderReplPrefix) {
 				field := key[len(respHeaderReplPrefix):]
 				vals := w.Header()[textproto.CanonicalMIMEHeaderKey(field)]
@@ -153,5 +173,6 @@ const (
 	cookieReplPrefix     = "http.request.cookie."
 	hostLabelReplPrefix  = "http.request.host.labels."
 	pathPartsReplPrefix  = "http.request.uri.path."
+	varsReplPrefix       = "http.var."
 	respHeaderReplPrefix = "http.response.header."
 )