2 files changed, 100 insertions, 4 deletions
diff --git a/modules/caddyhttp/headers/caddyfile.go b/modules/caddyhttp/headers/caddyfile.go
new file mode 100644
index 0000000..5eaf064
--- /dev/null
+++ b/modules/caddyhttp/headers/caddyfile.go
@@ -0,0 +1,91 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package headers
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+)
+
+func init() {
+	httpcaddyfile.RegisterHandlerDirective("headers", parseCaddyfile)
+}
+
+// parseCaddyfile sets up the handler from Caddyfile tokens. Syntax:
+//
+//     headers [<matcher>] [[+|-]<field> <value>] {
+//         [+][<field>] [<value>]
+//         [-<field>]
+//     }
+//
+// Either a block can be opened or a single header field can be configured
+// in the first line, but not both in the same directive.
+func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
+	hdr := new(Headers)
+	for h.Next() {
+		// first see if headers are in the initial line
+		var hasArgs bool
+		if h.NextArg() {
+			hasArgs = true
+			field := h.Val()
+			h.NextArg()
+			value := h.Val()
+			processCaddyfileLine(hdr, field, value)
+		}
+
+		// if not, they should be in a block
+		for h.NextBlock() {
+			if hasArgs {
+				return nil, h.Err("cannot specify headers in both arguments and block")
+			}
+			field := h.Val()
+			var value string
+			if h.NextArg() {
+				value = h.Val()
+			}
+			processCaddyfileLine(hdr, field, value)
+		}
+	}
+	return hdr, nil
+}
+
+func processCaddyfileLine(hdr *Headers, field, value string) {
+	if strings.HasPrefix(field, "+") {
+		if hdr.Response == nil {
+			hdr.Response = &RespHeaderOps{HeaderOps: new(HeaderOps)}
+		}
+		if hdr.Response.Add == nil {
+			hdr.Response.Add = make(http.Header)
+		}
+		hdr.Response.Add.Set(field[1:], value)
+	} else if strings.HasPrefix(field, "-") {
+		if hdr.Response == nil {
+			hdr.Response = &RespHeaderOps{HeaderOps: new(HeaderOps)}
+		}
+		hdr.Response.Delete = append(hdr.Response.Delete, field[1:])
+		hdr.Response.Deferred = true
+	} else {
+		if hdr.Response == nil {
+			hdr.Response = &RespHeaderOps{HeaderOps: new(HeaderOps)}
+		}
+		if hdr.Response.Set == nil {
+			hdr.Response.Set = make(http.Header)
+		}
+		hdr.Response.Set.Set(field, value)
+	}
+}
diff --git a/modules/caddyhttp/headers/headers.go b/modules/caddyhttp/headers/headers.go
index 8f4976a..e740004 100644
--- a/modules/caddyhttp/headers/headers.go
+++ b/modules/caddyhttp/headers/headers.go
@@ -23,10 +23,7 @@ import (
 )
 
 func init() {
-	caddy.RegisterModule(caddy.Module{
-		Name: "http.handlers.headers",
-		New:  func() interface{} { return new(Headers) },
-	})
+	caddy.RegisterModule(Headers{})
 }
 
 // Headers is a middleware which can mutate HTTP headers.
@@ -35,6 +32,14 @@ type Headers struct {
 	Response *RespHeaderOps `json:"response,omitempty"`
 }
 
+// CaddyModule returns the Caddy module information.
+func (Headers) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		Name: "http.handlers.headers",
+		New:  func() caddy.Module { return new(Headers) },
+	}
+}
+
 // HeaderOps defines some operations to
 // perform on HTTP headers.
 type HeaderOps struct {