make header operations more flexible... needs testing

3 files changed, 72 insertions, 12 deletions

diff --git a/src/daq/s5proxy/sample.json b/src/daq/s5proxy/sample.json
index 1339fbf..7f5ac66 100644
--- a/src/daq/s5proxy/sample.json
+++ b/src/daq/s5proxy/sample.json
@@ -7,7 +7,9 @@
         "X-hello": "world",
         "X-verr": "stefan"
     },
-    "response_header": {
-        "Cache-Control":  "no-cache"
-    }
+    "response_header": [
+        { "op": "set", "header": "Cache-Control", "value": "no-cache" },
+        { "op": "add", "header": "Cache-Control", "value": "no-store" },
+        { "op": "add", "header": "Cache-Control", "value": "must-revalidate" }
+    ]
 }
diff --git a/src/daq/s5proxy/src/s5proxy/config.go b/src/daq/s5proxy/src/s5proxy/config.go
index bffb672..ec7e467 100644
--- a/src/daq/s5proxy/src/s5proxy/config.go
+++ b/src/daq/s5proxy/src/s5proxy/config.go
@@ -37,13 +37,60 @@ import (
 	"os"
 )
 
+type Operation uint
+
+const (
+	OpAdd Operation = iota
+	OpDel
+	OpSet
+)
+
+func (o Operation) String() string {
+	switch o {
+	case OpAdd:
+		return "add"
+	case OpDel:
+		return "del"
+	case OpSet:
+		return "set"
+	}
+	return "unknown"
+}
+
+func (o *Operation) fromString(str string) (err error) {
+	switch str {
+	case "add":
+		*o = OpAdd
+	case "del":
+		*o = OpDel
+	case "set":
+		*o = OpSet
+	}
+	return
+}
+
+func (o Operation) MarshalText() (data []byte, err error) {
+	data = []byte(o.String())
+	return
+}
+
+func (o *Operation) UnmarshalJSON(data []byte) (err error) {
+	return o.fromString(string(data))
+}
+
+type HeaderOperation struct {
+	Header    string    `json:"header"`
+	Value     string    `json:"value"`
+	Operation Operation `json:"op"`
+}
+
 type Config struct {
 	ListenAddr     string            `json:"listen"`
 	ConnectAddr    string            `json:"connect"`
 	CertFile       string            `json:"cert"`
 	KeyFile        string            `json:"key"`
-	RequestHeader  map[string]string `json:"request_header"`
-	ResponseHeader map[string]string `json:"response_header"`
+	RequestHeader  []HeaderOperation `json:"request_header"`
+	ResponseHeader []HeaderOperation `json:"response_header"`
 }
 
 func readConfig(configfile string) (conf *Config, err error) {
@@ -56,9 +103,6 @@ func readConfig(configfile string) (conf *Config, err error) {
 	defer f.Close()
 
 	conf = &Config{}
-	conf.RequestHeader = make(map[string]string)
-	conf.ResponseHeader = make(map[string]string)
-
 	err = json.NewDecoder(f).Decode(conf)
 	return
 }
diff --git a/src/daq/s5proxy/src/s5proxy/proxy.go b/src/daq/s5proxy/src/s5proxy/proxy.go
index d1fb892..282d502 100644
--- a/src/daq/s5proxy/src/s5proxy/proxy.go
+++ b/src/daq/s5proxy/src/s5proxy/proxy.go
@@ -53,8 +53,15 @@ func (r s5proxyResponseWriter) Write(data []byte) (int, error) {
 }
 
 func (r s5proxyResponseWriter) WriteHeader(status int) {
-	for hdr, value := range r.conf.ResponseHeader {
-		r.wrapped.Header().Set(hdr, value)
+	for _, h := range r.conf.ResponseHeader {
+		switch h.Operation {
+		case OpAdd:
+			r.wrapped.Header().Add(h.Header, h.Value)
+		case OpDel:
+			r.wrapped.Header().Del(h.Header)
+		case OpSet:
+			r.wrapped.Header().Set(h.Header, h.Value)
+		}
 	}
 	r.wrapped.WriteHeader(status)
 }
@@ -74,8 +81,15 @@ func s5proxyInit(conf *Config) (m *http.ServeMux, err error) {
 
 	p.Director = func(req *http.Request) {
 		origDir(req)
-		for hdr, value := range conf.RequestHeader {
-			req.Header.Set(hdr, value)
+		for _, h := range conf.RequestHeader {
+			switch h.Operation {
+			case OpAdd:
+				req.Header.Add(h.Header, h.Value)
+			case OpDel:
+				req.Header.Del(h.Header)
+			case OpSet:
+				req.Header.Set(h.Header, h.Value)
+			}
 		}
 	}