admin: Support config adapters at /load endpoint

Based on Content-Type

admin.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"net"
 	"net/http"
@@ -29,6 +30,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/caddyserver/caddy/caddyconfig"
 	"github.com/mholt/certmagic"
 	"github.com/rs/cors"
 )
@@ -164,12 +166,45 @@ func handleLoadConfig(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if !strings.Contains(r.Header.Get("Content-Type"), "/json") {
-		http.Error(w, "unacceptable Content-Type", http.StatusBadRequest)
-		return
+	var payload io.Reader = r.Body
+
+	// if the config is formatted other than Caddy's native
+	// JSON, we need to adapt it before loading it
+	ct := r.Header.Get("Content-Type")
+	if !strings.Contains(ct, "/json") {
+		slashIdx := strings.Index(ct, "/")
+		if slashIdx < 0 {
+			http.Error(w, "Malformed Content-Type", http.StatusBadRequest)
+			return
+		}
+		adapterName := ct[slashIdx+1:]
+		cfgAdapter := caddyconfig.GetAdapter(adapterName)
+		if cfgAdapter == nil {
+			http.Error(w, "Unrecognized config adapter: "+adapterName, http.StatusBadRequest)
+			return
+		}
+		body, err := ioutil.ReadAll(http.MaxBytesReader(w, r.Body, 1024*1024))
+		if err != nil {
+			http.Error(w, "Error reading request body: "+err.Error(), http.StatusBadRequest)
+			return
+		}
+		result, warnings, err := cfgAdapter.Adapt(body, nil)
+		if err != nil {
+			log.Printf("[ADMIN][ERROR] adapting config from %s: %v", adapterName, err)
+			http.Error(w, fmt.Sprintf("Adapting config from %s: %v", adapterName, err), http.StatusBadRequest)
+			return
+		}
+		if len(warnings) > 0 {
+			respBody, err := json.Marshal(warnings)
+			if err != nil {
+				log.Printf("[ADMIN][ERROR] marshaling warnings: %v", err)
+			}
+			w.Write(respBody)
+		}
+		payload = bytes.NewReader(result)
 	}
 
-	err := Load(r.Body)
+	err := Load(payload)
 	if err != nil {
 		log.Printf("[ADMIN][ERROR] loading config: %v", err)
 		http.Error(w, err.Error(), http.StatusBadRequest)

caddyconfig/configadapters.go

@@ -98,6 +98,8 @@ func JSONIndent(val interface{}) ([]byte, error) {
 	return json.MarshalIndent(val, "", "\t")
 }
 
+// RegisterAdapter registers a config adapter with the given name.
+// This should usually be done at init-time.
 func RegisterAdapter(name string, adapter Adapter) error {
 	if _, ok := configAdapters[name]; ok {
 		return fmt.Errorf("%s: already registered", name)
@@ -106,6 +108,8 @@ func RegisterAdapter(name string, adapter Adapter) error {
 	return nil
 }
 
+// GetAdapter returns the adapter with the given name,
+// or nil if one with that name is not registered.
 func GetAdapter(name string) Adapter {
 	return configAdapters[name]
 }