1 files changed, 127 insertions, 0 deletions
diff --git a/internal/handlers/static.go b/internal/handlers/static.go
new file mode 100644
index 0000000..b27fa1a
--- /dev/null
+++ b/internal/handlers/static.go
@@ -0,0 +1,127 @@
+// Copyright 2018 ThousandEyes Inc.
+//
+// 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 handlers
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"sort"
+)
+
+// StaticConfigFileHandler handles static config files
+type StaticConfigFileHandler struct{}
+
+func (s *StaticConfigFileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	env := envFromRequest(r)
+	envName := envNameFromRequest(r)
+	basePath := path.Join(env.DataDir, "static")
+	if envName == "" {
+		http.FileServer(http.Dir(basePath)).ServeHTTP(w, r)
+		return
+	}
+	envPath := filepath.Join(env.DataDir, env.EnvDir, envName, "static")
+	OverlayFileServer(envPath, basePath).ServeHTTP(w, r)
+}
+
+// StaticConfigFileServer returns a StaticConfigFileHandler instance implementing http.Handler
+func StaticConfigFileServer() *StaticConfigFileHandler {
+	return &StaticConfigFileHandler{}
+}
+
+// OverlayFileServerHandler handles request for overlayer directories
+type OverlayFileServerHandler struct {
+	upper string
+	lower string
+}
+
+// OverlayFileServer serves static content from two overlayed directories
+func OverlayFileServer(upper, lower string) *OverlayFileServerHandler {
+	return &OverlayFileServerHandler{
+		upper: upper,
+		lower: lower,
+	}
+}
+
+func (o *OverlayFileServerHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+
+	fp := filepath.Clean(r.URL.Path)
+	upper := filepath.Clean(path.Join(o.upper, fp))
+	lower := filepath.Clean(path.Join(o.lower, fp))
+
+	// TODO: try to avoid stat()-ing both if not necessary
+	infoUpper, errUpper := os.Stat(upper)
+	infoLower, errLower := os.Stat(lower)
+
+	// If both upper and lower files/dirs do not exist, return 404
+	if errUpper != nil && os.IsNotExist(errUpper) &&
+		errLower != nil && os.IsNotExist(errLower) {
+		http.NotFound(w, r)
+		return
+	}
+
+	isDir := false
+	fileList := make(map[string]os.FileInfo)
+
+	if errUpper == nil && infoUpper.IsDir() {
+		files, _ := ioutil.ReadDir(upper)
+		for _, f := range files {
+			fileList[f.Name()] = f
+		}
+		isDir = true
+	}
+	if errLower == nil && infoLower.IsDir() {
+		files, _ := ioutil.ReadDir(lower)
+		for _, f := range files {
+			if _, ok := fileList[f.Name()]; !ok {
+				fileList[f.Name()] = f
+			}
+		}
+		isDir = true
+	}
+
+	// Generate HTML directory index
+	if isDir {
+		fileListIndex := []string{}
+		for i := range fileList {
+			fileListIndex = append(fileListIndex, i)
+		}
+		sort.Strings(fileListIndex)
+		w.Write([]byte("<pre>\n"))
+		for _, i := range fileListIndex {
+			f := fileList[i]
+			name := f.Name()
+			if f.IsDir() {
+				name = name + "/"
+			}
+			l := fmt.Sprintf("<a href=\"%s\">%s</a>\n", name, name)
+			w.Write([]byte(l))
+		}
+		w.Write([]byte("</pre>\n"))
+		return
+	}
+
+	// Serve the file from the upper layer if it exists.
+	if errUpper == nil {
+		http.ServeFile(w, r, upper)
+		// If not serve it from the lower
+	} else if errLower == nil {
+		http.ServeFile(w, r, lower)
+	}
+	http.NotFound(w, r)
+}