Merge pull request #36 from demipel8/master

CORS support

Dockerfile

@@ -3,7 +3,7 @@
 ################################################################################
 FROM golang:1.13.1 as builder
 
-ENV VERSION 1.6.6
+ENV VERSION 1.7.6
 ENV BUILD_DIR /build
 
 RUN mkdir -p ${BUILD_DIR}

Dockerfile.all

@@ -1,6 +1,6 @@
 FROM golang:1.13.1 as builder
 
-ENV VERSION 1.6.6
+ENV VERSION 1.7.6
 ENV BUILD_DIR /build
 
 RUN mkdir -p ${BUILD_DIR}
@@ -21,5 +21,5 @@ LABEL life.apets.vendor="Halverneus" \
       life.apets.url="https://github.com/halverneus/static-file-server" \
       life.apets.name="Static File Server" \
       life.apets.description="A tiny static file server" \
-      life.apets.version="v1.6.6" \
+      life.apets.version="v1.7.6" \
       life.apets.schema-version="1.0"

README.md

@@ -14,6 +14,9 @@ Install from any of the following locations:
 Default values are shown with the associated environment variable.
 
 ```bash
+# Enables resource access from any domain.
+CORS=false
+
 # Enable debugging for troubleshooting. If set to 'true' this prints extra
 # information during execution. IMPORTANT NOTE: The configuration summary is
 # printed to stdout while logs generated during execution are printed to stderr.
@@ -69,6 +72,7 @@ show-listing: true
 tls-cert: ""
 tls-key: ""
 url-prefix: ""
+cors: false
 ```
 
 Example configuration with possible alternative values:

cli/help/help.go

@@ -33,6 +33,10 @@ DEPENDENCIES
     None... not even libc!
 
 ENVIRONMENT VARIABLES
+    CORS
+        When set to 'true' it enables resource access from any domain. All responses
+        will include the headers 'Access-Control-Allow-Origin' and 'Access-Control-Allow-Headers'
+        with a wildcard value ('*').
     DEBUG
         When set to 'true' enables additional logging, including the
         configuration used and an access log for each request. IMPORTANT NOTE:
@@ -94,6 +98,7 @@ CONFIGURATION FILE
     tls-cert: ""
     tls-key: ""
     url-prefix: ""
+    cors: false
     ----------------------------------------------------------------------------
 
     Example config.yml with possible alternative values:

cli/server/server.go

@@ -61,6 +61,11 @@ func handlerSelector() (handler http.HandlerFunc) {
 	if !config.Get.ShowListing {
 		handler = handle.IgnoreIndex(handler)
 	}
+
+	if config.Get.Cors {
+		handler = handle.AddCorsHeaders(handler)
+	}
+
 	return
 }
 

cli/server/server_test.go

@@ -42,23 +42,28 @@ func TestHandlerSelector(t *testing.T) {
 		listing bool
 		debug   bool
 		refer   []string
+		cors    bool
 	}{
-		{"Basic handler w/o debug", testFolder, "", true, false, ignoreReferrer},
+		{"Basic handler w/o debug", testFolder, "", true, false, ignoreReferrer, false},
-		{"Prefix handler w/o debug", testFolder, testPrefix, true, false, ignoreReferrer},
+		{"Prefix handler w/o debug", testFolder, testPrefix, true, false, ignoreReferrer, false},
-		{"Basic and hide listing handler w/o debug", testFolder, "", false, false, ignoreReferrer},
+		{"Basic and hide listing handler w/o debug", testFolder, "", false, false, ignoreReferrer, false},
-		{"Prefix and hide listing handler w/o debug", testFolder, testPrefix, false, false, ignoreReferrer},
+		{"Prefix and hide listing handler w/o debug", testFolder, testPrefix, false, false, ignoreReferrer, false},
-		{"Basic handler w/debug", testFolder, "", true, true, ignoreReferrer},
+		{"Basic handler w/debug", testFolder, "", true, true, ignoreReferrer, false},
-		{"Prefix handler w/debug", testFolder, testPrefix, true, true, ignoreReferrer},
+		{"Prefix handler w/debug", testFolder, testPrefix, true, true, ignoreReferrer, false},
-		{"Basic and hide listing handler w/debug", testFolder, "", false, true, ignoreReferrer},
+		{"Basic and hide listing handler w/debug", testFolder, "", false, true, ignoreReferrer, false},
-		{"Prefix and hide listing handler w/debug", testFolder, testPrefix, false, true, ignoreReferrer},
+		{"Prefix and hide listing handler w/debug", testFolder, testPrefix, false, true, ignoreReferrer, false},
-		{"Basic handler w/o debug w/refer", testFolder, "", true, false, testReferrer},
+		{"Basic handler w/o debug w/refer", testFolder, "", true, false, testReferrer, false},
-		{"Prefix handler w/o debug w/refer", testFolder, testPrefix, true, false, testReferrer},
+		{"Prefix handler w/o debug w/refer", testFolder, testPrefix, true, false, testReferrer, false},
-		{"Basic and hide listing handler w/o debug w/refer", testFolder, "", false, false, testReferrer},
+		{"Basic and hide listing handler w/o debug w/refer", testFolder, "", false, false, testReferrer, false},
-		{"Prefix and hide listing handler w/o debug w/refer", testFolder, testPrefix, false, false, testReferrer},
+		{"Prefix and hide listing handler w/o debug w/refer", testFolder, testPrefix, false, false, testReferrer, false},
-		{"Basic handler w/debug w/refer", testFolder, "", true, true, testReferrer},
+		{"Basic handler w/debug w/refer w/o cors", testFolder, "", true, true, testReferrer, false},
-		{"Prefix handler w/debug w/refer", testFolder, testPrefix, true, true, testReferrer},
+		{"Prefix handler w/debug w/refer w/o cors", testFolder, testPrefix, true, true, testReferrer, false},
-		{"Basic and hide listing handler w/debug w/refer", testFolder, "", false, true, testReferrer},
+		{"Basic and hide listing handler w/debug w/refer w/o cors", testFolder, "", false, true, testReferrer, false},
-		{"Prefix and hide listing handler w/debug w/refer", testFolder, testPrefix, false, true, testReferrer},
+		{"Prefix and hide listing handler w/debug w/refer w/o cors", testFolder, testPrefix, false, true, testReferrer, false},
+		{"Basic handler w/debug w/refer w/cors", testFolder, "", true, true, testReferrer, true},
+		{"Prefix handler w/debug w/refer w/cors", testFolder, testPrefix, true, true, testReferrer, true},
+		{"Basic and hide listing handler w/debug w/refer w/cors", testFolder, "", false, true, testReferrer, true},
+		{"Prefix and hide listing handler w/debug w/refer w/cors", testFolder, testPrefix, false, true, testReferrer, true},
 	}
 
 	for _, tc := range testCases {
@@ -68,6 +73,7 @@ func TestHandlerSelector(t *testing.T) {
 			config.Get.ShowListing = tc.listing
 			config.Get.URLPrefix = tc.prefix
 			config.Get.Referrers = tc.refer
+			config.Get.Cors = tc.cors
 
 			handlerSelector()
 		})

config/config.go

@@ -23,6 +23,7 @@ var (
 		TLSKey      string   `yaml:"tls-key"`
 		URLPrefix   string   `yaml:"url-prefix"`
 		Referrers   []string `yaml:"referrers"`
+		Cors		bool     `yaml:cors`
 	}
 )
 
@@ -36,6 +37,7 @@ const (
 	tlsCertKey     = "TLS_CERT"
 	tlsKeyKey      = "TLS_KEY"
 	urlPrefixKey   = "URL_PREFIX"
+	corsKey        = "CORS"
 )
 
 var (
@@ -48,6 +50,7 @@ var (
 	defaultTLSCert     = ""
 	defaultTLSKey      = ""
 	defaultURLPrefix   = ""
+	defaultCors        = false
 )
 
 func init() {
@@ -65,6 +68,7 @@ func setDefaults() {
 	Get.TLSCert = defaultTLSCert
 	Get.TLSKey = defaultTLSKey
 	Get.URLPrefix = defaultURLPrefix
+	Get.Cors = defaultCors
 }
 
 // Load the configuration file.
@@ -113,6 +117,7 @@ func overrideWithEnvVars() {
 	Get.TLSKey = envAsStr(tlsKeyKey, Get.TLSKey)
 	Get.URLPrefix = envAsStr(urlPrefixKey, Get.URLPrefix)
 	Get.Referrers = envAsStrSlice(referrersKey, Get.Referrers)
+	Get.Cors = envAsBool(corsKey, Get.Cors)
 }
 
 // validate the configuration.

handle/handle.go

@@ -109,6 +109,15 @@ func IgnoreIndex(serve http.HandlerFunc) http.HandlerFunc {
 	}
 }
 
+func AddCorsHeaders(serve http.HandlerFunc) http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		writer.Header().Set("Access-Control-Allow-Origin", "*")
+		writer.Header().Set("Access-Control-Allow-Headers", "*")
+
+		serve(writer, request)
+	}
+}
+
 // Listening function for serving the handler function.
 func Listening() ListenerFunc {
 	return func(binding string, handler http.HandlerFunc) error {

handle/handle_test.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"path"
 	"testing"
+	"strings"
 )
 
 var (
@@ -458,3 +459,32 @@ func TestValidReferrer(t *testing.T) {
 		})
 	}
 }
+
+func TestAddsCorsHeaders(t *testing.T) {
+	testCases := []struct {
+		name     string
+		header   string
+		value    string
+	}{
+		{"Add Access-Control-Allow-Origin header", "Access-Control-Allow-Origin", "*"},
+		{"Add Access-Control-Allow-Headers header", "Access-Control-Allow-Headers", "*"},
+	}
+
+	for _, serveFile := range serveFileFuncs {
+		handler := AddCorsHeaders(Basic(serveFile, baseDir))
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				req := httptest.NewRequest("GET", "http://localhost/", nil)
+				w := httptest.NewRecorder()
+
+				handler(w, req)
+
+				resp := w.Result()
+				headerValue := strings.Join(resp.Header[tc.header], ", ")
+				if headerValue != tc.value {
+					t.Errorf("Response header %q = %q, want %q", tc.header, headerValue, tc.value)
+				}
+			})
+		}
+	}
+}