Added Static File Handler (#674)

gofr-dev · Jun 26, 2024 · cd5b92e · cd5b92e
1 parent f10b5c5
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diff --git a/docs/advanced-guide/serving-static-files/page.md b/docs/advanced-guide/serving-static-files/page.md
@@ -0,0 +1,75 @@
+# Serving Static Files using GoFr
+
+Often, we are required to serve static content such as a default profile image, a favicon, or a background image for our 
+web application. We want to have a mechanism to serve that static content without the hassle of implementing it from scratch.
+
+GoFr provides a default mechanism where if a `static` folder is available in the directory of the application,
+it automatically provides an endpoint with `/static/<filename>`, here filename refers to the file we want to get static content to be served. 
+
+Example project structure:
+
+```dotenv
+project_folder
+|
+|---configs
+|       .env
+|---static
+|       img1.jpeg
+|       img2.png
+|       img3.jpeg
+|   main.go
+|   main_test.go
+```
+
+main.go code:
+
+```go
+package main
+
+import "gofr.dev/pkg/gofr"
+
+func main(){
+    app := gofr.New()
+    app.Run()
+}
+```
+
+Additionally, if we want to serve more static endpoints, we have a dedicated function called `AddStaticFiles()`
+which takes 2 parameters `endpoint` and the `filepath` of the static folder which we want to serve.
+
+Example project structure:
+
+```dotenv
+project_folder
+|
+|---configs
+|       .env
+|---static
+|       img1.jpeg
+|       img2.png
+|       img3.jpeg
+|---public
+|       |---css
+|       |       main.css
+|       |---js
+|       |       main.js
+|       |   index.html
+|   main.go
+|   main_test.go
+```
+
+main.go file:
+
+```go
+package main
+
+import "gofr.dev/pkg/gofr"
+
+func main(){
+    app := gofr.New()
+    app.AddStaticFiles("public", "./public")
+    app.Run()
+}
+```
+
+In the above example, both endpoints `/public` and `/static` are available for the app to render the static content.
diff --git a/pkg/gofr/gofr.go b/pkg/gofr/gofr.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
@@ -30,6 +31,8 @@ import (
 	"gofr.dev/pkg/gofr/service"
 )
 
+const defaultPublicStaticDir = "static"
+
 // App is the main application in the GoFr framework.
 type App struct {
 	// Config can be used by applications to fetch custom configurations from environment or file.
@@ -92,6 +95,14 @@ func New() *App {
 
 	app.subscriptionManager = newSubscriptionManager(app.container)
 
+	// static fileserver
+	currentWd, _ := os.Getwd()
+	checkDirectory := filepath.Join(currentWd, defaultPublicStaticDir)
+
+	if _, err = os.Stat(checkDirectory); err == nil {
+		app.AddStaticFiles(defaultPublicStaticDir, checkDirectory)
+	}
+
 	return app
 }
 
@@ -439,3 +450,22 @@ func contains(elems []string, v string) bool {
 
 	return false
 }
+
+func (a *App) AddStaticFiles(endpoint, filePath string) {
+	a.httpRegistered = true
+
+	// update file path based on current directory if it starts with ./
+	if strings.HasPrefix(filePath, "./") {
+		currentWorkingDir, _ := os.Getwd()
+		filePath = filepath.Join(currentWorkingDir, filePath)
+	}
+
+	endpoint = "/" + strings.TrimPrefix(endpoint, "/")
+
+	if _, err := os.Stat(filePath); err != nil {
+		a.container.Logger.Errorf("error in registering '%s' static endpoint, error: %v", endpoint, err)
+		return
+	}
+
+	a.httpServer.router.AddStaticFiles(endpoint, filePath)
+}
diff --git a/pkg/gofr/gofr_test.go b/pkg/gofr/gofr_test.go
@@ -561,3 +561,141 @@ func Test_AddCronJob_Success(t *testing.T) {
 
 	assert.Truef(t, pass, "unable to add cron job to cron table")
 }
+
+func TestStaticHandler(t *testing.T) {
+	const indexHTML = "indexTest.html"
+
+	// Generating some files for testing
+	htmlContent := []byte("<html><head><title>Test Static File</title></head><body><p>Testing Static File</p></body></html>")
+
+	createPublicDirectory(t, defaultPublicStaticDir, htmlContent)
+
+	defer os.Remove("static/indexTest.html")
+
+	createPublicDirectory(t, "testdir", htmlContent)
+
+	defer os.RemoveAll("testdir")
+
+	app := New()
+
+	app.AddStaticFiles("gofrTest", "./testdir")
+
+	app.httpRegistered = true
+	app.httpServer.port = 8022
+
+	go app.Run()
+	time.Sleep(1 * time.Second)
+
+	host := "http://localhost:8022"
+
+	tests := []struct {
+		desc                       string
+		method                     string
+		path                       string
+		statusCode                 int
+		expectedBody               string
+		expectedBodyLength         int
+		expectedResponseHeaderType string
+	}{
+		{
+			desc: "check file content index.html", method: http.MethodGet, path: "/" + defaultPublicStaticDir + "/" + indexHTML,
+			statusCode: http.StatusOK, expectedBodyLength: len(htmlContent),
+			expectedResponseHeaderType: "text/html; charset=utf-8", expectedBody: string(htmlContent),
+		},
+		{
+			desc: "check public endpoint", method: http.MethodGet,
+			path: "/" + defaultPublicStaticDir, statusCode: http.StatusNotFound,
+		},
+		{
+			desc: "check file content index.html in custom dir", method: http.MethodGet, path: "/" + "gofrTest" + "/" + indexHTML,
+			statusCode: http.StatusOK, expectedBodyLength: len(htmlContent),
+			expectedResponseHeaderType: "text/html; charset=utf-8", expectedBody: string(htmlContent),
+		},
+		{
+			desc: "check public endpoint in custom dir", method: http.MethodGet, path: "/" + "gofrTest",
+			statusCode: http.StatusNotFound,
+		},
+	}
+
+	for i, tc := range tests {
+		request, err := http.NewRequestWithContext(context.Background(), tc.method, host+tc.path, http.NoBody)
+		if err != nil {
+			t.Fatalf("TEST[%d], Failed to create request, error: %s", i, err)
+		}
+
+		request.Header.Set("Content-Type", "application/json")
+
+		client := http.Client{}
+
+		resp, err := client.Do(request)
+		if err != nil {
+			t.Fatalf("TEST[%d], Request failed, error: %s", i, err)
+		}
+
+		bodyBytes, err := io.ReadAll(resp.Body)
+		if err != nil {
+			t.Fatalf("TEST[%d], Failed to read response body, error: %s", i, err)
+		}
+
+		body := string(bodyBytes)
+
+		assert.NoError(t, err, "TEST[%d], Failed.\n%s", i, tc.desc)
+		assert.Equal(t, tc.statusCode, resp.StatusCode, "TEST[%d], Failed with Status Body.\n%s", i, tc.desc)
+
+		if tc.expectedBody != "" {
+			assert.Contains(t, body, tc.expectedBody, "TEST[%d], Failed with Expected Body.\n%s", i, tc.desc)
+		}
+
+		if tc.expectedBodyLength != 0 {
+			contentLength := resp.Header.Get("Content-Length")
+			assert.Equal(t, strconv.Itoa(tc.expectedBodyLength), contentLength, "TEST[%d], Failed at Content-Length.\n%s", i, tc.desc)
+		}
+
+		if tc.expectedResponseHeaderType != "" {
+			assert.Equal(t,
+				tc.expectedResponseHeaderType,
+				resp.Header.Get("Content-Type"),
+				"TEST[%d], Failed at Expected Content-Type.\n%s", i, tc.desc)
+		}
+
+		resp.Body.Close()
+	}
+}
+
+func TestStaticHandlerInvalidFilePath(t *testing.T) {
+	// Generating some files for testing
+	logs := testutil.StderrOutputForFunc(func() {
+		app := New()
+
+		app.AddStaticFiles("gofrTest", ".//,.!@#$%^&")
+	})
+
+	assert.Contains(t, logs, "no such file or directory")
+	assert.Contains(t, logs, "error in registering '/gofrTest' static endpoint")
+}
+
+func createPublicDirectory(t *testing.T, defaultPublicStaticDir string, htmlContent []byte) {
+	t.Helper()
+
+	const indexHTML = "indexTest.html"
+
+	directory := "./" + defaultPublicStaticDir
+	if _, err := os.Stat(directory); err != nil {
+		if err = os.Mkdir("./"+defaultPublicStaticDir, os.ModePerm); err != nil {
+			t.Fatalf("Couldn't create a "+defaultPublicStaticDir+" directory, error: %s", err)
+		}
+	}
+
+	file, err := os.Create(filepath.Join(directory, indexHTML))
+
+	if err != nil {
+		t.Fatalf("Couldn't create %s file", indexHTML)
+	}
+
+	_, err = file.Write(htmlContent)
+	if err != nil {
+		t.Fatalf("Couldn't write to %s file", indexHTML)
+	}
+
+	file.Close()
+}
diff --git a/pkg/gofr/http/router.go b/pkg/gofr/http/router.go
@@ -2,10 +2,12 @@ package http
 
 import (
 	"net/http"
-
-	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/gorilla/mux"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 // Router is responsible for routing HTTP request.
@@ -45,3 +47,36 @@ func (rou *Router) UseMiddleware(mws ...Middleware) {
 
 	rou.Use(middlewares...)
 }
+
+type staticFileConfig struct {
+	directoryName string
+}
+
+func (rou *Router) AddStaticFiles(endpoint, dirName string) {
+	cfg := staticFileConfig{directoryName: dirName}
+
+	fileServer := http.FileServer(http.Dir(cfg.directoryName))
+	rou.Router.NewRoute().PathPrefix(endpoint + "/").Handler(http.StripPrefix(endpoint, cfg.staticHandler(fileServer)))
+}
+
+func (staticConfig staticFileConfig) staticHandler(fileServer http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		url := r.URL.Path
+
+		filePath := strings.Split(url, "/")
+
+		fileName := filePath[len(filePath)-1]
+
+		const defaultSwaggerFileName = "openapi.json"
+
+		if _, err := os.Stat(filepath.Join(staticConfig.directoryName, url)); fileName == defaultSwaggerFileName && err == nil {
+			w.WriteHeader(http.StatusForbidden)
+
+			_, _ = w.Write([]byte("403 forbidden"))
+
+			return
+		}
+
+		fileServer.ServeHTTP(w, r)
+	})
+}