Add an endpoint to catnip to write the file

Author: mariash

assets/catnip/file/file.go assets/catnip/file/read_file.goassets/catnip/file/file.go renamed to assets/catnip/file/read_file.go

@@ -9,7 +9,7 @@ import (
 	"github.com/go-chi/chi/v5"
 )
 
-func FileHandler(res http.ResponseWriter, req *http.Request) {
+func ReadFileHandler(res http.ResponseWriter, req *http.Request) {
 	filename := chi.URLParam(req, "filename")
 	decodedFilename, err := url.PathUnescape(filename)
 	if err != nil {
@@ -19,13 +19,13 @@ func FileHandler(res http.ResponseWriter, req *http.Request) {
 
 	_, err = os.Stat(decodedFilename)
 	if err != nil {
-		http.Error(res, http.StatusText(404) + ": " + decodedFilename, 404)
+		http.Error(res, http.StatusText(404)+": "+decodedFilename, 404)
 		return
 	}
 
 	content, err := os.ReadFile(decodedFilename)
 	if err != nil {
-		http.Error(res, http.StatusText(500) + ": " + err.Error(), 500)
+		http.Error(res, http.StatusText(500)+": "+err.Error(), 500)
 		return
 	}
 	res.Write(append(content, '\n'))

assets/catnip/file/write_file.go

@@ -0,0 +1,36 @@
+package file
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+
+	"github.com/go-chi/chi/v5"
+)
+
+func WriteFileHandler(res http.ResponseWriter, req *http.Request) {
+	filename := chi.URLParam(req, "filename")
+	decodedFilename, err := url.PathUnescape(filename)
+	if err != nil {
+		http.Error(res, fmt.Sprintf("Cannot unescape file name: %s", filename), http.StatusBadRequest)
+		return
+	}
+
+	decodedFilename = "/" + decodedFilename
+
+	content, err := io.ReadAll(req.Body)
+	if err != nil {
+		http.Error(res, fmt.Sprintf("failed to read the file: %v", err), http.StatusInternalServerError)
+		return
+	}
+
+	err = os.WriteFile(decodedFilename, content, 0644)
+	if err != nil {
+		http.Error(res, http.StatusText(500)+": "+err.Error(), 500)
+		return
+	}
+
+	res.WriteHeader(http.StatusCreated)
+}

assets/catnip/router/router.go

@@ -39,7 +39,8 @@ func New(out io.Writer, clock clock.Clock) *chi.Mux {
 	r.Get("/curl/{host}", linux.CurlHandler)
 	r.Get("/curl/{host}/", linux.CurlHandler)
 	r.Get("/curl/{host}/{port}", linux.CurlHandler)
-	r.Get("/file/{filename}", file.FileHandler)
+	r.Get("/file/{filename}", file.ReadFileHandler)
+	r.Post("/file/{filename}", file.WriteFileHandler)
 
 	return r
 }