github.com/bazelbuild/rules_webtesting@v0.2.0/go/wsl/upload/upload.go (about)

     1  // Copyright 2018 Google Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package files handles file uploads and downloads.
    16  package upload
    17  
    18  import (
    19  	"archive/zip"
    20  	"bytes"
    21  	"encoding/base64"
    22  	"encoding/json"
    23  	"io"
    24  	"io/ioutil"
    25  	"net/http"
    26  	"os"
    27  	"path/filepath"
    28  	"strings"
    29  
    30  	"github.com/bazelbuild/rules_webtesting/go/httphelper"
    31  )
    32  
    33  type Uploader struct {
    34  	Root string
    35  }
    36  
    37  func (u *Uploader) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    38  	if r.Method == http.MethodGet || r.Method == http.MethodDelete {
    39  		errorResponse(w, http.StatusMethodNotAllowed, 9, "unknown method", "file deletion and fetching is not allowed")
    40  		return
    41  	}
    42  
    43  	reqJSON := struct {
    44  		File *string `json:"file"`
    45  	}{}
    46  
    47  	if err := json.NewDecoder(r.Body).Decode(&reqJSON); err != nil {
    48  		errorResponse(w, http.StatusBadRequest, 13, "invalid argument", err.Error())
    49  		return
    50  	}
    51  
    52  	if reqJSON.File == nil {
    53  		errorResponse(w, http.StatusBadRequest, 13, "invalid argument", "file field is required in request")
    54  		return
    55  	}
    56  
    57  	buffer := &bytes.Buffer{}
    58  
    59  	if _, err := io.Copy(buffer, base64.NewDecoder(base64.StdEncoding, strings.NewReader(*reqJSON.File))); err != nil {
    60  		errorResponse(w, http.StatusBadRequest, 13, "invalid argument", err.Error())
    61  		return
    62  	}
    63  
    64  	dir, err := ioutil.TempDir(u.Root, "")
    65  	if err != nil {
    66  		errorResponse(w, http.StatusInternalServerError, 13, "unknown error", err.Error())
    67  		return
    68  	}
    69  
    70  	files, err := unzipFiles(dir, buffer.Bytes())
    71  	if err != nil {
    72  		f, err := uploadFile(dir, buffer.Bytes())
    73  		if err != nil {
    74  			errorResponse(w, http.StatusInternalServerError, 13, "unknown error", err.Error())
    75  			return
    76  		}
    77  		files = append(files, f)
    78  	}
    79  
    80  	respJSON := map[string]interface{}{
    81  		"status": 0,
    82  	}
    83  
    84  	if len(files) == 1 {
    85  		respJSON["value"] = files[0]
    86  	} else {
    87  		respJSON["value"] = files
    88  	}
    89  
    90  	w.Header().Set("Content-Type", "application/json; charset=utf-8")
    91  	httphelper.SetDefaultResponseHeaders(w.Header())
    92  	w.WriteHeader(http.StatusOK)
    93  	json.NewEncoder(w).Encode(respJSON)
    94  }
    95  
    96  func unzipFiles(dir string, contents []byte) ([]string, error) {
    97  	unzipped, err := zip.NewReader(bytes.NewReader(contents), int64(len(contents)))
    98  	if err != nil {
    99  		return nil, err
   100  	}
   101  
   102  	var files []string
   103  
   104  	for _, file := range unzipped.File {
   105  		path, err := unzipFile(dir, file)
   106  		if err != nil {
   107  			return nil, err
   108  		}
   109  		files = append(files, path)
   110  	}
   111  
   112  	return files, nil
   113  }
   114  
   115  func unzipFile(dir string, file *zip.File) (string, error) {
   116  	path := filepath.Join(dir, file.FileHeader.Name)
   117  	in, err := file.Open()
   118  	if err != nil {
   119  		return "", err
   120  	}
   121  	defer in.Close()
   122  
   123  	out, err := os.Create(path)
   124  	if err != nil {
   125  		return "", err
   126  	}
   127  	defer out.Close()
   128  
   129  	if _, err := io.Copy(out, in); err != nil {
   130  		return "", err
   131  	}
   132  
   133  	return path, nil
   134  }
   135  
   136  func uploadFile(dir string, contents []byte) (string, error) {
   137  	out, err := ioutil.TempFile(dir, "")
   138  	if err != nil {
   139  		return "", err
   140  	}
   141  	defer out.Close()
   142  
   143  	if _, err := out.Write(contents); err != nil {
   144  		return "", err
   145  	}
   146  
   147  	return out.Name(), nil
   148  }
   149  
   150  func errorResponse(w http.ResponseWriter, httpStatus, status int, err, message string) {
   151  	w.Header().Set("Content-Type", "application/json; charset=utf-8")
   152  	httphelper.SetDefaultResponseHeaders(w.Header())
   153  	w.WriteHeader(httpStatus)
   154  
   155  	respJSON := map[string]interface{}{
   156  		"status": status,
   157  		"value": map[string]interface{}{
   158  			"error":   err,
   159  			"message": message,
   160  		},
   161  	}
   162  
   163  	json.NewEncoder(w).Encode(respJSON)
   164  }