nginx-upload-module模块实现文件断点续传

导读	每当我们想简单的实现文件上传功能，而又不使用其他的语言（比如PHP、Java），或者想实现文件的断点续传。这个时候Nginx的一个模块nginx-upload-module就能满足我们的需求。

模块安装

下载模块：

cd /tmp
wget https://codeload.github.com/vkholodkov/nginx-upload-module/zip/2.2
unzip 2.2

安装模块：

.configure --add-module=/tmp/nginx-upload-module-2.2/

multipart/form-data表单上传示例

nginx.conf配置：

server {
  [...]
         location /upload {
                upload_pass @uploadHandler;
                upload_store /usr/local/nginx/upload_temp 1;
                upload_set_form_field $upload_field_name.path "$upload_tmp_path";
        }

         location @uploadHandler {
                proxy_pass http://backend-host;
        }
    [...]
    }

这里在server里定义了upload location，这个location是上传的接口，还有@uploadHandler location，是当文件上传完成后，nginx模块会对这个location发送一些必要的信息，如文件上传的路径，这里涉及了几个指令：

upload_pass @uploadHandler：上传完成后会发送必要的数据到@uploadHandler;
upload_store /usr/local/nginx/upload_temp 1: 文件上传的临时目录;
upload_set_form_field $upload_field_name.path “$upload_tmp_path”: 设置文件上传完成后，把文件临时路径发送给upload_pass指定的location。

断点续传示例

nginx.conf配置

server {
[...]
        location /resumable_upload {
               upload_resumable on;
               upload_state_store /usr/local/nginx/upload_temp ;
               upload_pass @drivers_upload_handler;
               upload_store /usr/local/nginx/upload_temp;
               upload_set_form_field $upload_field_name.path "$upload_tmp_path";
            }

         location @resumable_upload_handler {
               proxy_pass http://localhost:8002;
        }
    [...]
    }

与上一步multipart/form-data表单上传示例配置不同的地方有：
upload_resumable on: 开启断点续传功能;
upload_state_store /usr/local/nginx/upload_temp: 设置断点续传状态文件存储的目录。

上传文件第一个片段

POST /upload HTTP/1.1
Host: example.com
Content-Length: 51201
Content-Type: application/octet-stream
Content-Disposition: attachment; filename="big.TXT"
X-Content-Range: bytes 0-51200/511920
Session-ID: 1111215056

<0-51200的字节文件数据>

上传文件第一个片段服务器响应

HTTP/1.1 201 Created
Date: Thu, 02 Sep 2010 12:54:40 GMT
Content-Length: 14
Connection: close
Range: 0-51200/511920

0-51200/511920

上传文件最后一个片段

POST /upload HTTP/1.1
Host: example.com
Content-Length: 51111
Content-Type: application/octet-stream
Content-Disposition: attachment; filename="big.TXT"
X-Content-Range: bytes 460809-511919/511920
Session-ID: 1111215056

<460809-511919字节文件数据>

上传文件最后一个片段服务器响应

HTTP/1.1 200 OK
Date: Thu, 02 Sep 2010 12:54:43 GMT
Content-Type: text/html
Connection: close
Content-Length: 2270

< 响应的内容>

请求头说明

  请求头 	                      说明
Content-Disposition  attachment, filename=“上传的文件名”
Content-Type 	     待上传文件的mime type,如application/octet-stream(注:不能为multipart/form-data)
X-Content-Range      待上传文件字节范围,如第一片段bytes 0-51200/511920,最后一个片段bytes 460809-511919/511920(注:文件第一个字节标号为0,最后一个字节标号为n-1,其中n为文件字节大小)
X-Session-ID 	     上传文件的标识,由客户端随机指定.因为是断点续传,客户端必须确保同一个文件的所有片段上传标识一致
Content-Length 	     上传片段的大小

Python上传demo

#!/usr/bin/python
# -*- coding: utf-8 -*- 

import os.path
import requests
import hashlib

# 待上传文件路径
FILE_UPLOAD = "/tmp/testfile"
# 上传接口地址
UPLOAD_URL = "http://host/drivers_upload"
# 单个片段上传的字节数
SEGMENT_SIZE = 1048576

def upload(fp, file_pos, size, file_size):
        session_id = get_session_id()
        fp.seek(file_pos)
        payload = fp.read(size)
        content_range = "bytes {file_pos}-{pos_end}/{file_size}".format(file_pos=file_pos,
                        pos_end=file_pos+size-1,file_size=file_size)
        headers = {'Content-Disposition': 'attachment; filename="big.TXT"','Content-Type': 'application/octet-stream',
                    'X-Content-Range':content_range,'Session-ID': session_id,'Content-Length': size}
        res = requests.post(UPLOAD_URL, data=payload, headers=headers)
        print(res.text)

# 根据文件名hash获得session id
def get_session_id():
  m = hashlib.md5()
  file_name = os.path.basename(FILE_UPLOAD)
  m.update(file_name)
  return m.hexdigest()

def main():
  file_pos = 0
  file_size = os.path.getsize(FILE_UPLOAD)
  fp = open(FILE_UPLOAD,"r")

  while True:
   if file_pos + SEGMENT_SIZE >= file_size:
       upload(fp, file_pos, file_size - file_pos, file_size)
       fp.close()
       break
   else:
     upload(fp, file_pos, SEGMENT_SIZE, file_size)
     file_pos = file_pos + SEGMENT_SIZE

if __name__ == "__main__":
        main()