OpenResty文件上传

OpenResty文件上传

介绍

本文对OpenResty实现文件上传进行简单介绍,主要用到resty.upload中的API,下面我们来看下

lua-resty-upload中的上传示例

先看一个lua-resty-upload中的上传示例:

    lua_package_path "/path/to/lua-resty-upload/lib/?.lua;;";

    server {
        location /test {
            content_by_lua '
                local upload = require "resty.upload"
                local cjson = require "cjson"

                local chunk_size = 5 -- should be set to 4096 or 8192
                                     -- for real-world settings

                local form, err = upload:new(chunk_size)
                if not form then
                    ngx.log(ngx.ERR, "failed to new upload: ", err)
                    ngx.exit(500)
                end

                form:set_timeout(1000) -- 1 sec

                while true do
                    local typ, res, err = form:read()
                    if not typ then
                        ngx.say("failed to read: ", err)
                        return
                    end

                    ngx.say("read: ", cjson.encode({typ, res}))

                    if typ == "eof" then
                        break
                    end
                end

                local typ, res, err = form:read()
                ngx.say("read: ", cjson.encode({typ, res}))
            ';
        }
    }
复制代码

lua-resty-upload库支持 multipart/form-data MIME 类型。这个库的API通过循环调用form:read()返回token数据,token数据为数组,以header, body, part end,eof为开头,直到返回nil的token类型。如下所示:

read: ["header",["Content-Disposition","form-data; name=\"file1\"; filename=\"a.txt\"","Content-Disposition: form-data; name=\"file1\"; filename=\"a.txt\""]]
read: ["header",["Content-Type","text\/plain","Content-Type: text\/plain"]]
read: ["body","Hello"]
read: ["body",", wor"]
read: ["body","ld"]
read: ["part_end"]
read: ["header",["Content-Disposition","form-data; name=\"test\"","Content-Disposition: form-data; name=\"test\""]]
read: ["body","value"]
read: ["body","\r\n"]
read: ["part_end"]
read: ["eof"]
read: ["eof"]
复制代码

这就是流式阅读的工作原理。 即使是千兆字节的文件数据输入,只要用户自己不积累输入数据块,lua 域中使用的内存也可以很小且恒定。

此Lua 库利用了 ngx_lua 的 cosocket API,它确保了 100% 的非阻塞行为。

upload的简单封装

下面再来看一个使用的简单封装:

local _M = {
    _VERSION = '0.01'
}

local upload = require "resty.upload"
local chunk_size = 4096
local cjson = require 'cjson.safe'
local os_exec = os.execute
local os_date = os.date
local md5 = ngx.md5
local io_open = io.open
local tonumber = tonumber
local gsub = string.gsub
local ngx_var = ngx.var
local ngx_req = ngx.req
local os_time = os.time
local json_encode = cjson.encode



local function get_ext(res)
    local kvfile = string.split(res, "=")
    local filename = string.sub(kvfile[2], 2, -2)
    if filename then
        return filename:match(".+%.(%w+)$")
    end
    return ''
end

local function file_exists(path)
    local file = io.open(path, "rb")
    if file then file:close() end
    return file ~= nil
end

local function json_return(code, message, data)
    ngx.say(json_encode({code = code, msg = message, data = data}))
end

local function in_array(b,list)
    if not list then
        return false
    end
    if list then
        for k, v in pairs(list) do
            if v == b then
                return true
            end
        end
        return false
    end
end

-- 字符串 split 分割
string.split = function(s, p)
    local rt= {}
    gsub(s, '[^'..p..']+', function(w) table.insert(rt, w) end )
    return rt
end

-- 支持字符串前后 trim
string.trim = function(s)
    return (s:gsub("^%s*(.-)%s*$", "%1"))
end

local function uploadfile()
    local file
    local file_name
    local form = upload:new(chunk_size)
    local conf = {max_size = 1000000, allow_exts = {'jpg', 'png', 'gif', 'jpeg'} }
    local root_path = ngx_var.document_root
    local file_info = {extension = '', filesize = 0, url = '', mime = '' }
    local content_len = ngx_req.get_headers()['Content-length']
    local body_size = content_len and tonumber(content_len) or 0
    if not form then
        return nil, '没有上传的文件'
    end
    if body_size > 0 and body_size > conf.max_size then
        return nil, '文件过大'
    end
    file_info.filesize = body_size
    while true do
        local typ, res, err = form:read()
        if typ == "header" then
            if res[1] == "Content-Type" then
                file_info.mime = res[2]
            elseif res[1] == "Content-Disposition" then
                -- 如果是文件参数:Content-Disposition: form-data; name="data"; filename="1.jpeg"
                local kvlist = string.split(res[2], ';')
                for _, kv in ipairs(kvlist) do
                    local seg = string.trim(kv)
                    -- 带filename标识则为文件参数名
                    if seg:find("filename") then
                        local file_id = md5('upload'..os_time())
                        local extension = get_ext(seg)
                        file_info.extension = extension

                        if not extension then
                            return nil,  '未获取文件后缀'
                        end

                        if not in_array(extension, conf.allow_exts) then
                            return nil,  '不支持该文件格式'
                        end

                        local dir = root_path..'/uploads/images/'..os_date('%Y')..'/'..os_date('%m')..'/'..os_date('%d')..'/'
                        if file_exists(dir) ~= true then
                            local status = os_exec('mkdir -p '..dir)
                            if status ~= true then
                                return nil, '创建目录失败'
                            end
                        end
                        file_name = dir..file_id.."."..extension
                        if file_name then
                            file = io_open(file_name, "w+")
                            if not file then
                                return nil, '打开文件失败'
                            end
                        end
                    end
                end

            end
        elseif typ == "body" then
            -- 读取body内容
            if file then
                file:write(res)
            end
        elseif typ == "part_end" then
            -- 写结束,关闭文件
            if file then
                file:close()
                file = nil
            end
        elseif typ == "eof" then
            -- 读取结束返回
            file_name = gsub(file_name, root_path, '')
            file_info.url = file_name
            return file_info
        else

        end
    end
end

local file_info, err = uploadfile()
if file_info then
    json_return(200, '上传成功', {imgurl = file_info.url})
else
    json_return(5003, err)
end
复制代码

上面封装是使用openresty-practices进行相应修改后的上传代码.文件名称:md5('upload'..os_time()),如果想使用封装的uuid生成文件名称,可以使用lua-resty-uuid库,复制到OpenResty安装目录lualib.resty下代码中引用require 'resty.uuid'即可使用。

下面我们来对此进行测试,我们先配置nginx.conf:

worker_processes 1;

events {
  worker_connections 1024;
}

http {
  lua_package_path "$prefix/lua/?.lua;$prefix/libs/?.lua;;";
  server {
    server_name localhost;
    listen 8080;
    charset utf-8;
    set $LESSON_ROOT lua/;
    error_log  logs/error.log;
    access_log logs/access.log;
    location /upload{
      default_type text/html;
      content_by_lua_file $LESSON_ROOT/upload.lua;
    }
  }

}
复制代码

测试前我们已经在Mac上安装了OpenResty,具体安装步骤可以查看OpenResty在Mac上的安装.接下来我们就来测试下上面的上传代码.

我们来看下当前的目录结构:

wukongdeMacBook-Pro:upload wukong$ tree

.

|-- conf

|   `-- nginx.conf

|-- logs

|   |-- access.log

|   `-- error.log

|-- lua

|   `-- upload.lua
复制代码

我们进到该目录执行如下命令启动上传应用:

wukongdeMacBook-Pro:upload wukong$ openresty -p $PWD/   -c conf/nginx.conf
复制代码

接下来我们通过IDEA的HTTP Request来设置图片上传的post请求:

### Send a form with the text and file fields
POST http://127.0.0.1:8080/upload
Content-Type: multipart/form-data; boundary=WebAppBoundary

--WebAppBoundary
Content-Disposition: form-data; name="element-name"
Content-Type: text/plain

123
--WebAppBoundary
Content-Disposition: form-data; name="files"; filename="1.jpeg"

< /Users/wukong/Desktop/1.jpeg
--WebAppBoundary--
复制代码

图片路径为/Users/wukong/Desktop/1.jpeg,然后我们执行上面的请求,会看到如下返回:

{"msg":"上传成功","data":{"imgurl":"\/Users\/wukong\/Desktop\/tool\/openresty-test\/upload\/html\/uploads\/images\/2022\/03\/04\/87671af7f050839a463fafff52d5156e.jpeg"},"code":200}
复制代码

上传成功。

image.png

分类:
后端
标签: