Aliyun OSS Nginx proxy module（阿里云OSS Nginx 签名代理模块）

1、此文章主要介绍内容

本文主要介绍如何利用Nginx lua 实现将阿里云OSS存储空间做到同本地磁盘一样使用。核心是利用Nginx lua 对OSS请求进行签名并利用内部跳转将所有访问本地Nginx的请求加上OSS 签名转发给OSS，实现本地Nginx无缝衔接阿里云OSS，存储空间无限扩展，存储成本无限下降，数据安全%99.99...... 。

2、本篇文章使用到的一些工具技术及如何学习和获取

1、lua

本文用到的都是一些基本的lua，基本上花半小时阅读下lua的语法就可以轻松理解本文内容

2、Nginx lua

主要是学习nginx lua 及环境部署，不过阅读本文还不需要亲自动手去学习及部署nginx lua 环境，读者可以从docker 官方镜像源pull openresty 镜像进行实验。本文已openresty/1.7.7.2 作为实验环境。

3、阿里云OSS

赶紧开通吧，用起来相当爽，一处存储全球无限制访问

https://www.aliyun.com/act/aliyun/ossdoc.html

4、参考博客

建议阅读我的另外一篇博客，对深入理解OSS 及互联网上提供的HTTP服务有更深刻的理解

https://yq.aliyun.com/articles/7511?spm=0.0.0.0.IWbHSR

3、利用Nginx lua 实现请求签名并转发至OSS

Lua 签名 code

注：此代码并非出自作者之手

oss_auth.lua

-- has been sorted in alphabetical order
local signed_subresources = {
'acl',
'append',
'bucketInfo',
'cname',
'commitTransition',
'comp',
'cors',
'delete',
'lifecycle',
'location',
'logging',
'mime',
'notification',
'objectInfo',
'objectMeta',
'partData',
'partInfo',
'partNumber',
'policy',
'position',
'referer',
'replication',
'replicationLocation',
'replicationProgress',
'requestPayment',
'response-cache-control',
'response-content-disposition',
'response-content-encoding',
'response-content-language',
'response-content-type',
'response-expires',
'restore',
'security-token',
'tagging',
'torrent',
'uploadId',
'uploads',
'versionId',
'versioning',
'versions',
'website'
}function string.startswith(s, start)
return string.sub(s, 1, string.len(start)) == start
endlocal function get_canon_sub_resource()
local args = ngx.req.get_uri_args()
-- lower keys
local keys = {}
for k, v in pairs(args) do
keys[k:lower()] = v
end
-- make resource string
local s = ''
local sep = '?'
for i, k in ipairs(signed_subresources) do
v = keys[k]
if v then
-- sub table
v = type(v) == 'table' and v[1] or v
s = s .. string.format("%s%s=%s", sep, k, v)
sep = '&'
end
end
return s
endlocal function get_canon_resource()
resource = ''
object = ngx.unescape_uri(ngx.var.uri)
sub = get_canon_sub_resource()
return string.format("/%s%s%s", ngx.var.oss_bucket, object, sub)
end local function get_canon_headers()
-- default: <lowerkey, value>
local headers = ngx.req.get_headers()
local keys = {}
for k, v in pairs(headers) do
if string.startswith(k, 'x-oss-') then
-- client must assemble the same header keys
if type(v) ~= 'string' then return nil end
table.insert(keys, k)
end
end
-- sorted in alphabetical order
table.sort(keys)
for i, key in ipairs(keys) do
keys[i] = key .. ':' .. headers[key] .. '\n'
end
return table.concat(keys)
endlocal function calc_sign(key, method, md5, type_, date, oss_headers, resource)
-- string_to_sign:
-- method + '\n' + content_md5 + '\n' + content_type + '\n'
-- + date + '\n' + canonicalized_oss_headers + canonicalized_resource
local sign_str = string.format('%s\n%s\n%s\n%s\n%s%s',
method, md5, type_,
date, oss_headers, resource)
ngx.log(ngx.ERR, "SignStr:", sign_str, "\n")
local sign_result = ngx.encode_base64(ngx.hmac_sha1(key, sign_str))
return sign_result, sign_str
end local function oss_auth()
-- ngx.log(ngx.INFO, 'auth')
--local method = ngx.var.request_method
local method = ngx.req.get_method()
local content_md5 = ngx.var.http_content_md5 or ''
local content_type = ngx.var.http_content_type or ''
-- get date
local date = ngx.var.http_x_oss_date or ngx.var.http_date or ''
if date == '' then
date = ngx.http_time(ngx.time())
-- ngx.log(ngx.INFO, 'Date:', date)
ngx.req.set_header('Date', date)
end
local resource = get_canon_resource()
local canon_headers = get_canon_headers()
local sign_result, sign_str = calc_sign(ngx.var.oss_auth_key, method, content_md5,
content_type, date, canon_headers, resource)
-- ngx.log(ngx.INFO, 'sign string:', sign_str)
-- ngx.log(ngx.INFO, 'sign string len:', string.len(sign_str))
local auth = string.format("OSS %s:%s", ngx.var.oss_auth_id, sign_result)
ngx.req.set_header('Authorization', auth)
ngx.exec("@oss")
end -- main
res = oss_auth()if res then
ngx.exit(res)
end


nginx.conf

server {
listen 8000; proxy_http_version 1.1;
proxy_buffering off;
proxy_request_buffering off; location / {
set $oss_bucket "your_oss_bucket";
set $oss_auth_id "your_access_id";
set $oss_auth_key "your_access_key";
rewrite_by_lua_file "/path/oss_auth.lua";
} # internal redirect
location @oss {
// endpoint eg: oss.aliyuncs.com
proxy_pass http://your_oss_bucket.endpoint;
}
}


、如何使用上述代码

首先oss_auth.lua 无需做任何改动

nginx.conf 中需要将

your_oss_bucket 替换为阿里云OSS 的bucket名

your_access_id替换未AccessKeyId

your_access_key 替换为 AccessKeySecret

例如：

error_log logs/error.log debug;
events {
worker_connections 1024;
}
http {
include mime.types;
lua_package_path "/usr/servers/lualib/?.lua;";
lua_package_cpath "/usr/servers/lualib/?.so;";
server {
listen 80；
location / {
set $oss_bucket "bucket-example";
set $oss_auth_id "za2127hbbdsdjhkhskel0ytocbzr";
set $oss_auth_key "gMOG3o+JHDSJHCNMcsaH+Q=";
rewrite_by_lua_file conf/lua/oss_auth.lua;
} location @oss {
proxy_pass http://bucket-example.oss-cn-qingdao.aliyuncs.com;
}
}
}