nginx_lua case analysis: dynamic routing implementation

from ceryx.db import RedisRouter resource_fields = { 'source': fields.String, 'target': fields.String, } parser = reqparse.RequestParser() parser.add_argument( 'source', type=str, required=True, help='Source is required' ) parser.add_argument( 'target', type=str, required=True, help='Target is required' ) router = RedisRouter.from_config() def lookup_or_abort(source): """ Returns the target for the given source, or aborts raising a 404 """ try: return {'source': source, 'target': router.lookup(source)} except RedisRouter.LookupNotFound: abort( 404, message='Route with source {} doesn\'t exist'.format(source) ) class Route(Resource): """ Resource describing a single Route. Supports GET, DELETE and PUT. The format is the following: ``` { "source": "[source]", "target": "[target]" } ``` """ @marshal_with(resource_fields) def get(self, source): """ Fetches the route with the given source """ route = lookup_or_abort(source) return route @marshal_with(resource_fields) def delete(self, source): """ Deletes the route with the given source """ route = lookup_or_abort(source) router.delete(source) return route, 204 @marshal_with(resource_fields) def put(self, source): """ Creates or updates the route with the given source, pointing to the given target """ args = parser.parse_args() router.insert(args['source'], args['target']) return args, 201

upstream fallback { server www.something.com; } server { listen 80; default_type text/html; location / { set $container_url "fallback"; resolver 8.8.8.8; # Lua files access_by_lua_file lualib/router.lua;//切入点 # Proxy configuration proxy_set_header Host $http_host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-Proto $scheme; proxy_redirect ~^(http://[^:]+):\d+(/.+)$ $2; proxy_redirect / /; # Upgrade headers proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_pass http://$container_url$request_uri; } ... }

local container_url = ngx.var.container_url//拿到配置文件中的container_url local host = ngx.var.host //拿到请求的时候的host，比如我们请求http://www.xxx.com/a.html 那这里的host就是www.xxx.com -- Check if key exists in local cache local cache = ngx.shared.ceryx local res, flags = cache:get(host) //直接在nginx cache中拿host对应的路由映射，如果存在则直接返回结果 if res then ngx.var.container_url = res return end local redis = require "resty.redis" // redis的连接代码 每次都会连接redis， local red = redis:new() //这个操作比较相对比较耗时 所以接下来的操作才会在本地cache中存对应的关系 red:set_timeout(100) -- 100 ms local redis_host = os.getenv("CERYX_REDIS_HOST") if not redis_host then redis_host = "127.0.0.1" end local redis_port = os.getenv("CERYX_REDIS_PORT") if not redis_port then redis_port = 6379 end local res, err = red:connect(redis_host, redis_port) -- Return if could not connect to Redis if not res then return end -- Construct Redis key local prefix = os.getenv("CERYX_REDIS_PREFIX") if not prefix then prefix = "ceryx" end local key = prefix .. ":routes:" .. host -- Try to get target for host res, err = red:get(key) if not res or res == ngx.null then -- Construct Redis key for $wildcard key = prefix .. ":routes:$wildcard" res, err = red:get(key) if not res or res == ngx.null then return end ngx.var.container_url = res return end -- Save found key to local cache for 5 seconds cache:set(host, res, 5) // 在redis取出的映射关系存到redis的cache中避免下次继续连redis操作 ngx.var.container_url = res