dongjiang1989 commented on code in PR #12772: URL: https://github.com/apache/apisix/pull/12772#discussion_r2634860483
########## apisix/discovery/zookeeper/init.lua: ########## @@ -0,0 +1,238 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- + +local core = require("apisix.core") +local utils = require("apisix.discovery.zookeeper.utils") +local lrucache = require("resty.lrucache") +local table = require("apisix.core.table") +local local_conf = require("apisix.core.config_local").local_conf() +local ngx = ngx +local ipairs = ipairs +local log = core.log + +local _M = { + version = 0.1, + priority = 1000, + name = "zookeeper", +} + +-- Global Configuration +local zookeeper_conf +-- Service Instance Cache（service_name -> {nodes, expire_time}） +local instance_cache = lrucache.new(1024) + +-- Timer Identifier +local fetch_timer + +-- The instance list of a single service from ZooKeeper +local function fetch_service_instances(conf, service_name) + -- 1. Init connect + local client, err = utils.new_zk_client(conf) + if not client then + return nil, err + end + + -- 2. Create path + local service_path = conf.root_path .. "/" .. service_name + local ok, err = utils.create_zk_path(client, service_path) + if not ok then + utils.close_zk_client(client) + return nil, err + end + + -- 3. All instance nodes under a service + local children, err = client:get_children(service_path) + if not children then + utils.close_zk_client(client) + if err == "not exists" then + log.warn("service path not exists: ", service_path) + return {} + end + log.error("get zk children failed: ", err) + return nil, err + end + + -- 4. Parse the data of each instance node one by one + local instances = {} + for _, child in ipairs(children) do + local instance_path = service_path .. "/" .. child + local data, stat, err = client:get_data(instance_path) + do + if not data then + log.error("get instance data failed: ", instance_path, " stat:", stat, " err: ", err) + break + end + + -- Parse instance data + local instance = utils.parse_instance_data(data) + if instance then + table.insert(instances, instance) + end + end + end + + -- 5. Close connects + utils.close_zk_client(client) + + log.debug("fetch service instances: ", service_name, " count: ", #instances) + return instances +end + +-- Scheduled fetch of all service instances (full cache update)） +local function fetch_all_services() + if not zookeeper_conf then + log.warn("zookeeper discovery config not loaded") + return + end + + -- 1. Init Zookeeper client + local client, err = utils.new_zk_client(zookeeper_conf) + if not client then + log.error("init zk client failed: ", err) + return + end + + -- 2. Check instance root path exist + local ex, err = client:exists(zookeeper_conf.root_path) + if ex == false then + local created_parent, cerr = client:create(zookeeper_conf.root_path, "", "persistent", false) + if not created_parent then + utils.close_zk_client(client) + log.error("failed to create parent: ", cerr) + end + elseif err then + utils.close_zk_client(client) + log.error("exist zk root failed: ", err) + return + end + + -- 3. All instance nodes under a service + local services, err = client:get_children(zookeeper_conf.root_path) + if not services then + utils.close_zk_client(client) + log.error("get zk root children failed: ", err) + return + end + + -- 4. Fetch the instances of each service and update the cache + local now = ngx.time() + for _, service in ipairs(services) do + local instances, err = fetch_service_instances(zookeeper_conf, service) + if instances then + instance_cache:set(service, { + nodes = instances, + }, now + zookeeper_conf.cache_ttl) + else + log.error("fetch service instances failed: ", service, " err: ", err) + end + end + + -- 5. Close connects + utils.close_zk_client(client) +end + +function _M.nodes(service_name) + if not service_name or service_name == "" then + log.error("service name is empty") + return nil + end + + -- 1. Check instance_cache initialized + if not instance_cache then + log.error("instance_cache not initialized") + return nil + end + + -- 2. Get from cache + local cache, _, _ = instance_cache:get(service_name) + local now = ngx.time() + + -- 3. If the cache is missed or expired, actively pull (the data)） + if not cache or cache.expire_time < now then + log.debug("cache miss or expired, fetch from zk: ", service_name) + local instances, err = fetch_service_instances(zookeeper_conf, service_name) + if not instances then + log.error("fetch instances failed: ", service_name, " err: ", err) + -- Fallback: Return the old cache (if available)） + if cache then + return cache.nodes + end + return nil + end + + -- Update the cache + cache = { + nodes = instances, + } + + instance_cache:set(service_name, cache, now + zookeeper_conf.cache_ttl) + end + + return cache.nodes +end + +function _M.init_worker() + -- Load configuration + zookeeper_conf = local_conf.discovery and local_conf.discovery.zookeeper or {} + + -- The default values + zookeeper_conf.connect_string = zookeeper_conf.connect_string or "127.0.0.1:2181" + zookeeper_conf.fetch_interval = zookeeper_conf.fetch_interval or 10 + zookeeper_conf.session_timeout = zookeeper_conf.session_timeout or 30000 + zookeeper_conf.connect_timeout = zookeeper_conf.connect_timeout or 5000 + zookeeper_conf.cache_ttl = zookeeper_conf.cache_ttl or 30 + zookeeper_conf.root_path = zookeeper_conf.root_path or "/apisix/discovery/zk" + zookeeper_conf.auth = zookeeper_conf.auth or {type = "digest", creds = "",} Review Comment: Thanks @Baoyuantop Fixed -- This is an automated message from the Apache Git Service. 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