Baoyuantop commented on code in PR #12772: URL: https://github.com/apache/apisix/pull/12772#discussion_r2583496791
########## apisix/discovery/zookeeper/init.lua: ########## @@ -0,0 +1,209 @@ +-- +-- 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 schema = require("apisix.discovery.zookeeper.schema") +local table = require("apisix.core.table") +local ngx = ngx +local ipairs = ipairs +local log = core.log + +local _M = { + version = 0.1, + priority = 1000, + name = "zookeeper", + schema = schema.schema, +} + +-- Global Configuration +local local_conf Review Comment: It is recommended that the main process request the service instance from ZooKeeper and synchronize it to the worker processes via the shared dict. ########## apisix/discovery/zookeeper/init.lua: ########## @@ -0,0 +1,209 @@ +-- +-- 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 schema = require("apisix.discovery.zookeeper.schema") +local table = require("apisix.core.table") +local ngx = ngx +local ipairs = ipairs +local log = core.log + +local _M = { + version = 0.1, + priority = 1000, + name = "zookeeper", + schema = schema.schema, +} + +-- Global Configuration +local local_conf +-- Service Instance Cache（service_name -> {nodes, expire_time}） +local instance_cache = core.lrucache.new({ + ttl = 3600, + count = 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. TODO: 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(instance_path) + if not data then + log.error("get instance data failed: ", instance_path, " stat:", stat, " err: ", err) + goto continue + end + + -- Parse instance data + local instance = utils.parse_instance_data(data) + if instance then + table.insert(instances, instance) + end + + ::continue:: + 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 local_conf then + log.warn("zookeeper discovery config not loaded") + return + end + + -- 1. Init Zookeeper client + local client, err = utils.new_zk_client(local_conf) + if not client then + log.error("init zk client failed: ", err) + return + end + + -- 2. All instance nodes under a service + local services, err = client:get_children(local_conf.root_path) + if not services then + utils.close_zk_client(client) + log.error("get zk root children failed: ", err) + return + end + + -- 3. 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(local_conf, service) + if instances then + instance_cache:set(service, nil, { + nodes = instances, + expire_time = now + local_conf.cache_ttl + }) + else + log.error("fetch service instances failed: ", service, " err: ", err) + end + end + + -- 4. 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. Get from cache + local cache = instance_cache:get(service_name) + local now = ngx.time() + + -- 2. 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(local_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, + expire_time = now + local_conf.cache_ttl + } + instance_cache:set(service_name, nil, cache) + end + + return cache.nodes +end + +function _M.check_schema(conf) + return schema.check(conf) +end + +function _M.init_worker() + -- Load configuration + local core_config = core.config.local_conf + local_conf = core_config.discovery and core_config.discovery.zookeeper or {} + local ok, err = schema.check(local_conf) + if not ok then + log.error("invalid zookeeper discovery config: ", err) + return + end + + -- The default values + local_conf.connect_string = local_conf.connect_string or "127.0.0.1:2181" + local_conf.fetch_interval = local_conf.fetch_interval or 10 + local_conf.cache_ttl = local_conf.cache_ttl or 30 + + -- Start the timer + if not fetch_timer then + fetch_timer = ngx.timer.every(local_conf.fetch_interval, fetch_all_services) + log.info("zk discovery fetch timer started, interval: ", local_conf.fetch_interval, "s") + end + + -- Manually execute a full pull immediately + ngx.timer.at(0, fetch_all_services) +end + +function _M.destroy() + if fetch_timer then + fetch_timer = nil + end + instance_cache:flush_all() + log.info("zookeeper discovery destroyed") +end + Review Comment: A dump method is also needed to retrieve all services in the current service discovery instance. You can explore other service discovery modules for more information. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
