tokers commented on a change in pull request #2926: URL: https://github.com/apache/apisix/pull/2926#discussion_r534007761
########## File path: apisix/plugins/server-info.lua ########## @@ -0,0 +1,274 @@ +-- +-- 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 require = require +local core = require("apisix.core") + +local ngx_time = ngx.time +local ngx_timer_at = ngx.timer.at +local ngx_worker_id = ngx.worker.id +local type = type + +local plugin_name = "server-info" +local boot_time = os.time() +local current_timer +local schema = { + type = "object", + additionalProperties = false, +} +local attr_schema = { + type = "object", + properties = { + report_interval = { + type = "integer", + description = "server info reporting interval (unit: second)", + default = 60, + minimum = 5, + } + } +} + +local internal_status = ngx.shared.internal_status +if not internal_status then + error("lua_shared_dict \"internal_status\" not configured") +end + + +local _M = { + version = 0.1, + priority = 990, + name = plugin_name, + schema = schema, +} + + +local function uninitialized_server_info() + return { + etcd_version = "unknown", + hostname = core.utils.gethostname(), + id = core.id.get(), + version = core.version.VERSION, + up_time = ngx_time() - boot_time, + last_report_time = -1, + } +end + + +-- server information will be saved into shared memory only if the key +-- "server_info" not exist if excl is true. +local function save(data, excl) + local handler = excl and internal_status.add or internal_status.set + + local ok, err = handler(internal_status, "server_info", data) + if not ok then + if excl and err == "exists" then + return true + end + + return nil, err + end + + return true +end + + +local function encode_and_save(server_info, excl) + local data, err = core.json.encode(server_info) + if not data then + return nil, err + end + + return save(data, excl) +end + + +local function get() + local data, err = internal_status:get("server_info") + if err ~= nil then + return nil, err + end + + if not data then + return uninitialized_server_info() + end + + local server_info, err = core.json.decode(data) + if not server_info then + return nil, err + end + + server_info.up_time = ngx_time() - boot_time + return server_info +end + + +local function get_server_info() + local server_info, err = get() + if not server_info then + core.log.error("failed to get server_info: ", err) + return 500, err + end + + return 200, core.json.encode(server_info) +end + + +local function report() + local server_info, err = get() + if not server_info then + core.log.error("failed to get server_info: ", err) + return + end + + if server_info.etcd_version == "unknown" then + local res, err = core.etcd.server_version() + if not res then + core.log.error("failed to fetch etcd version: ", err) + return + + elseif type(res.body) ~= "table" then + core.log.error("failed to fetch etcd version: bad version info") + return + + else + server_info.etcd_version = res.body.etcdcluster + end + end + + server_info.last_report_time = ngx_time() + + local data, err = core.json.encode(server_info) + if not data then + core.log.error("failed to encode server_info: ", err) + return + end + + local key = "/data_plane/server_info/" .. server_info.id + local ok, err = core.etcd.set(key, data, 180) + if not ok then + core.log.error("failed to report server info to etcd: ", err) + return + end + + local ok, err = save(data, false) + if not ok then + core.log.error("failed to encode and save server info: ", err) + return + end +end + + +function _M.check_schema(conf) + local ok, err = core.schema.check(schema, conf) + if not ok then + return false, err + end + + return true +end + + +function _M.init() + if ngx_worker_id() ~= 0 then + -- only let the No.0 worker to launch timer for server info reporting. + return + end + + local ok, err = encode_and_save(uninitialized_server_info(), true) + if not ok then + core.log.error("failed to encode and save server info: ", err) + end + + if core.config ~= require("apisix.core.config_etcd") then + -- we don't need to report server info if etcd is not in use. + return + end + + local local_conf = core.config.local_conf() + local attr = core.table.try_read_attr(local_conf, "plugin_attr", + plugin_name) + local ok, err = core.schema.check(attr_schema, attr) + if not ok then + core.log.error("failed to check plugin_attr: ", err) + return + end + + local report_interval = attr.report_interval + + -- we don't use core.timer and the apisix.timers here for: + -- 1. core.timer is not cancalable, timers will be leaked if plugin + -- reloading happens. + -- 2. the background timer in apisix.timers fires per 500 milliseconds, if + -- report_interval is not multiple of 0.5, the real report interval will be + -- inaccurate over time. + local fn + fn = function(premature, timer) + if premature or timer.cancelled then + return + end + + report() + + if not timer.cancelled then + local ok, err = ngx_timer_at(report_interval, fn, timer) + if not ok then + core.log.error("failed to create timer to report server info: ", err) + end + + else + core.log.warn("server info report timer is cancelled") + end + end + + current_timer = { + cancelled = false + } + + local ok, err = ngx_timer_at(0, fn, current_timer) + if ok then + core.log.info("timer created to report server info, interval: ", + report_interval) + else + core.log.error("failed to create timer to report server info: ", err) + end +end + + +function _M.destory() + if ngx_worker_id() ~= 0 then + -- timer exists only in the No.0 worker. + return + end + + if current_timer then + current_timer.cancelled = true + current_timer = nil + end +end + + +function _M.api() + return { + { + methods = {"GET"}, + uri = "/apisix/server_info", + handler = get_server_info, Review comment: That is to say we haven't a way to expose these data in data plane, at least for now. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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