| -- |
| -- 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 config_local = require("apisix.core.config_local") |
| local is_http = ngx.config.subsystem == "http" |
| local ipairs = ipairs |
| local error = error |
| |
| |
| local dns_client |
| local _M = {} |
| |
| |
| function _M.nodes(service_name) |
| local host, port = core.utils.parse_addr(service_name) |
| core.log.info("discovery dns with host ", host, ", port ", port) |
| |
| local records, err = dns_client:resolve(host, core.dns_client.RETURN_ALL) |
| if not records then |
| return nil, err |
| end |
| |
| local nodes = core.table.new(#records, 0) |
| local index = 1 |
| for _, r in ipairs(records) do |
| if r.address then |
| local node_port = port |
| if not node_port and r.port ~= 0 then |
| -- if the port is zero, fallback to use the default |
| node_port = r.port |
| end |
| |
| -- ignore zero port when subsystem is stream |
| if node_port or is_http then |
| nodes[index] = {host = r.address, weight = r.weight or 1, port = node_port} |
| if r.priority then |
| -- for SRV record, nodes with lower priority are chosen first |
| nodes[index].priority = -r.priority |
| end |
| index = index + 1 |
| end |
| end |
| end |
| |
| return nodes |
| end |
| |
| |
| function _M.init_worker() |
| local local_conf = config_local.local_conf() |
| local servers = local_conf.discovery.dns.servers |
| local resolv_conf = local_conf.discovery.dns.resolv_conf |
| local default_order = {"last", "SRV", "A", "AAAA", "CNAME"} |
| local order = core.table.try_read_attr(local_conf, "discovery", "dns", "order") |
| order = order or default_order |
| |
| local opts = { |
| hosts = {}, |
| resolvConf = resolv_conf, |
| nameservers = servers, |
| order = order, |
| } |
| |
| local client, err = core.dns_client.new(opts) |
| if not client then |
| error("failed to init the dns client: ", err) |
| return |
| end |
| |
| dns_client = client |
| end |
| |
| |
| return _M |