revert: "change: delete the server-info plugin"

apisix/cli/config.lua

@@ -236,6 +236,7 @@ local _M = {
     "limit-count",
     "limit-req",
     "gzip",
+    "server-info",
     "traffic-split",
     "redirect",
     "response-rewrite",
@@ -321,6 +322,9 @@ local _M = {
         port = 9091
       }
     },
+    ["server-info"] = {
+      report_ttl = 60
+    },
     ["dubbo-proxy"] = {
       upstream_multiplex_count = 32
     },

apisix/plugins/server-info.lua

@@ -0,0 +1,315 @@
+--
+-- 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 timers = require("apisix.timers")
+local plugin = require("apisix.plugin")
+
+local ngx_time = ngx.time
+local ngx_timer_at = ngx.timer.at
+local ngx_worker_id = ngx.worker.id
+local type = type
+
+local load_time = os.time()
+local plugin_name = "server-info"
+local default_report_ttl = 60
+local lease_id
+
+local schema = {
+    type = "object",
+}
+local attr_schema = {
+    type = "object",
+    properties = {
+        report_ttl = {
+            type = "integer",
+            description = "live time for server info in etcd",
+            default = default_report_ttl,
+            minimum = 3,
+            maximum = 86400,
+        }
+    }
+}
+
+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,
+    scope = "global",
+}
+
+
+local function get_boot_time()
+    local time, err = internal_status:get("server_info:boot_time")
+    if err ~= nil then
+        core.log.error("failed to get boot_time from shdict: ", err)
+        return load_time
+    end
+
+    if time ~= nil then
+        return time
+    end
+
+    local _, err = internal_status:set("server_info:boot_time", load_time)
+    if err ~= nil then
+        core.log.error("failed to save boot_time to shdict: ", err)
+    end
+
+    return load_time
+end
+
+
+local function uninitialized_server_info()
+    local boot_time = get_boot_time()
+    return {
+        etcd_version     = "unknown",
+        hostname         = core.utils.gethostname(),
+        id               = core.id.get(),
+        version          = core.version.VERSION,
+        boot_time        = boot_time,
+    }
+end
+
+
+local function get()
+    local data, err = internal_status:get("server_info")
+    if err ~= nil then
+        core.log.error("get error: ", err)
+        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
+        core.log.error("failed to decode server_info: ", err)
+        return nil, err
+    end
+
+    return server_info
+end
+
+
+local function get_server_info()
+    local info, err = get()
+    if not info then
+        core.log.error("failed to get server_info: ", err)
+        return 500
+    end
+
+    return 200, info
+end
+
+
+local function set(key, value, ttl)
+    local res_new, err = core.etcd.set(key, value, ttl)
+    if not res_new then
+        core.log.error("failed to set server_info: ", err)
+        return nil, err
+    end
+
+    if not res_new.body.lease_id then
+        core.log.error("failed to get lease_id: ", err)
+        return nil, err
+    end
+
+    lease_id = res_new.body.lease_id
+
+    -- set or update lease_id
+    local ok, err = internal_status:set("lease_id", lease_id)
+    if not ok then
+        core.log.error("failed to set lease_id to shdict: ", err)
+        return nil, err
+    end
+
+    return true
+end
+
+
+local function report(premature, report_ttl)
+    if premature then
+        return
+    end
+
+    -- get apisix node info
+    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
+            if res.body.etcdcluster == "" then
+                server_info.etcd_version = res.body.etcdserver
+            else
+                server_info.etcd_version = res.body.etcdcluster
+            end
+        end
+    end
+
+    -- get inside etcd data, if not exist, create it
+    local key = "/data_plane/server_info/" .. server_info.id
+    local res, err = core.etcd.get(key)
+    if not res or (res.status ~= 200 and res.status ~= 404) then
+        core.log.error("failed to get server_info from etcd: ", err)
+        return
+    end
+
+    if not res.body.node then
+        local ok, err = set(key, server_info, report_ttl)
+        if not ok then
+            core.log.error("failed to set server_info to etcd: ", err)
+            return
+        end
+
+        return
+    end
+
+    local ok = core.table.deep_eq(server_info, res.body.node.value)
+    -- not equal, update it
+    if not ok then
+        local ok, err = set(key, server_info, report_ttl)
+        if not ok then
+            core.log.error("failed to set server_info to etcd: ", err)
+            return
+        end
+
+        return
+    end
+
+    -- get lease_id from ngx dict
+    lease_id, err = internal_status:get("lease_id")
+    if not lease_id then
+        core.log.error("failed to get lease_id from shdict: ", err)
+        return
+    end
+
+    -- call keepalive
+    local res, err = core.etcd.keepalive(lease_id)
+    if not res then
+        core.log.error("send heartbeat failed: ", err)
+        return
+    end
+
+    local data, err = core.json.encode(server_info)
+    if not data then
+        core.log.error("failed to encode server_info: ", err)
+        return
+    end
+
+    local ok, err = internal_status:set("server_info", data)
+    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.control_api()
+    return {
+        {
+            methods = {"GET"},
+            uris ={"/v1/server_info"},
+            handler = get_server_info,
+        }
+    }
+end
+
+
+function _M.init()
+    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 deployment_role = core.table.try_read_attr(
+                       local_conf, "deployment", "role")
+    if deployment_role == "data_plane" then
+        -- data_plane should not write to etcd
+        return
+    end
+
+    local attr = plugin.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_ttl = attr and attr.report_ttl or default_report_ttl
+    local start_at = ngx_time()
+
+    local fn = function()
+        local now = ngx_time()
+        -- If ttl remaining time is less than half, then flush the ttl
+        if now - start_at >= (report_ttl / 2) then
+            start_at = now
+            report(nil, report_ttl)
+        end
+    end
+
+    if ngx_worker_id() == 0 then
+        local ok, err = ngx_timer_at(0, report, report_ttl)
+        if not ok then
+            core.log.error("failed to create initial timer to report server info: ", err)
+            return
+        end
+    end
+
+    timers.register_timer("plugin#server-info", fn, true)
+
+    core.log.info("timer update the server info ttl, current ttl: ", report_ttl)
+end
+
+
+function _M.destroy()
+    timers.unregister_timer("plugin#server-info", true)
+end
+
+
+return _M

conf/config.yaml.example

@@ -497,6 +497,7 @@ plugins:                           # plugin list (sorted by priority)
   - ai-proxy-multi                 # priority: 998
   #- brotli                        # priority: 996
   - gzip                           # priority: 995
+  - server-info                    # priority: 990
   - traffic-split                  # priority: 966
   - redirect                       # priority: 900
   - response-rewrite               # priority: 899

docs/en/latest/config.json

@@ -91,6 +91,7 @@
             "plugins/gzip",
             "plugins/brotli",
             "plugins/real-ip",
+            "plugins/server-info",
             "plugins/ext-plugin-pre-req",
             "plugins/ext-plugin-post-req",
             "plugins/ext-plugin-post-resp",