feat: server info

apisix/cli/ngx_tpl.lua

@@ -123,6 +123,7 @@ http {
                       .. [=[$prefix/deps/lib/lua/5.1/?.so;;]=]
                       .. [=[{*lua_cpath*};";
 
+    lua_shared_dict internal_status      10m;
     lua_shared_dict plugin-limit-req     10m;
     lua_shared_dict plugin-limit-count   10m;
     lua_shared_dict prometheus-metrics   10m;

apisix/core/utils.lua

@@ -15,6 +15,7 @@
 -- limitations under the License.
 --
 local table    = require("apisix.core.table")
+local log      = require("apisix.core.log")
 local ngx_re   = require("ngx.re")
 local resolver = require("resty.dns.resolver")
 local ipmatcher= require("resty.ipmatcher")
@@ -31,11 +32,16 @@ local ffi_string = ffi.string
 local get_string_buf = base.get_string_buf
 local exiting = ngx.worker.exiting
 local ngx_sleep    = ngx.sleep
+
+local hostname
 local max_sleep_interval = 1
+local max_hostname_len = 256
 
 ffi.cdef[[
     int ngx_escape_uri(char *dst, const char *src,
         size_t size, int type);
+    int gethostname(char *name, size_t len);
+    int strlen(const char *s);
 ]]
 
 
@@ -203,6 +209,26 @@ function _M.validate_header_value(value)
 end
 
 
+function _M.gethostname()
+    if hostname then
+        return hostname
+    end
+
+    local buf = get_string_buf(max_hostname_len)
+
+    if C.gethostname(buf, max_hostname_len) == 0 then
+        buf[max_hostname_len - 1] = str_byte('\0')
+        hostname = ffi_string(buf, ffi.C.strlen(buf))
+
+    else
+        log.alert("ffi.C.gethostname() failed")
+        hostname = "unknown"
+    end
+
+    return hostname
+end
+
+
 local function sleep(sec)
     if sec <= max_sleep_interval then
         return ngx_sleep(sec)

apisix/plugins/server-info.lua

@@ -0,0 +1,235 @@
+--
+-- 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 ngx_time = ngx.time
+local ngx_timer_at = ngx.timer.at
+local type = type
+local ceil = math.ceil
+
+local boot_time = os.time()
+local plugin_name = "server-info"
+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 = 60,
+            maximum = 3600,
+        },
+        report_ttl = {
+            type = "integer",
+            description = "live time for server info in etcd",
+            default = 7200,
+            minimum = 3600,
+            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,
+}
+
+
+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 report(premature, report_ttl)
+    if premature then
+        return
+    end
+
+    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, report_ttl)
+    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()
+    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 threshold = ceil(attr.report_interval / timers.check_interval())
+    local report_ttl = attr.report_ttl
+    local count = 0
+
+    local fn = function()
+        count = count + 1
+        if count == threshold then
+            report(nil, report_ttl)
+            count = 0
+        end
+    end
+
+    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
+
+    timers.register_timer("plugin#server-info", fn, true)
+
+    core.log.info("timer created to report server info, interval: ",
+                  attr.report_interval)
+end
+
+
+function _M.destory()
+    timers.unregister_timer("plugin#server-info", true)
+end
+
+
+return _M

apisix/timers.lua

@@ -21,6 +21,7 @@ local unpack = unpack
 local thread_spawn = ngx.thread.spawn
 local thread_wait = ngx.thread.wait
 
+local check_interval = 0.5
 
 local timers = {}
 
@@ -57,7 +58,12 @@ end
 
 
 function _M.init_worker()
-    local timer, err = core.timer.new("background", background_timer, {check_interval = 0.5})
+    local opts = {
+        check_interval = check_interval,
+        sleep_succ = 0,
+        each_ttl = 0,
+    }
+    local timer, err = core.timer.new("background", background_timer, opts)
     if not timer then
         core.log.error("failed to create background timer: ", err)
         return
@@ -85,4 +91,9 @@ function _M.unregister_timer(name, privileged)
 end
 
 
+function _M.check_interval()
+    return check_interval
+end
+
+
 return _M

conf/config-default.yaml

@@ -238,6 +238,7 @@ plugins:                          # plugin list (sorted in alphabetical order)
   - uri-blocker
   - wolf-rbac
   - zipkin
+  - server-info
 
 stream_plugins:
   - mqtt-proxy
@@ -252,3 +253,6 @@ plugin_attr:
     endpoint_addr: http://127.0.0.1:12800
   prometheus:
     export_uri: /apisix/prometheus/metrics
+  server-info:
+    report_interval: 60 # server info report interval (unit: second)
+    report_ttl: 3600    # live time for server info in etcd (unit: second)