feat(xds): using data written by xds to control dp behavior

apisix/cli/ngx_tpl.lua

@@ -244,7 +244,8 @@ http {
     {% end %}
 
     {% if config_center == "xds" then %}
-    lua_shared_dict xds-route-config  10m;
+    lua_shared_dict xds-config  10m;
+    lua_shared_dict xds-config-version  1m;
     {% end %}
 
     # for custom shared dict

apisix/core/config_xds.lua

@@ -15,46 +15,72 @@
 -- limitations under the License.
 --
 
---- Get configuration form ngx.shared.DICT.
+--- Get configuration form ngx.shared.DICT
 --
 -- @module core.config_xds
 
-local base              = require("resty.core.base")
 local config_local      = require("apisix.core.config_local")
+local string            = require("apisix.core.string")
+local log               = require("apisix.core.log")
+local json              = require("apisix.core.json")
+local ngx_sleep         = require("apisix.core.utils").sleep
+local check_schema      = require("apisix.core.schema").check
+local new_tab           = require("table.new")
 local table             = table
+local insert_tab        = table.insert
 local error             = error
-local is_http           = ngx.config.subsystem == "http"
+local pcall             = pcall
+local tostring          = tostring
+local setmetatable      = setmetatable
 local io                = io
 local io_open           = io.open
 local io_close          = io.close
 local package           = package
-local new_tab           = base.new_tab
+local ipairs            = ipairs
+local type              = type
+local sub_str           = string.sub
 local ffi               = require ("ffi")
 local C                 = ffi.C
-local route_config     = ngx.shared["xds-route-config"]
+local config            = ngx.shared["xds-config"]
+local conf_ver          = ngx.shared["xds-config-version"]
+local is_http           = ngx.config.subsystem == "http"
 local ngx_re_match      = ngx.re.match
 local ngx_re_gmatch     = ngx.re.gmatch
+local ngx_timer_every   = ngx.timer.every
+local ngx_timer_at      = ngx.timer.at
+local exiting           = ngx.worker.exiting
+local ngx_time          = ngx.time
 
-local xds_lib_name = "libxds.so"
-
+local xds_lib_name      = "libxds.so"
 
 local process
 if is_http then
     process = require("ngx.process")
 end
 
-
 ffi.cdef[[
-extern void initial(void* route_zone_ptr);
+typedef unsigned int  useconds_t;
+
+extern void initial(void* config_zone, void* version_zone);
+int usleep(useconds_t usec);
 ]]
 
+local created_obj  = {}
 
 local _M = {
     version = 0.1,
     local_conf = config_local.local_conf,
 }
 
 
+local mt = {
+    __index = _M,
+    __tostring = function(self)
+        return " xds key: " .. self.key
+    end
+}
+
+
 -- todo: refactor this function in chash.lua and radixtree.lua
 local function load_shared_lib(lib_name)
     local cpath = package.cpath
@@ -101,18 +127,248 @@ local function load_libxds(lib_name)
               table.concat(tried_paths, '\r\n', 1, #tried_paths))
     end
 
-    local route_zone = C.ngx_http_lua_ffi_shdict_udata_to_zone(route_config[1])
-    local route_shd_cdata = ffi.cast("void*", route_zone)
-    xdsagent.initial(route_shd_cdata)
+    local config_zone = C.ngx_http_lua_ffi_shdict_udata_to_zone(config[1])
+    local config_shd_cdata = ffi.cast("void*", config_zone)
+
+    local conf_ver_zone = C.ngx_http_lua_ffi_shdict_udata_to_zone(conf_ver[1])
+    local conf_ver_shd_cdata = ffi.cast("void*", conf_ver_zone)
+
+    xdsagent.initial(config_shd_cdata, conf_ver_shd_cdata)
+end
+
+
+local latest_version
+local function sync_data(self)
+    if self.conf_version == latest_version then
+        return true
+    end
+
+    if self.values then
+        for _, val in ipairs(self.values) do
+            if val and val.clean_handlers then
+                for _, clean_handler in ipairs(val.clean_handlers) do
+                    clean_handler(val)
+                end
+                val.clean_handlers = nil
+            end
+        end
+        self.values = nil
+        self.values_hash = nil
+    end
+
+    local keys = config:get_keys(0)
+
+    if not keys or #keys <= 0 then
+        -- xds did not write any data to shdict
+        return false, "no keys"
+    end
+
+    self.values = new_tab(#keys, 0)
+    self.values_hash = new_tab(0, #keys)
+
+    for _, key in ipairs(keys) do
+        if string.has_prefix(key, self.key) then
+            local data_valid = true
+            local conf_str = config:get(key, 0)
+            local conf, err = json.decode(conf_str)
+            if not conf then
+                data_valid = false
+                log.error("decode the conf of [", key, "] failed, err: ", err,
+                          ", conf_str: ", conf_str)
+            end
+
+            if not self.single_item and type(conf) ~= "table" then
+                data_valid = false
+                log.error("invalid conf of [", key, "], conf: ", conf,
+                          ", it should be an object")
+            end
+
+            if data_valid and self.item_schema then
+                local ok, err = check_schema(self.item_schema, conf)
+                if not ok then
+                    data_valid = false
+                    log.error("failed to check the conf of [", key, "] err:", err)
+                end
+            end
+
+            if data_valid and self.checker then
+                local ok, err = self.checker(conf)
+                if not ok then
+                    data_valid = false
+                    log.error("failed to check the conf of [", key, "] err:", err)
+                end
+            end
+
+            if data_valid then
+                if not conf.id then
+                    conf.id = sub_str(key, #self.key + 2, #key + 1)
+                    log.warn("the id of [", key, "] is nil, use the id: ", conf.id)
+                end
+
+                local conf_item = {value = conf, modifiedIndex = latest_version,
+                                   key = key}
+                insert_tab(self.values, conf_item)
+                self.values_hash[conf.id] = #self.values
+                conf_item.clean_handlers = {}
+
+                if self.filter then
+                    self.filter(conf_item)
+                end
+            end
+        end
+    end
+
+    self.conf_version = latest_version
+    return true
 end
 
 
+local function _automatic_fetch(premature, self)
+    if premature then
+        return
+    end
+
+    local i = 0
+    while not exiting() and self.running and i <= 32 do
+        i = i + 1
+        local ok, ok2, err = pcall(sync_data, self)
+        if not ok then
+            err = ok2
+            log.error("failed to fetch data from xds: ",
+                      err, ", ", tostring(self))
+            ngx_sleep(3)
+            break
+        elseif not ok2 and err then
+            -- todo: handler other error
+            if err ~= "wait for more time" and err ~= "no keys" and self.last_err ~= err then
+                log.error("failed to fetch data from xds, ", err, ", ", tostring(self))
+            end
+
+            if err ~= self.last_err then
+                self.last_err = err
+                self.last_err_time = ngx_time()
+            else
+                if ngx_time() - self.last_err_time >= 30 then
+                    self.last_err = nil
+                end
+            end
+            ngx_sleep(0.5)
+        elseif not ok2 then
+            ngx_sleep(0.05)
+        else
+            ngx_sleep(0.1)
+        end
+    end
+
+    if not exiting() and self.running then
+        ngx_timer_at(0, _automatic_fetch, self)
+    end
+end
+
+
+local function fetch_version(premature)
+    if premature then
+        return
+    end
+
+    local version = conf_ver:get("version")
+
+    if not version then
+        return
+    end
+
+    if version ~= latest_version then
+        latest_version = version
+    end
+end
+
+
+function _M.new(key, opts)
+    local automatic = opts and opts.automatic
+    local item_schema = opts and opts.item_schema
+    local filter_fun = opts and opts.filter
+    local single_item = opts and opts.single_item
+    local checker = opts and opts.checker
+
+
+    local obj = setmetatable({
+        automatic = automatic,
+        item_schema = item_schema,
+        checker = checker,
+        sync_times = 0,
+        running = true,
+        conf_version = 0,
+        values = nil,
+        routes_hash = nil,
+        prev_index = nil,
+        last_err = nil,
+        last_err_time = nil,
+        key = key,
+        single_item = single_item,
+        filter = filter_fun,
+    }, mt)
+
+    if automatic then
+        if not key then
+            return nil, "missing `key` argument"
+        end
+
+        -- blocking until xds completes initial configuration
+        while true do
+            C.usleep(0.1)
+            fetch_version()
+            if latest_version then
+                break
+            end
+        end
+
+        local ok, ok2, err = pcall(sync_data, obj)
+        if not ok then
+            err = ok2
+        end
+
+        if err then
+            log.error("failed to fetch data from xds ",
+                      err, ", ", key)
+        end
+
+        ngx_timer_at(0, _automatic_fetch, obj)
+    end
+
+    if key then
+        created_obj[key] = obj
+    end
+
+    return obj
+end
+
+
+function _M.get(self, key)
+    if not self.values_hash then
+        return
+    end
+
+    local arr_idx = self.values_hash[tostring(key)]
+    if not arr_idx then
+        return nil
+    end
+
+    return self.values[arr_idx]
+end
+
+
+function _M.fetch_created_obj(key)
+    return created_obj[key]
+end
+
 
 function _M.init_worker()
     if process.type() == "privileged agent" then
         load_libxds(xds_lib_name)
     end
 
+    ngx_timer_every(1, fetch_version)
+
     return true
 end
 

apisix/init.lua

@@ -116,12 +116,6 @@ function _M.http_init_worker()
 
     require("apisix.debug").init_worker()
 
-    plugin.init_worker()
-    router.http_init_worker()
-    require("apisix.http.service").init_worker()
-    plugin_config.init_worker()
-    require("apisix.consumer").init_worker()
-
     if core.config.init_worker then
         local ok, err = core.config.init_worker()
         if not ok then
@@ -130,6 +124,12 @@ function _M.http_init_worker()
         end
     end
 
+    plugin.init_worker()
+    router.http_init_worker()
+    require("apisix.http.service").init_worker()
+    plugin_config.init_worker()
+    require("apisix.consumer").init_worker()
+
     apisix_upstream.init_worker()
     require("apisix.plugins.ext-plugin.init").init_worker()
 

t/APISIX.pm

@@ -509,7 +509,8 @@ _EOC_
     lua_shared_dict ext-plugin 1m;
     lua_shared_dict kubernetes 1m;
     lua_shared_dict tars 1m;
-    lua_shared_dict xds-route-config 1m;
+    lua_shared_dict xds-config 1m;
+    lua_shared_dict xds-config-version 1m;
 
     proxy_ssl_name \$upstream_host;
     proxy_ssl_server_name on;