feature(limit-count): supported global limit count with redis server.

.travis.yml

@@ -31,6 +31,9 @@ addons:
   homebrew:
     update: true
 
+services:
+ - redis-server
+
 cache:
   directories:
   - build-cache

Makefile

@@ -132,6 +132,9 @@ install:
 	$(INSTALL) -d $(INST_LUADIR)/apisix/lua/apisix/plugins/grpc-transcode/
 	$(INSTALL) lua/apisix/plugins/grpc-transcode/*.lua $(INST_LUADIR)/apisix/lua/apisix/plugins/grpc-transcode/
 
+	$(INSTALL) -d $(INST_LUADIR)/apisix/lua/apisix/plugins/limit-count/
+	$(INSTALL) lua/apisix/plugins/limit-count/*.lua $(INST_LUADIR)/apisix/lua/apisix/plugins/limit-count/
+
 	$(INSTALL) -d $(INST_LUADIR)/apisix/lua/apisix/plugins
 	$(INSTALL) lua/apisix/plugins/*.lua $(INST_LUADIR)/apisix/lua/apisix/plugins/
 

doc/plugins/limit-count-cn.md

@@ -5,15 +5,22 @@
 在指定的时间范围内，限制总的请求个数。并且在 HTTP 响应头中返回剩余可以请求的个数。
 
 ### 参数
-* `count`：指定时间窗口内的请求数量阈值
-* `time_window`：时间窗口的大小（以秒为单位），超过这个时间就会重置
-* `rejected_code`：当请求超过阈值被拒绝时，返回的 HTTP 状态码，默认是 503
-* `key`：是用来做请求计数的依据，当前接受的 key 有："remote_addr"(客户端IP地址), "server_addr"(服务端 IP 地址), 请求头中的"X-Forwarded-For" 或 "X-Real-IP"。
+
+|名称           |可选项  |说明|
+|---------     |--------|-----------|
+|count         |必选     |指定时间窗口内的请求数量阈值|
+|time_window   |必选     |时间窗口的大小（以秒为单位），超过这个时间就会重置|
+|key           |必选     |是用来做请求计数的依据，当前接受的 key 有: "remote_addr", "server_addr", "http_x_real_ip", "http_x_forwarded_for"。|
+|rejected_code |可选     |T当请求超过阈值被拒绝时，返回的 HTTP 状态码，默认是 503|
+|policy        |可选     |用于检索和增加限制的速率限制策略。可选的值有：`local`(计数器被以内存方式保存在节点本地) 和 `redis`(计数器保存在 Redis 服务节点上，从而可以跨节点共享结果，通常用它来完成全局限速).|
+|redis.host    |可选     |当使用 `redis` 限速策略时，该属性是 Redis 服务节点的地址。|
+|redis.port    |可选     |当使用 `redis` 限速策略时，该属性是 Redis 服务节点的端口，默认值 6379。|
+|redis.timeout |可选     |当使用 `redis` 限速策略时，该属性是 Redis 服务节点的通讯超时时间，默认值 1000 ms（1 秒）。|
 
 ### 示例
 
 #### 开启插件
-下面是一个示例，在指定的 route 上开启了 limit count 插件:
+下面是一个示例，在指定的 `route` 上开启了 `limit count` 插件:
 
 ```shell
 curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
@@ -42,6 +49,37 @@ curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
 然后在 route 页面中添加 limit-count 插件：
 ![](../images/plugin/limit-count-2.png)
 
+如果你需要一个集群级别的流量控制，我们可以借助 redis server 来完成。不同的 APISIX 节点之间将共享流量限速结果，实现集群流量限速。
+
+请看下面例子：
+
+```shell
+curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
+{
+    "uri": "/index.html",
+    "plugins": {
+        "limit-count": {
+            "count": 2,
+            "time_window": 60,
+            "rejected_code": 503,
+            "key": "remote_addr",
+            "policy": "redis",
+            "redis": {
+                "host": "127.0.0.1",
+                "port": 6379,
+                "timeout": 1001
+            }
+        }
+    },
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "39.97.63.215:80": 1
+        }
+    }
+}'
+```
+
 #### 测试插件
 上述配置限制了 60 秒内只能访问 2 次，前两次访问都会正常访问：
 ```shell
@@ -76,10 +114,10 @@ Server: APISIX web server
 </html>
 ```
 
-这就表示 limit count 插件生效了。
+这就表示 `limit count` 插件生效了。
 
 #### 移除插件
-当你想去掉 limit count 插件的时候，很简单，在插件的配置中把对应的 json 配置删除即可，无须重启服务，即刻生效：
+当你想去掉 `limit count` 插件的时候，很简单，在插件的配置中把对应的 json 配置删除即可，无须重启服务，即刻生效：
 
 ```shell
 curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
@@ -95,4 +133,4 @@ curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
 }'
 ```
 
-现在就已经移除了 limit count 插件了。其他插件的开启和移除也是同样的方法。
+现在就已经移除了 `limit count` 插件了。其他插件的开启和移除也是同样的方法。

doc/plugins/limit-count.md

@@ -2,15 +2,24 @@
 # limit-count
 
 ### Parameters
-* `count`: is the specified number of requests threshold.
-* `time_window`: is the time window in seconds before the request count is reset.
-* `rejected_code`: The HTTP status code returned when the request exceeds the threshold is rejected. The default is 503.
-* `key`: is the user specified key to limit the rate, now accept those as key: "remote_addr"(client's IP), "server_addr"(server's IP), "X-Forwarded-For/X-Real-IP" in request header.
+
+|name          |option  |description|
+|---------     |--------|-----------|
+|count         |required|the specified number of requests threshold.|
+|time_window   |required|the time window in seconds before the request count is reset.|
+|key           |required|the user specified key to limit the rate. Here is fully key list: "remote_addr", "server_addr", "http_x_real_ip", "http_x_forwarded_for".|
+|rejected_code |optional|The HTTP status code returned when the request exceeds the threshold is rejected. The default is 503.|
+|policy        |optional|The rate-limiting policies to use for retrieving and incrementing the limits. Available values are `local`(the counters will be stored locally in-memory on the node) and `redis`(counters are stored on a Redis server and will be shared across the nodes, usually used it to do the global speed limit).|
+|redis.host    |optional|When using the `redis` policy, this property specifies the address of the Redis server.|
+|redis.port    |optional|When using the `redis` policy, this property specifies the port of the Redis server. The default port is 6379.|
+|redis.timeout |optional|When using the `redis` policy, this property specifies the timeout in milliseconds of any command submitted to the Redis server. The default timeout is 1000 ms(1 second).|
+
 
 ### example
 
 #### enable plugin
-Here's an example, enable the limit count plugin on the specified route:
+
+Here's an example, enable the `limit count` plugin on the specified route:
 
 ```shell
 curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
@@ -39,6 +48,37 @@ You can open dashboard with a browser: `http://127.0.0.1:9080/apisix/dashboard/`
 Then add limit-count plugin:
 ![](../images/plugin/limit-count-2.png)
 
+If you need a cluster-level precision traffic limit, then we can do it with the redis server. The rate limit of the traffic will be shared between different APISIX nodes to limit the rate of cluster traffic.
+
+Here is the example:
+
+```shell
+curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
+{
+    "uri": "/index.html",
+    "plugins": {
+        "limit-count": {
+            "count": 2,
+            "time_window": 60,
+            "rejected_code": 503,
+            "key": "remote_addr",
+            "policy": "redis",
+            "redis": {
+                "host": "127.0.0.1",
+                "port": 6379,
+                "timeout": 1001
+            }
+        }
+    },
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "39.97.63.215:80": 1
+        }
+    }
+}'
+```
+
 #### test plugin
 The above configuration limits access to only 2 times in 60 seconds. The first two visits will be normally:
 ```shell
@@ -74,10 +114,10 @@ Server: APISIX web server
 </html>
 ```
 
-This means that the limit count plugin is in effect.
+This means that the `limit count` plugin is in effect.
 
 #### disable plugin
-When you want to disable the limit count plugin, it is very simple,
+When you want to disable the `limit count` plugin, it is very simple,
  you can delete the corresponding json configuration in the plugin configuration,
   no need to restart the service, it will take effect immediately:
 ```shell
@@ -94,4 +134,4 @@ curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -d '
 }'
 ```
 
-The limit count plugin has been disabled now. It works for other plugins.
+The `limit count` plugin has been disabled now. It works for other plugins.

lua/apisix/plugins/limit-count.lua

@@ -1,40 +1,93 @@
-local limit_count_new = require("resty.limit.count").new
+local limit_local_new = require("resty.limit.count").new
 local core = require("apisix.core")
 local plugin_name = "limit-count"
+local limit_redis_new
+do
+    local redis_src = "apisix.plugins.limit-count.limit-count-redis"
+    limit_redis_new = require(redis_src).new
+end
 
 
 local schema = {
     type = "object",
     properties = {
         count = {type = "integer", minimum = 0},
         time_window = {type = "integer",  minimum = 0},
-        key = {type = "string",
+        key = {
+            type = "string",
             enum = {"remote_addr", "server_addr", "http_x_real_ip",
                     "http_x_forwarded_for"},
         },
         rejected_code = {type = "integer", minimum = 200, maximum = 600},
+        policy = {
+            type = "string",
+            enum = {"local", "redis"},
+        },
+        redis = {
+            type = "object",
+            properties = {
+                host = {
+                    type = "string", minLength = 2
+                },
+                port = {
+                    type = "integer", minimum = 1
+                },
+                timeout = {
+                    type = "integer", minimum = 1
+                },
+            },
+            required = {"host"},
+        },
     },
     additionalProperties = false,
     required = {"count", "time_window", "key", "rejected_code"},
 }
 
 
 local _M = {
-    version = 0.1,
-    priority = 1002,        -- TODO: add a type field, may be a good idea
+    version = 0.2,
+    priority = 1002,
     name = plugin_name,
     schema = schema,
 }
 
 
 function _M.check_schema(conf)
-    return core.schema.check(schema, conf)
+    local ok, err = core.schema.check(schema, conf)
+    if not ok then
+        return false, err
+    end
+
+    if not conf.policy then
+        conf.policy = "local"
+    end
+
+    if conf.policy == "redis" then
+        if not conf.redis then
+            return false, "missing valid redis options"
+        end
+
+        conf.redis.port = conf.redis.port or 6379
+        conf.redis.timeout = conf.redis.timeout or 1000
+    end
+
+    return true
 end
 
 
 local function create_limit_obj(conf)
     core.log.info("create new limit-count plugin instance")
-    return limit_count_new("plugin-limit-count", conf.count, conf.time_window)
+
+    if not conf.policy or conf.policy == "local" then
+        return limit_local_new("plugin-" .. plugin_name, conf.count,
+                               conf.time_window)
+    end
+
+    if conf.policy == "redis" then
+        return limit_redis_new(conf.count, conf.time_window, conf.redis)
+    end
+
+    return nil
 end
 
 

lua/apisix/plugins/limit-count/limit-count-redis.lua

@@ -0,0 +1,67 @@
+local redis_new = require("resty.redis").new
+local core = require("apisix.core")
+
+
+local _M = {}
+
+
+local mt = {
+    __index = _M
+}
+
+
+function _M.new(limit, window, redis_conf)
+    assert(limit > 0 and window > 0)
+
+    local self = {limit = limit, window = window, redis = redis_conf}
+    return setmetatable(self, mt)
+end
+
+
+function _M.incoming(self, key)
+    local red = redis_new()
+    local conf = self.redis
+    local timeout = conf.timeout or 1000    -- 1sec
+    core.log.info("ttl key: ", key, " timeout: ", timeout)
+
+    red:set_timeouts(timeout, timeout, timeout)
+
+    local ok, err = red:connect(conf.host, conf.port or 6379)
+    if not ok then
+        return false, err
+    end
+
+    local limit = self.limit
+    local window = self.window
+    local remaining
+
+    local ret, err = red:ttl(key)
+    core.log.info("ttl key: ", key, " ret: ", ret, " err: ", err)
+    if ret < 0 then
+        ret, err = red:set(key, limit -1, "EX", window, "NX")
+        if not ret then
+            return nil, err
+        end
+
+        return 0, limit -1
+    end
+
+    remaining, err = red:incrby(key, -1)
+    if not remaining then
+        return nil, err
+    end
+
+    local ok, err = red:set_keepalive(10000, 100)
+    if not ok then
+        return nil, err
+    end
+
+    if remaining < 0 then
+        return nil, "rejected"
+    end
+
+    return 0, remaining
+end
+
+
+return _M

t/node/merge-route.t

@@ -215,5 +215,5 @@ location /t {
 --- request
 GET /t
 --- error_log eval
-[qr/merge_service_route.*"time_window":60,"rejected_code":503/,
-qr/merge_service_route.*"time_window":60,"rejected_code":503/]
+[qr/merge_service_route.*"time_window":60,/,
+qr/merge_service_route.*"time_window":60,/]