emqtt 试用（四）emq 的主题访问控制 acl.conf

访问控制(ACL)

EMQ 消息服务器通过 ACL(Access Control List) 实现 MQTT 客户端访问控制。

ACL 访问控制规则定义:

允许(Allow)|拒绝(Deny) 谁(Who) 订阅(Subscribe)|发布(Publish) 主题列表(Topics)

MQTT 客户端发起订阅/发布请求时，EMQ 消息服务器的访问控制模块，会逐条匹配 ACL 规则，直到匹配成功为止:

          ---------              ---------              ---------
Client -> | Rule1 | --nomatch--> | Rule2 | --nomatch--> | Rule3 | --> Default
          ---------              ---------              ---------
              |                      |                      |
            match                  match                  match
             \|/                    \|/                    \|/
        allow | deny           allow | deny           allow | deny

默认访问控制设置

EMQ 消息服务器默认访问控制，在 etc/emq.conf 中设置:

## ACL nomatch
mqtt.acl_nomatch = allow

## Default ACL File
mqtt.acl_file = etc/acl.conf

ACL 规则定义在 etc/acl.conf，EMQ 启动时加载到内存:

%% Allow 'dashboard' to subscribe '$SYS/#'
{allow, {user, "dashboard"}, subscribe, ["$SYS/#"]}.

%% Allow clients from localhost to subscribe any topics
{allow, {ipaddr, "127.0.0.1"}, pubsub, ["$SYS/#", "#"]}.

%% Deny clients to subscribe '$SYS#' and '#'
{deny, all, subscribe, ["$SYS/#", {eq, "#"}]}.

%% Allow all by default
{allow, all}.

HTTP 插件访问控制

注解

开启 HTTP 插件后，会终结 ACL 链

HTTP API 实现访问控制: https://github.com/emqtt/emq_auth_http

配置 etc/plugins/emq_auth_http.conf, 启用 HTTP 认证插件后:

## 'access' parameter: sub = 1, pub = 2
auth.http.acl_req = http://127.0.0.1:8080/mqtt/acl
auth.http.acl_req.method = get
auth.http.acl_req.params = access=%A,username=%u,clientid=%c,ipaddr=%a,topic=%t

MySQL 插件访问控制

MySQL 插件访问控制，通过 mqtt_acl 表定义 ACL 规则:

CREATE TABLE `mqtt_acl` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `allow` int(1) DEFAULT NULL COMMENT '0: deny, 1: allow',
  `ipaddr` varchar(60) DEFAULT NULL COMMENT 'IpAddress',
  `username` varchar(100) DEFAULT NULL COMMENT 'Username',
  `clientid` varchar(100) DEFAULT NULL COMMENT 'ClientId',
  `access` int(2) NOT NULL COMMENT '1: subscribe, 2: publish, 3: pubsub',
  `topic` varchar(100) NOT NULL DEFAULT '' COMMENT 'Topic Filter',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO mqtt_acl (id, allow, ipaddr, username, clientid, access, topic)
VALUES
    (1,1,NULL,'$all',NULL,2,'#'),
    (2,0,NULL,'$all',NULL,1,'$SYS/#'),
    (3,0,NULL,'$all',NULL,1,'eq #'),
    (5,1,'127.0.0.1',NULL,NULL,2,'$SYS/#'),
    (6,1,'127.0.0.1',NULL,NULL,2,'#'),
    (7,1,NULL,'dashboard',NULL,1,'$SYS/#');

etc/plugins/emq_auth_mysql.conf 配置 ‘acl_query’ 与 ‘acl_nomatch’:

## ACL Query Command
auth.mysql.acl_query = select allow, ipaddr, username, clientid, access, topic from mqtt_acl where ipaddr = '%a' or username = '%u' or username = '$all' or clientid = '%c'

Postgre 插件访问控制

PostgreSQL 插件访问控制，通过 mqtt_acl 表定义 ACL 规则:

CREATE TABLE mqtt_acl (
  id SERIAL primary key,
  allow integer,
  ipaddr character varying(60),
  username character varying(100),
  clientid character varying(100),
  access  integer,
  topic character varying(100)
);

INSERT INTO mqtt_acl (id, allow, ipaddr, username, clientid, access, topic)
VALUES
    (1,1,NULL,'$all',NULL,2,'#'),
    (2,0,NULL,'$all',NULL,1,'$SYS/#'),
    (3,0,NULL,'$all',NULL,1,'eq #'),
    (5,1,'127.0.0.1',NULL,NULL,2,'$SYS/#'),
    (6,1,'127.0.0.1',NULL,NULL,2,'#'),
    (7,1,NULL,'dashboard',NULL,1,'$SYS/#');

etc/plugins/emq_auth_pgsql.conf 设置 ‘acl_query’ 与 ‘acl_nomatch’:

## ACL Query. Comment this query, the acl will be disabled.
auth.pgsql.acl_query = select allow, ipaddr, username, clientid, access, topic from mqtt_acl where ipaddr = '%a' or username = '%u' or username = '$all' or clientid = '%c'

Redis 插件访问控制

Redis Hash 存储一个 MQTT 客户端的访问控制规则:

HSET mqtt_acl:<username> topic1 1
HSET mqtt_acl:<username> topic2 2
HSET mqtt_acl:<username> topic3 3

etc/plugins/emq_auth_redis.conf 配置 ‘acl_cmd’ 与 ‘acl_nomatch’:

## ACL Query Command
auth.redis.acl_cmd = HGETALL mqtt_acl:%u

MongoDB 插件访问控制

MongoDB 数据库创建 mqtt_acl 集合:

{
    username: "username",
    clientid: "clientid",
    publish: ["topic1", "topic2", ...],
    subscribe: ["subtop1", "subtop2", ...],
    pubsub: ["topic/#", "topic1", ...]
}

mqtt_acl 集合插入数据，例如:

db.mqtt_acl.insert({username: "test", publish: ["t/1", "t/2"], subscribe: ["user/%u", "client/%c"]})
db.mqtt_acl.insert({username: "admin", pubsub: ["#"]})

etc/plugins/emq_auth_mongo.conf 配置 ‘acl_query’ 与 ‘acl_nomatch’:

## acl_query
auth.mongo.acl_query.collection = mqtt_user

auth.mongo.acl_query.selector = username=%u