如何在 ejabberd 中实现模块？

Question

我是 XMPP 服务器 ejabberd 的新手。我通过这个链接在 ubuntu 上安装了 ejabberd：https://docs.ejabberd.im/admin/installation/#install-on-linux。我正在使用 ejabberd-20.07/conf 文件夹中的默认 ejabberd.yml 文件。这是我的 ejabberd.yml 文件：

hosts:
  - "faiqkhan-VirtualBox"

loglevel: 4
log_rotate_size: 10485760
log_rotate_count: 1

certfiles:
  - "/home/faiqkhan/ejabberd-20.07/conf/server.pem"
##  - "/etc/letsencrypt/live/localhost/fullchain.pem"
##  - "/etc/letsencrypt/live/localhost/privkey.pem"

ca_file: "/home/faiqkhan/ejabberd-20.07/conf/cacert.pem"

listen:
  -
    port: 5222
    ip: "::"
    module: ejabberd_c2s
    max_stanza_size: 262144
    shaper: c2s_shaper
    access: c2s
    starttls_required: false
  -
    port: 5269
    ip: "::"
    module: ejabberd_s2s_in
    max_stanza_size: 524288
  -
    port: 5443
    ip: "::"
    module: ejabberd_http
    tls: true
    request_handlers:
      "/admin": ejabberd_web_admin
      "/api": mod_http_api
      "/bosh": mod_bosh
      "/captcha": ejabberd_captcha
      "/upload": mod_http_upload
      "/ws": ejabberd_http_ws
      "/oauth": ejabberd_oauth
  -
    port: 5280
    ip: "::"
    module: ejabberd_http
    request_handlers:
      "/admin": ejabberd_web_admin
  -
    port: 1883
    ip: "::"
    module: mod_mqtt
    backlog: 1000

s2s_use_starttls: optional

acl:
  local:
    user_regexp: ""
  loopback:
    ip:
      - 127.0.0.0/8
      - ::1/128
      - ::FFFF:127.0.0.1/128
  admin:
    user:
      - "admin@faiqkhan-VirtualBox"

access_rules:
  local:
    allow: local
  c2s:
    deny: blocked
    allow: all
  announce:
    allow: admin
  configure:
    allow: admin
  muc_create:
    allow: local
  pubsub_createnode:
    allow: local
  trusted_network:
    allow: local

api_permissions:
  "console commands":
    from:
      - ejabberd_ctl
    who: all
    what: "*"
  "admin access":
    who:
      access:
        allow:
          acl: loopback
          acl: admin
      oauth:
        scope: "ejabberd:admin"
        access:
          allow:
            acl: loopback
            acl: admin
    what:
      - "*"
      - "!stop"
      - "!start"
  "public commands":
    who:
      ip: 127.0.0.1/8
    what:
      - status
      - connected_users_number

shaper:
  normal: 1000
  fast: 50000

shaper_rules:
  max_user_sessions: 10
  max_user_offline_messages:
    5000: admin
    100: all
  c2s_shaper:
    none: admin
    normal: all
  s2s_shaper: fast

max_fsm_queue: 10000

acme:
   contact: "mailto:admin@faiqkhan-VirtualBox"
   ca_url: "https://acme-v02.api.letsencrypt.org/directory"

modules:
  mod_adhoc: {}
  mod_admin_extra: {}
  mod_announce:
    access: announce
  mod_avatar: {}
  mod_blocking: {}
  mod_bosh: {}
  mod_caps: {}
  mod_carboncopy: {}
  mod_client_state: {}
  mod_configure: {}
  mod_disco: {}
  mod_fail2ban: {}
  mod_http_api: {}
  mod_http_upload:
    put_url: https://@HOST@:5443/upload
  mod_last: {}
  mod_mam:
    ## Mnesia is limited to 2GB, better to use an SQL backend
    ## For small servers SQLite is a good fit and is very easy
    ## to configure. Uncomment this when you have SQL configured:
    ## db_type: sql
    assume_mam_usage: true
    default: never
  mod_mqtt: {}
  mod_muc:
    access:
      - allow
    access_admin:
      - allow: admin
    access_create: muc_create
    access_persistent: muc_create
    access_mam:
      - allow
    default_room_options:
      allow_subscription: true  # enable MucSub
      mam: false
  mod_muc_admin: {}
  mod_offline:
    access_max_user_messages: max_user_offline_messages
  mod_ping: {}
  mod_privacy: {}
  mod_private: {}
  mod_proxy65:
    access: local
    max_connections: 5
  mod_pubsub:
    access_createnode: pubsub_createnode
    plugins:
      - flat
      - pep
    force_node_config:
      ## Avoid buggy clients to make their bookmarks public
      storage:bookmarks:
        access_model: whitelist
  mod_push: {}
  mod_push_keepalive: {}
  mod_register:
    ## Only accept registration requests from the "trusted"
    ## network (see access_rules section above).
    ## Think twice before enabling registration from any
    ## address. See the Jabber SPAM Manifesto for details:
    ## https://github.com/ge0rg/jabber-spam-fighting-manifesto
    ip_access: all
  mod_roster:
    versioning: true
  mod_s2s_dialback: {}
  mod_shared_roster: {}
  mod_stream_mgmt:
    resend_on_timeout: if_offline
  mod_vcard: {}
  mod_vcard_xupdate: {}
  mod_version:
    show_os: false
  mod_stanza_ack: {}

我尝试链接问题Ejabberd return message to sender hook / message receipts 中的给定代码，并将我的模块添加到ejabberd.yml 文件中，该文件位于上述代码的最后一行。我创建 mod_stanza_ack.erl 文件并使用命令编译该文件

./erlc mod_stanza_ack.erl

并获得 mod_stanza_ack.beam 文件。我将 mod_stanza_ack.beam 文件处理到所有模块文件都存在的 ejabberd-20.07/lib/ejabberd-20.07/ebin 文件夹中。然后我使用

启动 ejabberd 服务器

./ejabberdctl live

查看日志的命令。模块适用于我，但在服务器端，它总是会因错误而崩溃

**Hook user_send_packet crashed when running mod_stanza_ack:on_user_send_packet/1:
    ** exception error: undefined function mod_stanza_ack:on_user_send_packet/1
       in function  ejabberd_hooks:safe_apply/4 (src/ejabberd_hooks.erl, line 236)
       in call from ejabberd_hooks:run_fold1/4 (src/ejabberd_hooks.erl, line 217)
       in call from ejabberd_c2s:handle_authenticated_packet/2 (src/ejabberd_c2s.erl, line 484)
       in call from xmpp_stream_in:process_authenticated_packet/2 (src/xmpp_stream_in.erl, line 714)
       in call from xmpp_stream_in:handle_info/2 (src/xmpp_stream_in.erl, line 404)
       in call from p1_server:handle_msg/8 (src/p1_server.erl, line 696)
       in call from proc_lib:init_p_do_apply/3 (proc_lib.erl, line 249)**.

我错过了什么吗？还是使用不推荐使用的函数？

Answer 1

好吧，那个示例源代码已经有六年的历史了，从那时起，ejabberd 开发 API 已经发生了变化。我已经更新了示例，它可以编译并使用 ejabberd 20.07 正确启动：

-module(mod_stanza_ack).
-behaviour(gen_mod).

-include("xmpp.hrl").
-include("logger.hrl").
-include("translate.hrl").

-export([start/2, stop/1, mod_options/1, mod_doc/0, depends/2]).
-export([on_user_send_packet/1]).

start(Host, _Opts) ->
    ?INFO_MSG("mod_stanza_ack starting", []),
    ejabberd_hooks:add(user_send_packet, Host, ?MODULE, on_user_send_packet, 0),
    ok.

stop(Host) ->
    ?INFO_MSG("mod_stanza_ack stopping", []),
    ejabberd_hooks:delete(user_send_packet, Host, ?MODULE, on_user_send_packet, 0),
    ok.

on_user_send_packet({#presence{to = To, from = From} = Packet, C2SState}) ->
    ?INFO_MSG("mod_stanza_ack a presence has been sent coming from: ~p", [From]),
    ?INFO_MSG("mod_stanza_ack a presence has been sent to: ~p", [To]),
    ?INFO_MSG("mod_stanza_ack a presence has been sent with the following packet:~n ~p", [Packet]),
    {Packet, C2SState};

on_user_send_packet({#iq{to = To, from = From} = Packet, C2SState}) ->
    ?INFO_MSG("mod_stanza_ack a iq has been sent coming from: ~p", [From]),
    ?INFO_MSG("mod_stanza_ack a iq has been sent to: ~p", [To]),
    ?INFO_MSG("mod_stanza_ack a iq has been sent with the following packet:~n ~p", [Packet]),
    {Packet, C2SState};

on_user_send_packet({#message{to = To, from = From} = Packet, C2SState}) ->
    ?INFO_MSG("mod_stanza_ack a message has been sent coming from: ~p", [From]),
    ?INFO_MSG("mod_stanza_ack a message has been sent to: ~p", [To]),
    ?INFO_MSG("mod_stanza_ack a message has been sent with the following packet:~n ~p", [Packet]),
    {Packet, C2SState}.

depends(_Host, _Opts) ->
    [].

mod_options(_Host) ->
    [].

mod_doc() ->
    #{desc =>
          ?T("This an example module.")}.

按照您详细的分步安装指南，我遇到了两个问题，我在这里描述了它们以及如何解决它们：

1. 编译时缺少头文件。

我将 mod_stanza_ack.erl 复制到 ejabberd-20.07/bin，然后运行这个命令：

$ ./erlc mod_stanza_ack.erl
mod_stanza_ack.erl:4: can't find include file "xmpp.hrl"
mod_stanza_ack.erl:5: can't find include file "logger.hrl"
mod_stanza_ack.erl:6: can't find include file "translate.hrl"
mod_stanza_ack.erl:12: undefined macro 'INFO_MSG/2'
mod_stanza_ack.erl:17: undefined macro 'INFO_MSG/2'
mod_stanza_ack.erl:22: undefined macro 'INFO_MSG/2'
mod_stanza_ack.erl:47: undefined macro 'T/1'
mod_stanza_ack.erl:8: function mod_doc/0 undefined
mod_stanza_ack.erl:8: function start/2 undefined
mod_stanza_ack.erl:8: function stop/1 undefined
mod_stanza_ack.erl:9: function on_user_send_packet/1 undefined

解决方法很简单：提供头文件的路径：

$ ./erlc -I ../lib/ejabberd-20.07/include/ -I ../lib/xmpp-1.4.9/include/ -I ../lib/fast_xml-1.1.43/include/ mod_stanza_ack.erl

这样文件就被正确编译了。

1. 源代码中的 INFO_MSG 不会在 ejabberd 日志文件或“ejabberdctl live”控制台中生成日志消息。

这是因为我们没有告诉编译器使用 LAGER 库。解决方案很简单：在模块编译中包含 -DLAGER。所以，这是完美的编译调用：

$ ./erlc -I ../lib/ejabberd-20.07/include/ -I ../lib/xmpp-1.4.9/include/ -I ../lib/fast_xml-1.1.43/include/ -DLAGER mod_stanza_ack.erl

现在，您将生成的 mod_stanza_ack.beam 与所有其他 ejabberd 光束文件一起复制，启用 ejabberd.yml 中的模块，然后重新启动 ejabberd，一切都会按预期工作