install & configure mod_offline_post in ejabberd 20.07 version

Question

I have installed and used mod_offline_http_post module in 20.07 version and was able to get push notifications for individual users. But this module doesn't support MUC rooms. I wanted to get push notifications for users who have subscribed to a MUC room and is currently offline. I found that mod_offline_post module does this. But I wasn't able to configure [mod_offline_post] with ejabberd 20.07 version. For compiling and installing I have followed these instructions https://docs.ejabberd.im/developer/extending-ejabberd/modules/.

After doing this, when i try to configure mod_offline_post in ejabberd.yml it gives me an error mod_offline_post is not a ejabberd module.

Answer 1

Well, that module is two years old, and is not up-to-date with ejabberd modules API requirements, so it isn't an ejabberd module.

I've updated its source code to compile correctly with newest ejabberd. I have not checked it actually works.

Those steps allow to download, fix and install the module:

mkdir -p $HOME/.ejabberd-modules/sources/

cd $HOME/.ejabberd-modules/sources/

git clone https://github.com/k9428/mod_offline_post.git

cd mod_offline_post

Then put here a file called update.patch with this content:

From bb7355f5abf558365e68b91e996b303beeb7576e Mon Sep 17 00:00:00 2001
From: Badlop <[email protected]>
Date: Mon, 5 Oct 2020 18:07:29 +0200
Subject: [PATCH] Update to compile with recent ejabberd

---
 src/mod_offline_post.erl | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/mod_offline_post.erl b/src/mod_offline_post.erl
index a5e6af8..dccf419 100644
--- a/src/mod_offline_post.erl
+++ b/src/mod_offline_post.erl
@@ -8,11 +8,34 @@
     send_notice/1,
     getbody/1]).
 
+-export([mod_options/1, depends/2, mod_opt_type/1, mod_doc/0]).
+
 -define(PROCNAME, ?MODULE).
 
 -include("xmpp.hrl").
+-include("translate.hrl").
 -include("logger.hrl").
 
+depends(_Host, _Opts) ->
+    [].
+
+mod_opt_type(post_url) ->
+    econf:binary();
+mod_opt_type(app_id) ->
+    econf:binary();
+mod_opt_type(api_key) ->
+    econf:binary().
+
+mod_options(_Host) ->
+    [{post_url, <<"">>},
+     {app_id, <<"">>},
+     {api_key, <<"">>}
+    ].
+
+mod_doc() ->
+    #{desc =>
+          ?T("This module is for offline post.")}.
+
 start(Host, Opts) ->
    ?INFO_MSG("Starting mod_offline_post", [] ),
    register(?PROCNAME,spawn(?MODULE, init, [Host, Opts])),  
@@ -50,11 +73,11 @@ send_notice({Action,Packet}) ->
    % ToId = binary_to_list(fxml:get_tag_attr_s(list_to_binary("toId"), CustomData)),
    % IsPhoto = binary_to_list(fxml:get_tag_attr_s(list_to_binary("isPhoto"), CustomData)),
    
-   PostUrl = gen_mod:get_module_opt(To#jid.lserver, ?MODULE, post_url,fun(S) -> iolist_to_binary(S) end, list_to_binary("")),
+   PostUrl = gen_mod:get_module_opt(To#jid.lserver, ?MODULE, post_url),
    
    %% Configure your own options passed to module
-   AppId = gen_mod:get_module_opt(To#jid.lserver, ?MODULE, app_id, fun(S) -> iolist_to_binary(S) end, list_to_binary("")),
-   ApiKey = gen_mod:get_module_opt(To#jid.lserver, ?MODULE, api_key, fun(S) -> iolist_to_binary(S) end, list_to_binary("")),
+   AppId = gen_mod:get_module_opt(To#jid.lserver, ?MODULE, app_id),
+   ApiKey = gen_mod:get_module_opt(To#jid.lserver, ?MODULE, api_key),
    
    Data = string:join(["to=", ToUsername, "&from=", FromUsername, "&type=", Type, "&body=", FinalBody], ""),
    Request = {binary_to_list(PostUrl), [{"X-Parse-Application-Id", binary_to_list(AppId)}, {"X-Parse-REST-API-Key", binary_to_list(ApiKey)}], "application/x-www-form-urlencoded", Data},
-- 
2.20.1

And finally, apply the patch, and install the module:

git am -3 update.patch
S'està aplicant: Update to compile with recent ejabberd

ejabberdctl modules_available
mod_offline_post        Forwards messages that are sent to offline users through a post request to a configurable url

ejabberdctl module_install mod_offline_post
/home/badlop/.ejabberd-modules/sources/mod_offline_post/src/mod_offline_post.erl:33: Warning: variable 'Action' is unused
/home/badlop/.ejabberd-modules/sources/mod_offline_post/src/mod_offline_post.erl:45: Warning: variable 'El' is unused