# Telegram Logger handler
<img src="https://raw.githubusercontent.com/krot3232/logos/main/logger_telegram_h.png" width="200">
logger_telegram_h is a custom log handler for the [Erlang/OTP Logger](https://www.erlang.org/docs/26/man/logger.html) that forwards log messages to a Telegram chat via the Telegram Bot API.
It allows you to receive errors, warnings, and other important system events in real time directly in Telegram.
[](https://www.erlang.org)
[](https://hex.pm/packages/logger_telegram_h)
---
## 📥 Installation
The package can be installed by adding `logger_telegram_h` to your list of dependencies
in
`rebar.config`:
```erlang
{deps, [logger_telegram_h]}.
```
## ⚙️ Configuration
Add the handler to your logger configuration:
```erlang
Config=#{
level => all,
config => #{
fun_error_send=>fun logger:log/3,%% Fun(Level, Message, #{domain => [telegram_send_error],telegram_error_msg => Msg,telegram_handler_id => Id })
telegram_send_param=>#{
chat_id=><<"@mychat">>
%,protect_content=>true
%,parse_mode => <<"HTML">>
%,message_thread_id
%,message_effect_id ..
%% see req param -> https://hexdocs.pm/telegram_bot_api/telegram_bot_api.html#sendMessage/2
},
telegram_pool_options=>#{
%% see https://hexdocs.pm/telegram_bot_api/telegram_bot_api_sup.html#start_pool/1
token=><<"1234256789:AAEAAAaAAaVgAAAASSSDDDFFk">> %% Use this token to access the HTTP API, get token @BotFather
}
},
filters => [
{level, {fun logger_filters:level/2, {stop, neq, error}}},
{skip_progress_info, {fun logger_filters:progress/2, stop}},
{ignore_telegram_error_log, {fun logger_filters:domain/2, {stop, sub, [telegram_send_error]}}}
],
formatter =>
{logger_formatter,#{
single_line => true,
legacy_header => false,
chars_limit => 4096,
max_size => 4096,
depth => unlimited,
time_offset => "Z",
time_designator => $\s,
template => [time," [",level,"] ",mfa,":",line," ",pid," ",domain," ",msg]
}
}
},
%%add handler
ok = logger:add_handler(telegram_handler_1, logger_telegram_h, Config).
```
Remove the handler to your logger:
```erlang
ok=logger:remove_handler(telegram_handler_1).
```
Set config logger:
```erlang
ok=logger:set_handler_config(telegram_handler_1, ConfigNew).
```
Update config logger:
```erlang
ok=logger:update_handler_config(telegram_handler_1,formatter,NewFormater).
```
## 🚀 Macros Log
```erlang
-include_lib("kernel/include/logger.hrl").
?LOG_EMERGENCY("example log ~p", [123]).
?LOG_ALERT("example log ~p", [123]).
?LOG_CRITICAL("example log ~p", [123]).
?LOG_ERROR("example log ~p", [123]).
?LOG_WARNING("example log ~p", [123]).
?LOG_NOTICE("example log ~p", [123]).
?LOG_INFO("example log ~p", [123]).
?LOG_DEBUG("example log ~p", [123]).
```
## 🧪 Example
Example `config/sys.config`:
```erlang
[
{kernel, [
{logger_level, all},
{logger, [
{handler, default, logger_std_h,
#{
level => info,
filters => [
{skip_progress_info, {fun logger_filters:progress/2, stop}}
]
}},
{handler, telegram_handler_1, logger_telegram_h,
#{
level => all,
config => #{
fun_error_send=>fun logger:log/3,
fun_rate_limit=>fun logger_telegram_h:rate_limit/2,
telegram_send_param=>#{
chat_id=><<"@mychat">>
},
telegram_pool_options=>#{
token=><<"1111111111:tokenxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx">>
}
},
filters => [
{level, {fun logger_filters:level/2, {stop, neq, error}}},
{skip_progress_info, {fun logger_filters:progress/2, stop}},
{ignore_telegram_error_log, {fun logger_filters:domain/2, {stop, sub, [telegram_send_error]}}}
],
formatter =>
{logger_formatter,#{
single_line => true,
legacy_header => false,
chars_limit => 4096,
max_size => 4096,
depth => unlimited,
time_offset => "Z",
time_designator => $\s,
template => [time," [",level,"] ",mfa,":",line," ",pid," ",domain," ",msg]
}
}
}
},
{handler, handler_telegram_send_error, logger_std_h,
#{
level => debug,
config => #{
file =>"/var/log/telegram_send_error.log"
},
filters => [
{level, {fun logger_filters:level/2, {stop, neq, error}}},
{skip_progress_info, {fun logger_filters:progress/2, stop}},
{ignore_telegram_error_log, {fun logger_filters:domain/2, {stop, not_equal, [telegram_send_error]}}}
],
formatter => {
logger_formatter, #{
single_line => true,time_offset => "Z",time_designator => $\s,
template => [time,":",telegram_handler_id,":",telegram_error_msg," send:",msg,"\n"]}}
}
}
]}
]}
].
```
## 📌 Other
* [Erlang library for developing Telegram Bots](https://hex.pm/packages/telegram_bot_api)
