A logger backend for Telegram.

Add :logger_telegram_backend to your list of dependencies in mix.exs:

def deps do
  [{:logger_telegram_backend, "~> 1.3"}]
end

First of all you need to create a Telegram bot. Follow the instructions here to create one and get the token for the bot. Since bots are not allowed to contact users, you need to send a message first. Afterwards, retrieve your chat_id with $ curl -X GET https://api.telegram.org/botYOUR_TOKEN/getUpdates.

Then add LoggerTelegramBackend to the :backends configuration, configure the telegram chat_id and bot token:

config :logger, backends: [LoggerTelegramBackend, :console]

config :logger, :telegram,
  chat_id: "$chatId",
  token: "$botToken"

The logger configuration is read at runtime from the application environment so that you can provide it via distillerys dynamic configuration with environment variables.

The following options are available:

• :level - the level to be logged by this backend (either :debug, :info, :warn or :error). Note that messages are filtered by the general :level configuration for the :logger application first. If not explicitly configured all levels are logged.
• :metadata - the metadata to be included in the telegram message. Defaults to [:line, :function, :module, :application, :file]. Setting :metadata to :all gets all metadata.
• :metadata_filter - the metadata which is required in order for a message to be logged. Example: metadata_filter: [application: :ui].
• :proxy - connect via an HTTP tunnel or a socks5 proxy (only available when using :hackney). See the hackney docs for further information.
• :http_client - explicitly select the HTTP client (either LoggerTelegramBackend.HTTPClient.Hackney or LoggerTelegramBackend.HTTPClient.Mint). Picks either of which is installed as transitive or direct dependency.

config :logger, :telegram,
  chat_id: "$chatId",
  token: "$botToken",
  level: :info,
  metadata: :all
  metadata_filter: [application: :ui]

config :logger, :telegram,
  chat_id: "$chatId",
  token: "$botToken",
  proxy: "socks5://127.0.0.1:9050"

Like the LoggerFileBackend multiple logger handlers may be configured, each with different :chat_ids, :levels etc. Each handler has to be configured as a separate logger backend:

config :logger,
  backends: [
    {LoggerTelegramBackend, :telegram_filter},
    {LoggerTelegramBackend, :telegram_level},
    :console
  ]

config :logger, :telegram_filter,
  chat_id: "$chatId",
  token: "$botToken",
  metadata_filter: [application: :ui],
  metadata: [:line, :function, :module, :pid]

config :logger, :telegram_level,
  chat_id: "$chatId",
  token: "$botToken",
  level: :warn