BoomNotifier
This package allows your Phoenix application to send notifications whenever an exceptions is raised. By default it includes an email and a webhook notifier, but you can implement your custom ones.
It was inspired by the ExceptionNotification gem that provides a similar functionality for Rack/Rails applications.
You can read the full documentation at https://hexdocs.pm/boom_notifier.
Installation
The package can be installed by adding boom_notifier
to your list of dependencies in
mix.exs
:
def deps do
[
{:boom_notifier, "~> 0.5.0"}
]
end
How to use it
Webhook notifier
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notifier: BoomNotifier.WebhookNotifier,
options: [
url: "http://example.com",
headers: [Authorization: "Bearer token"]
]
# ...
To configure it, you need to set the url
in the options
keyword list. A POST
request with a json
will be made to that webhook when an error ocurrs with the relevant information.
Optionally, you could also add headers
to the request as another keyword list.
Email notifier
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notifier: BoomNotifier.MailNotifier,
options: [
mailer: YourApp.Mailer,
from: "me@example.com",
to: "foo@example.com",
subject: "BOOM error caught"
]
# ...
For the email to be sent, you need to define a valid mailer in the options
keyword list. You can customize the from
, to
and subject
attributes.
Custom notifiers
To create a custom notifier, you need to implement the BoomNotifier.Notifier
behaviour:
@callback notify(list(%ErrorInfo{}), keyword(String.t())) :: no_return()
defmodule CustomNotifier do
@behaviour BoomNotifier.Notifier
@impl BoomNotifier.Notifier
def notify(errors, options) do
# ...
# ...
# ...
end
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notifier: CustomNotifier,
options: [
# ...
]
You can also implement an optional callback validate_config
that receives
the options
keyword list set in the notifier so the user can be warned
during compilation if the attributes are not correct.
@callback validate_config(keyword(String.t())) :: :ok | {:error, String.t()}
Multiple notifiers
BoomNotifier also supports a list of multiple notifiers like in the example below:
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notifiers: [
[
notifier: BoomNotifier.WebhookNotifier,
options: [
url: "http://example.com",
]
],
[
notifier: CustomNotifier,
options: # ...
]
]
Notification Trigger
By default, BoomNotifier
will send a notification every time an exception is
raised.
However, there are different strategies to decide when to send the
notifications using the :notification_trigger
option with one of the
following values: :always
and :exponential
.
Always
This option is the default one. It will trigger a notification for every exception.
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notification_trigger: :always,
notifiers: [
# ...
]
Exponential
It uses a formula of log2(errors_count)
to determine whether to send a
notification, based on the accumulated error count for each specific
exception. This makes the notifier only send a notification when the count
is: 1, 2, 4, 8, 16, 32, 64, 128, ..., (2**n).
You can also set an optional max value.
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notification_trigger: :exponential,
notifiers: [
# ...
]
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
notification_trigger: [exponential: [limit: 100]]
notifiers: [
# ...
]
Custom data or Metadata
By default, BoomNotifier
will not include any custom data from your
requests.
However, there are different strategies to decide which information do
you want to include in the notifications using the :custom_data
option
with one of the following values: :assigns
, :logger
or both.
The included information will show up in your notification, in a new section titled "Metadata".
Assigns
This option will include the data that is in the connection
assigns
field.
You can also specify the fields you want to retrieve from conn.assigns
.
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
custom_data: :assigns,
notifiers: [
# ...
]
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
custom_data: [assigns: [fields: [:current_user, :session_data]]],
notifiers: [
# ...
]
Example of adding custom data to the connection:
assign(conn, :name, "John")
Logger
This option will include the data that is in the Logger
metadata
field.
You can also specify the fields you want to retrieve from Logger.metadata()
.
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
custom_data: :logger,
notifiers: [
# ...
]
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
custom_data: [logger: [fields: [:request_id, :current_user]]],
notifiers: [
# ...
]
Example of adding custom data to the logger:
Logger.metadata(name: "John")
Using both
You can do any combination of the above settings to include data from both sources. The names of the fields are independent for each source, they will appear under the source namespace.
defmodule YourApp.Router do
use Phoenix.Router
use BoomNotifier,
custom_data: [
[assigns: [fields: [:current_user]]],
[logger: [fields: [:request_id, :current_user]]]
],
notifiers: [
# ...
]
License
BoomNotifier is released under the terms of the MIT License.
Credits
The authors of this project are Ignacio and Jorge. It is sponsored and maintained by Wyeworks.