Honeybadger for Elixir
Typical installation time: ~3 minutes
Hi there! You've found Honeybadger's guide to Elixir exception and error tracking. Once installed, Honeybadger will automatically report errors in your Elixir application.
Getting Started
Source Code • Hex Package • Upgrading to v0.11? See the release notes
Watch our screencast by Josh Adams of ElixirSips!
Version Requirements
- Erlang >= 21.0
- Elixir >= 1.11
- Plug >= 1.0
- Phoenix >= 1.0 (This is an optional dependency and the version requirement applies only if you are using Phoenix)
1. Install the package
Add the Honeybadger package to deps/0
in your
application's mix.exs
file and run mix do deps.get, deps.compile
defp deps do
[{:honeybadger, "~> 0.16"}]
end
2. Set your API key and environment name
By default the environment variable HONEYBADGER_API_KEY
will be used to find
your API key to the Honeybadger API. If you would like to specify your key or
any other configuration options a different way, you can do so in config.exs
:
config :honeybadger,
api_key: "Your project API key"
We also need to set the name of the environment for each environment. This
ensures that we can accurately report the environment that an error occurs in.
You can add something like the following to each of your #{env}.exs
files:
config :honeybadger,
environment_name: :dev
If environment_name
is not set we will fall back to the value of Mix.env()
.
Mix.env()
uses the atomized value of the MIX_ENV
environment variable and
defaults to :prod
when the environment variable is not set. This should be good
for most setups. If you want to have an environment_name
which is different than
the Mix.env()
, you should set environment_name
in your config.exs
files for each
environment. This ensures that we can give you accurate environment information
even during compile time. Explicitly setting the environment_name
config
takes higher precedence over the Mix.env()
value.
3. Enable error reporting
The Honeybadger package can be used as a Plug alongside your Phoenix applications, as a logger backend, or as a standalone client for sprinkling in exception notifications where they are needed.
Phoenix and Plug
The Honeybadger Plug adds a
Plug.ErrorHandler
to your pipeline. Simply use
the Honeybadger.Plug
module inside of a Plug
or Phoenix.Router and any crashes will be automatically reported to
Honeybadger. It's best to use Honeybadger.Plug
after the Router plugs so that
exceptions due to non-matching routes are not reported to Honeybadger.
Phoenix app
defmodule MyPhoenixApp.Router do
use Crywolf.Web, :router
use Honeybadger.Plug
pipeline :browser do
[...]
end
end
Plug app
defmodule MyPlugApp do
use Plug.Router
use Honeybadger.Plug
[... the rest of your plug ...]
end
Logger
Just set the use_logger
option to true
in your application's config.exs
and you're good to go! Any
SASL compliant
processes that crash will send an error report to the Honeybadger.Logger
.
After the error reaches the logger we take care of notifying Honeybadger for
you!
Manual reporting
You can manually report rescued exceptions with the Honeybadger.notify
function.
try do
File.read! "this_file_really_should_exist_dang_it.txt"
rescue
exception ->
Honeybadger.notify(exception, metadata: %{}, stacktrace: __STACKTRACE__, fingerprint: "")
end
Configuration
You can set configuration options in config.exs
. It looks like this:
config :honeybadger,
api_key: "Your project API key",
environment_name: :prod
If you'd rather read, eg., environment_name
from the OS environment, you can do like this:
config :honeybadger,
environment_name: {:system, "HONEYBADGER_ENV"},
revision: {:system, "HEROKU_SLUG_COMMIT"}
NOTE: This works only for the string options, and environment_name
.
Here are all of the options you can pass in the keyword list:
Name | Description | Default |
---|---|---|
app |
Name of your app's OTP Application as an atom | Mix.Project.config[:app] |
api_key |
Your application's Honeybadger API key | System.get_env("HONEYBADGER_API_KEY")) |
environment_name |
(required) The name of the environment your app is running in. | :prod |
exclude_errors |
Filters out errors from being sent to Honeybadger | [] |
exclude_envs |
Environments that you want to disable Honeybadger notifications | [:dev, :test] |
hostname |
Hostname of the system your application is running on | :inet.gethostname |
origin |
URL for the Honeybadger API | "https://api.honeybadger.io" |
project_root |
Directory root for where your application is running | System.cwd/0 |
revision |
The project's git revision | nil |
filter |
Module implementing Honeybadger.Filter to filter data before sending to Honeybadger.io |
Honeybadger.Filter.Default |
filter_keys |
A list of keywords (atoms) to filter. Only valid if filter is Honeybadger.Filter.Default
|
[:password, :credit_card] |
filter_args |
If true, will remove function arguments in backtraces | true |
filter_disable_url |
If true, will remove the request url | false |
filter_disable_session |
If true, will remove the request session | false |
filter_disable_params |
If true, will remove the request params | false |
fingerprint_adapter |
Implementation of FingerprintAdapter behaviour | |
notice_filter |
Module implementing Honeybadger.NoticeFilter . If nil , no filtering is done. |
Honeybadger.NoticeFilter.Default |
sasl_logging_only |
If true, will notifiy for SASL errors but not Logger calls | true |
use_logger |
Enable the Honeybadger Logger for handling errors outside of web requests | true |
ignored_domains |
Add domains to ignore Error events in Honeybadger.Logger . |
[:cowboy] |
breadcrumbs_enabled |
Enable breadcrumb event tracking | false |
ecto_repos |
Modules with implemented Ecto.Repo behaviour for tracking SQL breadcrumb events | [] |
Breadcrumbs
Breadcrumbs allow you to record events along a processes execution path. If an error is thrown, the set of breadcrumb events will be sent along with the notice. These breadcrumbs can contain useful hints while debugging.
Breadcrumbs are stored in the logger context, referenced by the calling process. If you are sending messages between processes, breadcrumbs will not transfer automatically. Since a typical system might have many processes, it is advised that you be conservative when storing breadcrumbs as each breadcrumb consumes memory.
Automatic Breadcrumbs
We leverage the telemetry
library to automatically create breadcrumbs from
specific events.
Phoenix
If you are using phoenix
(>= v1.4.7) we add a breadcrumb from the router
start event.
Ecto
We can create breadcrumbs from Ecto SQL calls if you are using ecto_sql
(>=
v3.1.0). You also must specify in the config which ecto adapters you want to
be instrumented:
config :honeybadger,
ecto_repos: [MyApp.Repo]
Filtering Sensitive Data
Before data is sent to Honeybadger, it is passed through a filter to remove sensitive fields and do other processing on the data. The default configuration is equivalent to:
config :honeybadger,
filter: Honeybadger.Filter.Default,
filter_keys: [:password, :credit_card]
This will remove any entries in the context
, session
, cgi_data
and params
that match one of the filter keys. The filter is case insensitive and matches atoms or strings.
If Honeybadger.Filter.Default
does not suit your needs, you can implement your own filter. See the Honeybadger.Filter.Mixin
module doc for details on implementing your own filter.
Filtering Arguments
Honeybadger can show arguments in the stacktrace for FunctionClauseError
exceptions. To enable argument reporting, set filter_args
to false
:
config :honeybadger, filter_args: false
Customizing Error Grouping
See the Error Monitoring Guide for more information about how honeybadger groups similar exception together. You can customize the grouping for each exception in Elixir by sending a custom fingerprint when the exception is reported.
To customize the fingerprint for all exceptions that are reported from your app, use the fingerprint_adapter
configuration option in config.ex
:
config :honeybadger, fingerprint_adapter: MyApp.CustomFingerprint
defmodule MyApp.CustomFingerprint do
@behaviour Honeybadger.FingerprintAdapter
def parse(notice) do
notice.notifier.language <> "-" <> notice.notifier.name
end
end
You can also customize the fingerprint for individual exceptions when calling Honeybadger.notify
:
Honeybadger.notify(%RuntimeError{}, fingerprint: "culprit_id-123")
Proxy Configuration
If your server needs a proxy to access Honeybadger, add the following to your config
config :honeybadger,
proxy: "url",
proxy_auth: {"username", "password"}
Public Interface
Honeybadger.notify
: Send an exception to Honeybadger.
Use the Honeybadger.notify/2
function to send exception information to the
collector API. The first parameter is the exception and the second parameter
is the context/metadata/fingerprint. There is also a Honeybadger.notify/1
which doesn't require the second parameter.
Examples:
try do
File.read! "this_file_really_should_exist_dang_it.txt"
rescue
exception ->
context = %{user_id: 5, account_name: "Foo"}
Honeybadger.notify(exception, metadata: context, stacktrace: __STACKTRACE__)
end
Honeybadger.context/1
: Set metadata to be sent if an error occurs
Honeybadger.context/1
is provided for adding extra data to the notification
that gets sent to Honeybadger. You can make use of this in places such as a Plug
in your Phoenix Router or Controller to ensure useful debugging data is sent along.
Examples:
def MyPhoenixApp.Controller
use MyPhoenixApp.Web, :controller
plug :set_honeybadger_context
def set_honeybadger_context(conn, _opts) do
user = get_user(conn)
Honeybadger.context(user_id: user.id, account: user.account.name)
conn
end
end
Honeybadger.context/1
stores the context data in the process dictionary, so
it will be sent with errors/notifications on the same process. The following
Honeybadger.notify/1
call will not see the context data set in the previous line.
Honeybadger.context(user_id: 5)
Task.start(fn ->
# this notify does not see the context set earlier
# as this runs in a different elixir/erlang process.
Honeybadger.notify(%RuntimeError{message: "critical error"})
end)
Honeybadger.add_breadcrumb/2
: Store breadcrumb within process
Appends a breadcrumb to the notice. Use this when you want to add some custom data to your breadcrumb trace in effort to help debugging. If a notice is reported to Honeybadger, all breadcrumbs within the execution path will be appended to the notice. You will be able to view the breadcrumb trace in the Honeybadger interface to see what events led up to the notice.
Examples:
Honeybadger.add_breadcrumb("Email sent", metadata: %{
user: user.id,
message: message
})
Honeybadger.event
: Send an event to Honeybadger Insights.
Use the Honeybadger.event/1
function to send event data to the events API. A
ts
field with the current timestamp will be added to the data if it isn't
provided. You can also use Honeybadger.event/2
, which accepts a string as the
first parameter and adds that value to the event_type
field in the map before
being sent to the API.
Examples:
Honeybadger.event(%{
event_type: "user_created",
user: user.id
})
Honeybadger.event("project_deleted", %{
project: project.name
})
Excluded Environments
Honeybadger won't report errors from :dev
and :test
environments by default. To enable error reporting in dev:
- Set the HONEYBADGER_API_KEY as documented above
- Remove
:dev
from theexclude_envs
by adding this to your config/dev.exselixir config :honeybadger, exclude_envs: [:test]
- Run the
mix honeybadger.test
mix task task to simulate an error
Sample Application
If you'd like to see the module in action before you integrate it with your apps, check out our sample Phoenix application.
You can deploy the sample app to your Heroku account by clicking this button:
Don't forget to destroy the Heroku app after you're done so that you aren't charged for usage.
The code for the sample app is available on Github, in case you'd like to read through it, or run it locally.