View Source PhoenixProfiler (phoenix_profiler v0.1.0)

Provides a development tool that gives detailed information about the execution of any request.

Never enable it on production servers as it exposes sensitive data about your web application.

Built-in Features

Request/Response - status code, params, headers, cookies, etc.
Routing - endpoint, router, controller/live view, action, etc.
Basic diagnostics - response time, memory
Inspect LiveView crashes
Inspect Ecto queries (Coming Soon)
Swoosh mailer integration (Coming Soon)

Installation

To start using the profiler, you will need the following steps:

Add the phoenix_profiler dependency
Define a profiler on your supervision tree
Enable the profiler on your Endpoint
Configure LiveView
Add the PhoenixProfiler plug
Mount the profiler on your LiveViews
Add the profiler page on your LiveDashboard (optional)

1. Add the phoenix_profiler dependency

Add phoenix_profiler to your mix.exs:

{:phoenix_profiler, "~> 0.1.0"}

2. Define a profiler on your supervision tree

You define a profiler on your main application's telemetry supervision tree (usually in lib/my_app_web/telemetry.ex):

    children = [
      {PhoenixProfiler, name: MyAppWeb.Profiler},
      # :telemetry_poller, etc.
    ]

Note that the profiler must be running for data to be collected, so it must come before any Endpoint modules in your supervision tree.

The following options are available:

:name - The name of the profiler server. This option is required.
:request_sweep_interval - How often to sweep the ETS table where the profiles are stored. Default is 24h in milliseconds.

3. Enable the profiler on your Endpoint

PhoenixProfiler is disabled by default. In order to enable it, you must update your endpoint's :dev configuration to include the :phoenix_profiler options:

# config/dev.exs
config :my_app, MyAppWeb.Endpoint,
  phoenix_profiler: [server: MyAppWeb.Profiler]

All web configuration is done inside the :phoenix_profiler key on the endpoint.

The following options are available:

:server - The name of the profiler server. This option is required.
:enable - When set to false, disables profiling by default. You can always enable profiling on a request via enable/1. Defaults to true.
:profiler_link_base - The base path for generating links on the toolbar. Defaults to "/dashboard/_profiler".
:toolbar_attrs - HTML attributes to be given to the element injected for the toolbar. Expects a keyword list of atom keys and string values. Defaults to [].

4. Configure LiveView

If LiveView is already installed in your app, you may skip this section.

The Phoenix Web Debug Toolbar is built on top of LiveView. If you plan to use LiveView in your application in the future we recommend you follow the official installation instructions. This guide only covers the minimum steps necessary for the toolbar itself to run.

Update your endpoint's configuration to include a signing salt. You can generate a signing salt by running mix phx.gen.secret 32 (note Phoenix v1.5+ apps already have this configuration):

# config/config.exs
config :my_app, MyAppWeb.Endpoint,
  live_view: [signing_salt: "SECRET_SALT"]

5. Add the PhoenixProfiler plug

Add the PhoenixProfiler plug within the code_reloading? block on your Endpoint (usually in lib/my_app_web/endpoint.ex):

  if code_reloading? do
    # plugs...
    plug PhoenixProfiler
  end

6. Mount the profiler on your LiveViews

Note this section is required only if you are using LiveView, otherwise you may skip it.

Add the profiler hook to the live_view function on your web module (usually in lib/my_app_web.ex):

  def live_view do
    quote do
      # use...

      on_mount PhoenixProfiler

      # view helpers...
    end
  end

Note the on_mount macro requires LiveView 0.16+. For earlier versions, see PhoenixProfiler.enable/1.

This is all. Run mix phx.server and observe the toolbar on your browser requests.

7. Add the profiler page on your LiveDashboard (optional)

Note this section is required for the LiveDashboard integration. If you are not using LiveDashboard, you may technically skip this step, although it is highly recommended that you install LiveDashboard to enjoy all the features of PhoenixProfiler.

Add the dashboard definition to the list of :additional_pages on the live_dashboard macro in your router (usually in lib/my_app_web/router.ex):

live_dashboard "/dashboard",
  additional_pages: [
    _profiler: {PhoenixProfiler.Dashboard, []}
    # additional pages...
  ]

Link to this section Summary

Functions

all_running()

Returns all running PhoenixProfiler names. It is important to notice that no order is guaranteed.

child_spec(opts)

Returns the child specification to start the profiler under a supervision tree.

disable(conn_or_socket)

Disables profiling on a given conn or socket.

enable(conn_or_socket)

Enables the profiler on a given conn or connected socket.

on_mount(arg, params, session, socket)

The callback for the mount stage of the LiveView lifecycle.

reset(profiler)

Resets the storage of the given profiler.

Link to this section Functions

all_running()

Returns all running PhoenixProfiler names. It is important to notice that no order is guaranteed.

child_spec(opts)

Returns the child specification to start the profiler under a supervision tree.

disable(conn_or_socket)

Disables profiling on a given conn or socket.

Examples

Within a Phoenix Controller (for example, on an update callback):

def update(conn, params) do
  conn = PhoenixProfiler.disable(conn)
  # code...
end

Within in a LiveView (for example, on a handle_event callback):

def handle_event("some-event", _, socket) do
  socket = PhoenixProfiler.disable(socket)
  # code...
end

Note that only for LiveView, if you invoke disable/1 on the LiveView mount callback, the profiler may not be registered yet and it will not receive the disable message. If you need on-demand profiling, it is recommended you start with the profiler in a disabled state and enable it after the LiveView has mounted.

enable(conn_or_socket)

Enables the profiler on a given conn or connected socket.

Normally you do not need to invoke this function manually. It is invoked automatically by the PhoenixProfiler plug in the Endpoint when a profiler is enabled. In LiveView v0.16+ it is invoked automatically when you define on_mount PhoenixProfiler on your LiveView.

This function will raise if the endpoint is not configured with a profiler, or if the configured profiler is not running. For LiveView specifically, this function also raises if the given socket is not connected.

Example

Within a Phoenix Controller (for example, on a show callback):

def show(conn, params) do
  conn = PhoenixProfiler.enable(conn)
  # code...
end

Within a LiveView (for example, on the mount callback):

def mount(params, session, socket) do
  socket =
    if connected?(socket) do
      PhoenixProfiler.enable(socket)
    else
      socket
    end

  # code...
end

on_mount(arg, params, session, socket)

The callback for the mount stage of the LiveView lifecycle.

To enable live profiling, add the following on your LiveView:

on_mount PhoenixProfiler

reset(profiler)

Resets the storage of the given profiler.

Settings View Source PhoenixProfiler (phoenix_profiler v0.1.0)

Built-in Features

Installation

1. Add the phoenix_profiler dependency

2. Define a profiler on your supervision tree

3. Enable the profiler on your Endpoint

4. Configure LiveView

5. Add the PhoenixProfiler plug

6. Mount the profiler on your LiveViews

7. Add the profiler page on your LiveDashboard (optional)

Link to this section Summary

Functions

Link to this section Functions

all_running()

child_spec(opts)

disable(conn_or_socket)

Examples

enable(conn_or_socket)

Example

on_mount(arg, params, session, socket)

reset(profiler)

View Source PhoenixProfiler (phoenix_profiler v0.1.0)