ex_debug_toolbar

A debug web toolbar for Phoenix projects to display all sorts of information about request

Monthly Downloads: 260

Programming language: Elixir

License: Apache License 2.0

Tags: Debugging    

Latest version: v0.5.0

README

A toolbar for Phoenix projects to display all sorts of information about current and previous requests: logs, timelines, database queries etc.

Project is in its early stages and under active development. Contributions to code, feedback and suggestions will be much appreciated!

[Screencapture](screenshots/toolbar.gif)

Recent changes

### Version 0.5.0

• (new) phoenix 1.3
• (new) support bootstrap 4 ### Version 0.4.0
• (new) requests history panel
• (new) support Slim templates (phoenix_slim package)
• (new) debug config key to enable to verbose logs
• (new) ignore_paths config key to skip tracking certain requests by paths
• (improved) breakpoints no longer use distribution code

Features

Toolbar is built with development environment in mind. It's up to you to enable or disable it in configuration. Calls to toolbar functions such as Toolbar.pry are no-op when it is disabled.

After enabling the toolbar, it automatically injects itself at the bottom of html pages. Some panels on the toolbar are optional and only appear when relevant data is available (ecto queries, for example). [Toolbar](screenshots/toolbar.png)

Let's take a look at available panels:

Timings

It shows overall time spent rendering current controller as reported by Phoenix instrumentation. In addition, it provides aggregated stats for each template. [Timings](screenshots/timings.png)

History

A list of previous request. [History](screenshots/history.png) Clicking on historical request loads it into toolbar so you can inspect it closer. [History Loaded](screenshots/history_loaded.png)

Connection details

Surfaces information from conn struct of current request. [Connection Details](screenshots/conn_details.png)

Logs

Log entries relevant to current request only [Logs](screenshots/logs.png)

Ecto queries

A list of executed ecto queries including parallel preloads when possible. [Ecto Queries](screenshots/ecto_queries.png)

Breakpoints

Think of having multiply IEx.pry breakpoints available on demand right from the toolbar. Note, unlike IEx.pry, this does not interfere with execution flow of phoenix server.

Usage is similar to IEx. Drop require ExDebugToolbar; ExDebugToolbar.pry in a file you'd like to debug and breakpoint will appear in this panel. Breakpoints are capped at configurable number per request (10 by default). [Breakpoints](screenshots/breakpoints.png)

A click on any breakpoint will take you to familiar iex session with context as it was at execution time. [Breakpoint Sesssion](screenshots/breakpoint_session.png)

Installation

1. Add ex_debug_toolbar to your list of dependencies in mix.exs:

   def deps do
     [{:ex_debug_toolbar, "~> 0.4.0"}]
   end

1. Ensure :ex_debug_toolbar is started before your application:

   def application do
     [applications: [:ex_debug_toolbar, :logger]]
   end

1. Add ExDebugToolbar.Phoenix to your endpoint in lib/my_app/endpoint.ex

    defmodule MyApp.Endpoint do
      use Phoenix.Endpoint, otp_app: :my_app
      use ExDebugToolbar.Phoenix
      ...
    end

1. Enable toolbar in config config/dev.exs and setup collectors. Replace :my_app and MyApp with your application name

   Note: Slim templates support requires phoenix_slime package

    # ExDebugToolbar config
    config :ex_debug_toolbar,
      enable: true

    config :my_app, MyApp.Endpoint,
      instrumenters: [ExDebugToolbar.Collector.InstrumentationCollector]

    config :my_app, MyApp.Repo,
      loggers: [ExDebugToolbar.Collector.EctoCollector, Ecto.LogEntry]

    config :phoenix, :template_engines,
      eex: ExDebugToolbar.Template.EExEngine,
      exs: ExDebugToolbar.Template.ExsEngine,
      #slim: ExDebugToolbar.Template.SlimEngine,
      #slime: ExDebugToolbar.Template.SlimEngine

1. To display parallel Ecto preloads you have to use master branch elixir defp deps do [ {:ecto, github: "elixir-ecto/ecto", branch: "master", override: true} ] end

Configuration

To change configuration, update :ex_debug_toolbar config key in your config/dev.exs. For example:

    config :ex_debug_toolbar,
      enable: true

Available options:

Option	Values	Default	Description
enable	boolean	false	Enable/disable toolbar. When disabled, toolbar code is not injected in page and toolbar functions are mostly no-op.
iex_shell	string	"/bin/sh"	Shell executable to be used for breakpoint session
iex_shell_cmd	string	"stty echo; clear; iex -S mix breakpoint.client --breakpoint-file %{breakpoint_file}"	Shell command to launch breakpoint iex session. %{breakpoint_file} is a placeholder for tmp file with data
breakpoints_limit	integer	10	Maximum number of breakpoints per request. After reaching this cap, new breakpoints will be ignored
remove_glob_params	boolean	true	Plug.Router adds glob params to conn.params and conn.path_params on forward. This option removes them
ignore_paths	list	[~r{/images/}, ~r{/css/}, ~r{/js/}, ~r{/phoenix/live_reload/}]	A list of paths that should not be recorded by toolbar. Each item can be either string for exact match or a Regex.
debug	boolean	false	Toggles debug logs. Requires recompilation for some logs

Troubleshooting

Poison encode issues

If you see poison encode related errors in your logs:

• update to latest poison package version
• enable debug mode and open an issue with detailed logs

Debug mode

When enabled, toolbar prints debug logs. This information is very helpful for issues with encoding, missing requests, etc.

Turn on debug mode

    config :ex_debug_toolbar,
      enable: true,
      debug: true

Turn off Logger log truncation and put it into debug level

    config :logger,
      level: :debug,
      truncate: :infinity

Recompile toolbar to see channel logs

    mix deps.compile ex_debug_toolbar --force

Contributors

Special thanks goes to Juan Peri!

Contribution

Contributions in the form of bug reports, pull requests, or thoughtful discussions in the GitHub issue tracker are welcome!

TODO

• [ ] Toolbar panels
  • [ ] Messages output panel (Toolbar.inspect and Toolbar.puts)
  • [ ] System info panel (versions, vm info, etc)
  • [ ] Help/Docs Panel (links to dev resources)
  • [ ] Request time panel
  • [ ] Request history (historical graphs?)
  • [ ] Visualize timeline
  • [ ] Ajax requests panel
  • [ ] Channels info panel
  • [ ] Visualize gettext
• [ ] Toolbar API
  • [ ] Decorator for functions to time them
  • [ ] Add metadata to events and use groupable names (template.render, controller.render etc)
• [ ] Tests
  • [ ] breakpoints
  • [ ] client test
  • [ ] terminal test
• [ ] Simple installer mix task
• [ ] Upgrade to Phoenix 1.3
• [ ] Elm/React instead of jquery?

Demo App

Use demo app to simplify development process.