krishna_vaguelyright
How to handle errors centrally?
In my local instance, it throws the error with proper error codes. On prod deployed to fly, it just throws a 500 status error.
In my tests I have to use assert_error_sent to make tests pass. When i try to assert conn.status it just throws an error in test module.
conn = post(conn, `route`, %{})
assert conn.status == 400
This is what my code looks like… works fine in dev locally but throws 500 error in prod.
defmodule KayaanPrintsWeb.Router do
use KayaanPrintsWeb, :router
use Plug.ErrorHandler
require Logger
@impl true
def handle_errors(conn, %{kind: kind, reason: reason, stack: stack}) do
error_string = log_error_string(kind, reason, stack, conn)
case reason do
%Phoenix.Router.NoRouteError{} ->
Logger.error(error_string)
conn
|> put_status(:not_found)
|> json(%{error: "Route not found"})
|> halt()
....other error cases handling
Where Next?
Trending in Questions
Other Trending Topics
Latest on Elixir Forum
Sponsor Spotlight
Catch errors, track performance, monitor hosts and more.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #library
- #deployment
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #elixirconf
- #channels
- #exunit
- #discussion
- #code-sync
- #podcasts
- #javascript
- #onsite
- #dialyzer
- #docker
- #authentication
- #ai
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #blog-post
- #elixirconf-us
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #elixirconf-eu
- #api
- #forms
- #security
- #performance
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Error tracking, logs, uptime, and Just Enough APM. Built for developers.
Elixir, Erlang & BEAM conferences from Code Sync - join us in 2026!
Master modern tools, write cleaner code, and tackle real-world challenges.
Bringing learning, work and compliance together since 1987.
**Building the future of software with AI, trust, and human connection.**
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
Showing Posts 1 to 4- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
D4no0
Phoenix is configured so that in
prodconfiguration no errors are shown in the response, you wouldn’t want someone getting logs from your application when something goes wrong for a deployed instance. That obviously can be changed from configuration, look what config phoenix is using for logging indev.exsand update it inprod.exsorruntime.exs.Errors with code status
500are always related to server errors, this means something unexpected went wrong on the server. In this case, this error is returned because the process serving the request crashed. This functionality should not be tested, as this is considered a bug that should be fixed.For errors that come from controllers, I strongly recommend using action_fallback/1 instead of mechanism of catching errors.
LostKobrakai
If your test fails your code has a problem.
This likely works in dev, because phoenix enables
Plug.Debuggerin development. There can only ever be one error handler though, so yourPlug.ErrorHandlermight not even run.krishna_vaguelyright
I am also trying to setup telemetry, error-logging in my app.
Could you possibly direct me to some good resources around this. I am new to Elixir/Phoenix & getting a bit confused around setting things up properly. I am reading Elixir-In-Action & Phoenix-In-Action books on the side to understand the ecosystem better but need to ship too.
For observability & monitoring (esp Sentry for now) I found the below resources. Would love to have something which is more comprehensive & which explains the internals also… Also something around monitoring sockets, channels would be great.
Thanks!
krishna_vaguelyright
Trying to bump this up…