When using tower_error_tracker, ErrorTracker.set_context doesn't work

[brainlid]

Elixir: 1.17.2
OTP: 27

In my mix.exs file, when I have:

{:tower_email, "~> 0.5.2"},
{:tower_error_tracker, "~> 0.3.3"},

and all the config was followed, error are correctly reported through email and ErrorTracker. However, when I use ErrorTracker.set_context(%{user_id: 123}), there is zero error context coming through in ErrorTracker. It shows as {} in the ErrorTracker interface. This is when raised in a LiveView process.

When I change the config to:

{:tower_email, "~> 0.5.2"},
{:error_tracker, "~> 0.4.0"},

And I remove the TowerErrorTracker reporter config :tower, :reporters, [TowerEmail], then I get a full set of error context along with custom set_context values.

[grzuy]

Hey @brainlid,

Thanks for the report!

Indeed: #20 .

It seems this is caused mainly because of the combined effects of ErrorTracker storing the context in the process dictionary, and in tower we're spawning a new process before calling the reporter.

I'll try to figure out a way it can be reported anyway...

[grzuy]

Having tower support something like Tower.set_context so that it can be sent later to all reporters is part of the plan/roadmap FWIW.

[brainlid]

Thanks @grzuy! I suspected it might be a cross-process issue. I don't know if this helps, but I've previously copied Logger's internal metadata state (stored in the process) when crossing process boundaries so things like the a Plug assigned request_id could flow deeper into spawned workers. Perhaps something like that could help here?

[grzuy]

Yes, we would need some copying of process dictionary values most probably here.

The same will be needed, as you say, for when reporting any Logger.metadata, which we'll probably will in the future.

[grzuy]

Hi @brainlid,

Just released tower 0.7.3 with a workaround (mimiquate/tower#93) that I think will fix this if you're using bandit.

To fix it for web apps using plug_cowboy will probably need a different workaround/approach.

[grzuy]

Having tower support something like Tower.set_context so that it can be sent later to all reporters is part of the plan/roadmap FWIW.

For the record, opening issue in tower regarding the above: mimiquate/tower#94.

[brainlid]

That fixed it for me! Thanks!