Feature: Make LOG_LEVEL configurable

[luckyAkbar]

Summary

This PR introduces configurable logging levels to enhance flexibility and reduce unnecessary log output in production environments. The default log level remains INFO, ensuring backward compatibility.

Background

While running fusion in a Docker container, I observed excessive log growth due to the default INFO logging level. This can lead to storage concerns in long-running production deployments where verbose logs are unnecessary. Currently, the application does not support log level configuration, limiting users' ability to control log output.

Changes

• Added support for the LOG_LEVEL environment variable
• Maintained INFO as the default level when:
  • LOG_LEVEL is unset
  • An invalid value is provided
• Implemented support for these valid log levels:
  • DEBUG
  • INFO
  • WARN (or WARNING)
  • ERROR

Configuration

The log level can be configured through:

1. Environment variables file
2. Docker environment variables (-e flag)

Example Docker command:

docker run --rm -it -d -p 9080:8080 -e PASSWORD="fusion" -e LOG_LEVEL=ERROR your_image_id

Example (Before implementing configurable log level)

this is the sample of my container's log after running the app for the first time, log in and then refreshing the feed several times

docker logs -f 5b879037a436
{"time":"2025-09-20T15:32:22.21879047Z","level":"WARN","msg":"no configuration file found at .env"}
⇨ http server started on [::]:8080
{"time":"2025-09-20T15:32:45.445553301Z","level":"ERROR","msg":"code=401, message=Unauthorized","uri":"/api/groups","status":401}
{"time":"2025-09-20T15:32:45.447826329Z","level":"ERROR","msg":"code=401, message=Unauthorized","uri":"/api/feeds","status":401}
{"time":"2025-09-20T15:32:45.451687128Z","level":"ERROR","msg":"code=401, message=Unauthorized","uri":"/api/items?page=1&page_size=12&unread=true","status":401}
{"time":"2025-09-20T15:32:49.326484802Z","level":"ERROR","msg":"code=400, message=Password is a required field.","uri":"/api/sessions","status":400}
{"time":"2025-09-20T15:32:52.736130333Z","level":"ERROR","msg":"code=401, message=Wrong password","uri":"/api/sessions","status":401}
{"time":"2025-09-20T15:33:02.16680381Z","level":"INFO","msg":"REQUEST","uri":"/api/sessions","status":201}
{"time":"2025-09-20T15:33:02.182048779Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:02.187393763Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:02.192042578Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:23.868491987Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:23.874223724Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:23.87660873Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:26.176484064Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:26.179167408Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:26.179401996Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:26.297843776Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:26.299729473Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:26.302641935Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:26.536957401Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:26.541698533Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:26.541884687Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:26.72061006Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:26.723198152Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:26.725941943Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:26.861880937Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:26.86318292Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:26.863403438Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:27.001681713Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:27.002875484Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:27.003817493Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:27.131038896Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:27.13325928Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}
{"time":"2025-09-20T15:33:27.134464665Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:27.266195309Z","level":"INFO","msg":"REQUEST","uri":"/api/groups","status":200}
{"time":"2025-09-20T15:33:27.269629643Z","level":"INFO","msg":"REQUEST","uri":"/api/feeds","status":200}
{"time":"2025-09-20T15:33:27.270089514Z","level":"INFO","msg":"REQUEST","uri":"/api/items?page=1&page_size=12&unread=true","status":200}

Example (After implementing configurable log level)

After the feature has been made, I run the app using docker and set the LOG_LEVEL value using this command: docker run --rm -it -d -p 9080:8080 -e PASSWORD="fusion" -e LOG_LEVEL=ERROR aac4f28d8385, log in and then refresh the feed several times. Below are the output log on my container

docker logs -f a3800b40f095
{"time":"2025-09-20T15:35:10.827919642Z","level":"WARN","msg":"no configuration file found at .env"}
⇨ http server started on [::]:8080
{"time":"2025-09-20T15:35:57.027358891Z","level":"ERROR","msg":"code=401, message=Unauthorized","uri":"/api/groups","status":401}
{"time":"2025-09-20T15:35:57.030445275Z","level":"ERROR","msg":"code=401, message=Unauthorized","uri":"/api/feeds","status":401}
{"time":"2025-09-20T15:35:57.030515984Z","level":"ERROR","msg":"code=401, message=Unauthorized","uri":"/api/items?page=1&page_size=12&unread=true","status":401}

Any feedback to better improve this PR is appreciated