Where is rails log file

Blog Guest Post All Blog. Ruby on Rails , Technology. Log Rotation setup is really easy. A bunch of your operating system is already using it, we just need to plug in our configuration and we are set! I like to develop web applications using Ruby and Rails framework. Apart from that in my free time, I like to read novels. Django , Technology. Latest posts. Logger produces this output. In addition to standard output, we can find the same input in the default log file. The default name of the log file is the environment name.

The default logger is available to application code in a globally accessible instance named logger. Then start the application. What are we trying to do? What is application logging? We have a way to record information about our application to a file and to standard output, which our DevOps can redirect to where they wish with standard output.

While some of this information is available from web analytics, logs can drill down to a higher level of detail. Application logging is a critical tool for helping us locate and fix errors and for collecting information that can help us improve our applications.

They lack context, though. A log entry represents an event. Something happened to the application, and the developer thought it was interesting enough to save for later review.

The most obvious thing we might want to know about an event is when it happened. What happened to debug? We can customize our logger settings either collectively in the main application.

Here we can do things like change the logging level that gets reported, define different locations for our logs, or even write to our logs in different formats that we can define ourselves. If we wanted to prevent developer-specific log messages from filling up our logs in our production environment, we could instead set the logging level to :error.

This would show only log messages from the error level down. In other words just error and fatal messages would be reported. Outside of these environment initializer files, you can also just temporarily change the log level dynamically, anywhere in your code, like this:. This might be useful if you want to turn on a verbose-level of logging around a certain task, and then quickly turn it off again.

This allows us to fully define how our logs look, and if we wanted to, we could also add our own complex logic to determine what gets logged and how it gets logged. As you can see, even this small, simple change makes the log much more readable:. Another good use case for writing your own formatting class might be if you wanted to output the logs in JSON format so that you can integrate your logs with other systems.

Another powerful feature of Rails Logger is the ability to tag our log entries. This could really useful if your application runs across multiple subdomains for example.