Simple logging in .NET Core app on Elastic Beanstalk

Question

I'm just starting to put some ASP.NET Core apps on Elastic Beanstalk. I want to do some simple logging initially just to track down some issues. I normally use Serilog, but at this point, I just need to get some info out to a log that I can view.

I see that it captures exceptions in /var/log/web.stdout.log (running on Linux).

Can I just have Serilog's File sink write to one of these files?

I will eventually implement Cloudwatch, but right now I'm looking for something simple.

Answer 1

You can't write direct into /var/log/web.stdout.log as the file is owned by root, and your app executes under webapp user. You will get access denied if you try to modify the log file directly.

But you can tell EB which log files, specific to your application, to include in its bundles. This is done through .ebextensions. Specifically, you can have a config file .ebextensions/mylogfiles.config with the exemplary content of:

files: 
  "/opt/elasticbeanstalk/config/private/logtasks/bundle/mylogfiles.conf":
    mode: "000644"
    owner: root
    group: root
    content: |
       /var/app/current/logs/*.log

where /var/app/current/log/*.log would need to be adjusted to how your application store its logs.