Logs, inspect & lifecycle
Read logs before restarting
Lesson 3 of 20 · 12 min · Module 1: Containers and access
Gather evidence before replacing the thing you are trying to diagnose.
Start this lesson →Free. No installation: you write and run the code in your browser, and it is checked automatically.
By the end, you’ll be able to…
- Collect application evidence
- Inspect the configuration
The idea
Container operations change instances and their attached configuration. Inspect the resulting state as well as the command sequence.
01Collect application evidence
docker logs reads output recorded by the container process. In this model it includes a sample listening message and a health request. A restart alone does not explain a failure.
02Inspect the configuration
docker inspect gives metadata such as image, ports, and mounts. Use it to check whether the process was configured the way you expected.
03Distinguish stop from removal
stop changes the lifecycle state. rm removes the container record after it has stopped. Keeping it briefly can preserve useful diagnostic evidence.
Your turn
What the checks look for
- Reads logs and configuration
- Stops without removing the container
Take this with you
Observe, form a hypothesis, and then change the system.
Go a little further
Start the stopped container again and compare its image and name.