CheatSheetsCheatSheets

Docker Exec and Logs

Get a shell inside containers and read their logs effectively.

  • docker exec
  • docker logs
  • docker cp
  • follow logs
  • container shell

Docker Exec and Logs

Get a shell inside containers and read their logs effectively.

Commands

CommandWhat it does
docker exec -it <c> shOpen a shell in a running container
docker exec <c> envInspect a container's environment
docker logs -f --tail 100 <c>Follow the last 100 log lines
docker logs --since 10m <c>Logs from the last 10 minutes
docker cp <c>:/app/out ./outCopy files out of a container

Example

docker exec -it api sh
docker logs -f --tail 100 api
docker cp api:/app/report.json ./report.json

FAQ

sh vs bash in exec?

Alpine-based images ship only sh; debian-based images usually have bash. Try sh first.

Logs show nothing — why?

The app may log to files instead of stdout; exec in and check, or configure a json-file log driver.

Preguntas frecuentes

sh vs bash in exec?
Alpine-based images ship only sh; debian-based images usually have bash. Try sh first.
Logs show nothing — why?
The app may log to files instead of stdout; exec in and check, or configure a json-file log driver.

Docker

Docker Install and Setup
Verify the Docker engine, configure context, and check versions.
Docker Images
Pull, list, tag, inspect, and remove images confidently.
Docker Containers
Run, list, stop, and clean up containers in daily work.
Docker Run Options
The flags that matter: detach, ports, env, volumes, limits.