Docker cheatsheet

Logs in time window

docker logs postgres -t --since 2018-11-29T12:21:00 --until 2018-11-29T12:22:00 2>&1 >/dev/null | grep -n "phrase"

List Docker registry

curlie http://localhost:5000/v2/_catalog
curlie http://localhost:5000/v2/my-name/postgres/tags/list
curlie http://localhost:5000/v2/my-name/postgres/manifests/latest

Remove image from Docker registry

curlie -X DELETE http://localhost:5000/v2/my-name/postgres/manifests/latest

if --env=REGISTRY_STORAGE_DELETE_ENABLED=true

Clear Docker local registry, containers & images

sudo docker rm -f `sudo docker ps -a -q`
sudo docker rmi -f `sudo docker images -q`

runlike: check docker run command

pip install runlike
runlike postgres

Enter shell on exited container

CONTAINER=postgres
docker rmi -f tmp
docker commit $CONTAINER tmp
docker run -it --rm --entrypoint=bash tmp

Declutter disk usage

docker image prune
docker system prune -a --volumes
docker system df

History of commands (layers)

docker history postgres:10

Explore image layers

docker run --rm -it \
    -v /var/run/docker.sock:/var/run/docker.sock \
    wagoodman/dive:latest \
    postgres:10

Manage docker resources

docker run --rm -it -p 8001:8000 -p 9001:9000 --name=portainer -v /var/run/docker.sock:/var/run/docker.sock portainer/portainer-ce
localhost:9001

Am I in Docker?

cat /proc/1/cgroup
# root paths or /docker/...

Gain root access with docker

docker run -it --rm -v `pwd`:`pwd` -w `pwd` ubuntu bash

Update docker container restart policy

docker update --restart=unless-stopped reverseproxy

Attach to stdin (debugger)

Attach to stdin of a -it container:

docker attach CONTAINER
detach with sequence: Ctrl^P, Ctrl^Q