Docker Commands

Find Docker Usage

docker system df

docker system prune -a --volumes

‼️ WARNING! This will remove:

• all stopped containers
• all networks not used by at least one container
• all volumes not used by at least one container
• all images without at least one container associated to them
• all build cache

Build image

docker build -t frontend --build-arg NPM_AUTH_TOKEN=TOKEN .

Download newer image

docker pull <image name>

Display all running containers

docker ps -a

check running containers

docker ps

dive into docker container

docker exec -it dreamy_nash /bin/bash
docker exec -it 1d3912322644 /bin/bash

How to clean your Docker data

Cleaning Up Your Docker Environment

#!/bin/bash
# Delete all containers
docker rm $(docker ps -a -q)
# Delete all images
docker rmi $(docker images -q)

# Kill a particular container.
docker kill [container]

• docker kill \$(docker ps -q): Kill all containers that are currently running.
• docker rm [container]: Delete a particular container that is not currently running.
• docker rm \$(docker ps -a -q): Delete all containers that are not currently running.
• docker rmi \$(docker images -a -q): Delete all images

To start a shell in a container:

docker exec -ti \$(CONTAINER) /bin/bash

exec run a command in a running container Exec -interactive Keep STDIN open even if not attached Exec -t: tty allocate a pseudo TTY not genuine but having the appearance of

ADD vs COPY Although ADD and COPY are functionally similar, generally speaking, COPY is preferred. That’s because it’s more transparent than ADD. COPY only supports that basic copying of local files into the container, while ADD has some features ( like local-only tar extraction and remote URL support) that are not immediately obvious.

If you have multiple Dockerfile steps that use different files from your context, COPY them individually, rather than all at once. This ensures that each step’s build cache is only invalidated (forcing the step to be re-run) if the specifically required files change. For example:

COPY requirements.txt /tmp/
RUN pip install --requirement /tmp/requirements.txt
COPY . /tmp/

Results in fewer cache invalidations for the RUN step, than if you put the COPY . /tmp/ before it. Because image size matters, using ADD to fetch packages from remote URLs is strongly discouraged; you should use curl or wgetinstead. That way you can delete the files you no longer need after they’ve been extracted and you don’t have to add another layer in your image. For example, you should avoid doing things like:

ADD http://example.com/big.tar.xz /usr/src/things/
RUN tar -xJf /usr/src/things/big.tar.xz -C /usr/src/things
RUN make -C /usr/src/things all
And instead, do something like:
RUN mkdir -p /usr/src/things \
 && curl -SL http://example.com/big.tar.xz \
 | tar -xJC /usr/src/things \
 && make -C /usr/src/things all