Commands
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| # pull images
$ docker pull busybox
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| # run an image/ finds no command / gets exited
$ docker run busybox
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| # containers are fast / getting into vm doing this and exiting (slow)
$ docker run busybox echo "hello from busybox"
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| # all containers that are running
$ docker ps
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| # all containers that ran
$ docker ps -a
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| # attaches the interavtive shell
$ docker run -it busybox sh
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| # removes the container when it exits
$ docker run --rm prakhar1989/static-site
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--rm flag automatically removes the container when it exits
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| $ docker run -d -P --name static-site prakhar1989/static-site
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- keep the container running providing name to it
-d will detach the terminal -P publish the ports --name desired name for the container
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| # ports
$ docker port [CONTAINER --name]
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- see the ports [ only after publishing the ports with
-P]
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| # copy from container
$ docker cp <containerId>:/file/path/within/container /host/path/target
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- copy from docker container
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| # stop container
$ docker stop static-site
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Somehow messed up and start from scratch?
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| # remove all docker containers
$ docker rm $(docker ps -a -q) -f
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- remove all docker containers
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| # remove all docker images
$ docker rmi $(docker images) -f
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Some Docker Terminologies
images
- docker pull command to download the busybox image
containers
- created from docker images and run the actual application
docker daemon
- background service running on the host(locally your pc or anything that the docker is running) that manages building, running and distributing docker containers.
docker client
- cli tool that allows (me) to interact with the daemon
- GUI clients - Kitematic
docker hub
- a registry of docker images / directory of all the available docker images
Docker Images
- basis of containers
$ docker images to view images locally$ docker search python to search for images- images (like git repos)
- can have multuple versions
- if not provided picks latest version
$ docker pull ubuntu:18.04
Docker Expose
Docker Compose cheatsheet
https://devhints.io/docker-compose
- remove docker containers (not active)
$ docker rm (docker ps -a -q) -f
- remove hanging images
$ docker rmi (docker images -f dangling=true -q)
- docker compose up –build again
$ docker-compose up --build again
- remove all the images from repository name
docker rmi $(docker images -q ubuntu)
Thrive to minimize image size
Docker multi-stage build
https://docs.docker.com/develop/develop-images/multistage-build/
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| # single docker file could be used for multiple stage builds...
# for example:
FROM python:3.6-alpine as dev-build
# -
# -
# -
# -
# -
# --------
FROM python:3.6-alpine as prod-build
# this app includes the dist and all the necessary build files (in case of js)
COPY --from=dev-build /app/ .
# -
# -
# -
# -
# -
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Stopping at a specific build stage
It’s not necessary for Dockerfile to run all at once…
$ docker build --target dev-build -t sisir/django-app:latest .
Use a previous stage as a new stage
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| FROM alpine:latest as builder
RUN apk --no-cache add build-base
FROM builder as build1
COPY source1.cpp source.cpp
RUN g++ -o /binary source.cpp
FROM builder as build2
COPY source2.cpp source.cpp
RUN g++ -o /binary source.cpp
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- Docker compose allows to configure multi-container app.
Container Vs. Entrypoint
https://phoenixnap.com/kb/docker-cmd-vs-entrypoint
