Docker Doc
Cheatsheet - https://dockerlabs.collabnix.com/docker/cheatsheet/
creates the container and exit
docker create ngnix
starts the docker container
docker start <container_id/name
ctrl+c wont stop process inside container but just exit the container only
docker attach --sig-proxy=false <container_id
this is create+run >> run local image and exited if found, otherwise pull it from hub
docker run ngnix
create + run + attach + delete when process is done
docker run -it --rm imagename
running container list
docker ps
all container
docker ps -a
stop docker container
docker stop container_name
remove stopped container
docker rm container_name
list all images
docker images
must remove all running container before removing image delete an image
docker rmi ngnix
only pulls image (not run)
docker pull ngnix
run container in detach mode AND sleep for 20 second
docker run -d ngnix sleep 20
attach container in CMD
docker attach docker_id
Why -it ? if you want to provide input to the application then -i is necessary, like what is your name etc etc, and whatever you want to see from terminal of container you have to attach container’s terminal to host’s terminal that’s why -t iterative mode and run bash as first command
docker run -it ngnix bash
run BASH command on container 34egr, you can run any command as you like for ex cat /etc/release
docker exec 34egr34h34 bash
this is called TAG, specify which version you want to use
docker run redis:4.0
Docker Host in your system has one IP allocated to it, and each container that run within it has different port mapped to it, so if you want to run diff instance of webapp on a single host then you have to map like this (when you first run webapp on host, it shows which port it runs on, for below example webapp runs on 5000 and mysql runs on 3306)
docker run -p 80:5000 jaydeep/webapp
docker run -p 8000:5000 jaydeep/webapp
docker run -p 8020:5000 jaydeep/webapp
docker run -p 9000:3306 mysql
docker run -p 9030:3306 mysql(so here 3 instance of webapp and 2 instance of mysql runs on Host)
all the details(internal ip,port) of container
docker inspect container_id/name
display logs(standard out) when container runs in detach mode
docker logs container_id/name
by default mysql stores its data in /var/lib/mysql, when container stops and remove its data also losts, so to persist the data written into container, we have to map external volume(host’s volume) to the data volume that container uses
docker run -v /opt/mydatadir:/var/lib/mysql mysql
give it a particular name
docker run -d --name=redis redis
How to build image Dockerfile >>default name of the file which contains instructions, for ex
FROM Ubuntu
run apt-get update && apt-get -y install python
RUN pip install flask flask-mysql
COPY . /opt/code
ENTRYPOINT FLASK_APP=/opt/code/app.py flask run-t is for tag name we give
docker build Dockerfile -t jaydeep/my-custom-app
docker host creates custom volume “data_volume” under /var/lib/docker
docker volume create data_volume
now container’s volume is mapped to our data_volume which is persistent, this alone command can also be used as docker host will automatically mount new volume as you specify name
docker run -v data_volume:/var/lib/mysql mysql
image info that when it was created and size etc
docker history image_id
build using current folder’s dockerfile
docker build .
gives a name to the untagged previously build image
docker build . -t mywebappdocker build . -f dockerfilecustom -t mytag-f is filename
total size used by images, container and volumes
docker system df
versbose, particular size used by Images
docker system df -v
by this command only single instance of app can use host’s port, thus no need to bind it s explicitely, and can run multiple apps using diff ports obviously, by default BRIDGE network is used, others are HOST and NONE
docker run ubuntu --network=host