Docker

Docker

Docker

To run an existing or non-existing image
docker run ubuntu
It means to run a container with this image on it

To pull/download an image from docker hub registry

docker pull busybox
docker run busybox

Docker images
docker images

Remove docker image

docker image rm imageId
OR
docker rmi imageId

Restart a container
docker restart containerId

To show running containers
docker ps

To show containers regardless
docker ps -a

To delete containers with ContainerID from docker ps command
docker rm 305297d7a235 ff0a5c3750b9
Deleting mulitple containers at once

To delete all the containers which exited and not running at the moment
docker rm $(docker ps -a -q -f status=exited)

Deleting all the exited containers at once can also be achieved through this command
docker container prune

Docker detached & attached

docker -d (detached) - Means the container/image will run in the background like a server should
docker -it (interactive/attache) - Means that it will run in foreground and you'll be present with a console to keep feeding the input

To stop a container
docker stop containerID/containerName

Finally, to run an image on a container

docker run -d -p 8080:80 --name containerName imageName
ie.
docker run -d -p 8080:80 --name nginxServer nginx

_WHERE
-d Detached
-p Exposing to ports
--name Display name of container when docker ps
_

Exposing ports meaning

What 8080:80 means is that:
8080 will be the port on which your local system will connect to docker ie. localhost:8080
80 will be the port which docker will request on to the container with ie. nginx:80

Dockerfile

Set of instructions, which help create a new image. Just like the images, we download from registry.
When docker build command runs, it searched for a filename Dockerfile. It can be changed, but not recommended
File Dockerfile (without any extension, case-sensitive)

Dockerfile contents
FROM baseimg
WHERE baseimg is any image i.e. ubuntu, nginx etc which is the base of this complete image

Terminologies

Images Apps that are running on the containers, i.e. ubuntu
Containers Created/Instantiated from an image
Daemon Service that is responsible for all the docker actions, i.e managing containers etc
Docker Hub Docker registry from where the images are pulled

Source
https://www.youtube.com/watch?v=Kyx2PsuwomE

Installing Nginx

docker run -it -p 3031:80 nginx
3031:80 means that 3031 port which is on this system, map it to port on which service will listen, which is 80

Installing Apache Httpd

docker pull httpd
OR
docker run -d -p 3032:80 --name apacheserver httpd

Installing MySQL

docker run -d -p 3306:3306 --name mySql-db --env MYSQL_ROOT_PASSWORD=123456 mysql
Environment variables i.e. MYSQL_ROOT_PASSWORD can be seen in https://hub.docker.com/_/mysql on docker hub

Bind Mount

docker run -d -p 3031:80 -v D:\Tutorials\Docker\website:/usr/share/nginx/html --name nginx-website nginx
Source
https://www.youtube.com/watch?time_continue=209&v=jTeDNXLFYjE&feature=emb_logo

After the path is linked, create a new index.html file, to override the image directory index.html file which is located in /usr/share/nginx/html

Dockerfile

FROM nginx:latest
WORKDIR /usr/share/nginx/html
COPY . .

Build docker image

docker image build -t hublogin/imagename [path-to-dockerfile]
ie. docker image build -t juniallomate/nginx-website .

Push image to your repository on hub.docker
docker push juniallomate/nginx-website

In case of Access Denied Error
docker login

Source
https://www.youtube.com/watch?v=bDB4IfJ31HY

Search for image from CLI

docker search --filter=stars=680 mysql
WHERE --filter-starts means only those entries which have n starts or more

Source
https://www.youtube.com/watch?v=HUpIoF_conA

Docker Compose

Tool for defining multi-container structured docker

Check docker version

docker-compose -v
Filename: docker-compose.yml

Bash into nginx:
docker exec -it container_name /bin/bash