Create a Linux vm (Standard_B1s). Login into instance
curl -fsSL https://get.docker.com -o get-docker.sh
sh get-docker.sh
Install the docker and add current user to docker group
docker info
Image and Tag
Any docker image represents some application. Every application will have multiple versions.
In Docker to represent application we use name of image and to represent version we use tag. The convention <image-name>:<tag>
hello-world => hello-world:latest
If the tag is not passed docker assumes the tag to be latest
Along with Repository (image name) and tag we also have image-id
Container Options
We can perform the following operations
Create container
Delete container
start container
stop container
pause container
unpause container
Every container when created gets a unique
container id
container name
We can set the container name
docker container run --help
docker container run --name <cont-name> <image>:<tag>
To see the container running in the docker host docker container ls, to see the status of all the containers created by docker host which are not deleted docker container ls --all
When the container is created, each container gets its own
network ip address
RAM
filesystem
CPU share
Execute docker stats to know the cpu/RAM utilization
Exploring container
On the docker host execute the folowing commands
list all the process ps or ps aux
get the ip address ip addr or ifconfig (10.2.0.4)
username => qtdevops
hostname => qtdocker
Explore storage df -h & lsblk
Lets create a container and login into that docker container run -it alpine /bin/sh
Execute the following commands
find username and hostname whoami and hostname (root & 03558710c5d9)
ip address ip addr (172.17.0.4)
examine the running process ps
examine disk mounts df -h
Based on all of the observations a container looks like a linux machine inside a linux machine i.e virtual machine
Docker image contains all the necessary files to run whatever application we want inside container.
Next Steps
Lets install a java application on a linux machine
Lets try to also run the same java application inside some container and understand the docker image concept
Lets create a docker image and also understand its read-only nature.
