Docker save

Assume you have requirment that need to save your docker image as .tar file below are the commands for the same

Docker load

if you want load .tar file as docker image

copying the file to\from the running container

docker cp source_path containerid:destination_path

  docker cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH|-
  docker cp [OPTIONS] SRC_PATH|- CONTAINER:DEST_PATH

docker build .
To build Dockerfile present in current directory and . means send current directory as build context
docker build -f test.txt .
Assume your project has a requirment that name of the docker file should be test.txt then above is the command to build the file
docker build -t test:1.20.1 .
If you want to give name to a image then we need to use -t option basically for creating a tag
docker build --no-cache .
Assume you dont want to use intermediate layers which are there in build cache , then we need to use the above coammand
this helps when we build dockerfile once in a while
senario :- assume your dockerfile has RUN yum install git when you ran one year ago it installed git 2.17.1 but when you run this command again as this layer already exists it wont install the latest version.
So if we use --no-cache it will try build also with new layer

docker build . --build-arg a=5

         Dockerfile <br />
         
         from busybox
         run echo "test"
         ARG a
         run echo "$a"

by using above command we will be able to send arguments as launch arguments