DockerLabs Day 2.txt

FROM creates a layer from the ubuntu:15.04 Docker image.
COPY adds files from your Docker client’s current directory.
RUN builds your application with make.
CMD specifies what command to run within the container.

DockerFile FOr NodeJS
docker build -t <your username>/node-web-app .
docker images
docker run -p 49160:8080 -d <your username>/node-web-app
docker ps
docker logs <container id>

curl -i localhost:49160


Lab 10: Find the Tag of your Images
docker image ls

Lab 11: Pull an image with an specific tag
docker pull nginx:1.11.9 - pulls an nginx image with 1.11.9 version
docker pull nginx:1.11.9-alpine - pulls an nginx image with alpine distribution

docker image ls - Compare the size differences in Alpine and Debian versions

Lab 12: Find the layers of changes made in the image
docker history nginx:latest

docker history mysql

docker image inspect nginx - gives the metadata 
You can see the ports you need to Expose,the Environment variables and the default CMD.
it also shows the Archietecture 

Lab 13: Image tagging and Pushing to Docker Hub
docker image tag nginx souravlaha/nginx
docker image tag --help
docker image push souravlaha/nginx

docker login
cat .docker/config.json - Stores an Authentication token for Docoker Hub.
docker logout

Lab 14: retag and push

docker image tag souravlaha/nginx souravlaha/nginx:testing
docker image push souravlaha/nginx:testing


Lab 15: Build an image using a DockerFile
docker image build -t customnginx .

Lab 16: MOdify Expose port and rebuild
docker image build -t customnginx . - Notice using cache