Start with dockerizing example

Add a Docker file to your project

A docker file is a structural document that includes all requirements for running the project. We can specify the base image and more arguments to represent a new image just like inheritance. And base on that dockerfile, docker can build a new container, which means dockerfile inherits and acts as a blueprint for container.

Docker file setup

Docker Hub is the registry of docker images, we can ship our images to there and pull images down our machine just like github.

• There's some other alternatives like Azure Container Registry and Github Container Registry and so on.

To specify the image we need, go to a registry and check different distributions. node for example.

# set image distribution
FROM node:alpine
# copy source files to dest dir
COPY . /app
# set working dir for cmd
WORKDIR /app
# command to execute when docker image runs
CMD node app.js

Docker build

After setting dockerfile, run docker build -t <tag> <where_dockerfile_locate> in terminal where dockerfile locate. The generated image is not stored in current folder, we don't have to care about where it was stored. Use docker images or docker image ls to check existing images on your machine.

REPOSITORY     TAG       IMAGE ID       CREATED              SIZE
js-dockerize   latest    fcc3e847d662   About a minute ago   187MB

Run docker image

Run docker image using docker run <image-name>! The CMD will auto run.

Pull docker image

docker pull <image_name> do the work. And then you can go with your pulled image. docker run <image-name> can be a shortcut, if image does not exists in local, docker automatically pull from registry.