Build an image using Dockerfile from current dir.

$ docker build -t <image-name> .

Dockerfile keywords

`FROM`	Base image (e.g alpine)
`ENV`	Environment variables
`COPY`	Copy files from host to container (e.g. COPY . .)
`RUN`	Run during build
`EXPOSE`	Ports to expose (doesn’t publish, more of a documentation)
`CMD`	Final command run when you launch a new container from image
`WORKDIR`	Sets working directory

Everything from base images is included in new image

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

Run a container

$ docker container run -p 80:80 --rm <new-image-name>

Pull a custom Dockerfile and build an image locally

$ docker build -t yarnpkg/dev -f Dockerfile.dev .