Dockerfile From as code example

Example 1: docker copy from another image

FROM golang:1.7.3 AS builder
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v golang.org/x/net/html  
COPY app.go    .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/github.com/alexellis/href-counter/app .
CMD ["./app"]

Example 2: dockerfile example

FROM ubuntu:18.04
COPY . /app
RUN make /app
CMD python /app/app.py

Example 3: docker file

# getting base image from ubuntu
FROM ubuntu:18.04

RUN apt-get update

CMD ["echo", "HEY from docker image"]