Dockerfile best practices

Dockerfile-COPY.go

# Dockerfile-1
FROM golang:1.9-alpine
RUN apk --no-cache add git ca-certificates
WORKDIR /go/src/github.com/go/helloworld/
COPY app.go .
RUN go get -d -v github.com/go-sql-driver/mysql \
  && CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app . \
  && cp /go/src/github.com/go/helloworld/app /root
WORKDIR /root/
CMD ["./app"]


# Dockerfile-2a
FROM golang:1.9-alpine
RUN apk --no-cache add git
WORKDIR /go/src/github.com/go/helloworld
COPY app.go .
RUN go get -d -v github.com/go-sql-driver/mysql \
  && CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

# Dockerfile-2b
FROM alpine:latest
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY app .
CMD ["./app"]

# run.sh-2c
#!/bin/sh
echo Building go/helloworld:build
docker build -t go/helloworld:build . -f Dockerfile.build
docker create --name extract go/helloworld:build
docker cp extract:/go/src/github.com/go/helloworld/app ./app
docker rm -f extract
echo Building go/helloworld:2
docker build --no-cache -t go/helloworld:2 . -f Dockerfile.copy
rm ./app


# Dockerfile-3
FROM golang:1.9-alpine as builder
RUN apk --no-cache add git
WORKDIR /go/src/github.com/go/helloworld/
RUN go get -d -v github.com/go-sql-driver/mysql
COPY app.go .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest as prod
RUN apk --no-cache add ca-certificates
WORKDIR /root/
# Copy file from last image
# COPY --from=nginx:latest /etc/nginx/nginx.conf /nginx.conf
COPY --from=0 /go/src/github.com/go/helloworld/app .
CMD ["./app"]

Dockerfile-ONBUILD.go

# Dockerfile-1
FROM node:slim
RUN mkdir /app
WORKDIR /app
COPY ./package.json /app
RUN [ "npm", "install" ]
COPY . /app/
CMD [ "npm", "start" ]

# mynode-2
FROM node:slim
RUN mkdir /app
WORKDIR /app
CMD [ "npm", "start" ]

# Dockerfile-2
FROM my-node
COPY ./package.json /app
RUN [ "npm", "install" ]
COPY . /app/

# mynode-3
FROM node:slim
RUN mkdir /app
WORKDIR /app
ONBUILD COPY ./package.json /app
ONBUILD RUN [ "npm", "install" ]
ONBUILD COPY . /app/
CMD [ "npm", "start" ]

# Dockerfile-3
FROM my-node