Dockerfile中multi-stage(多阶段构建)详解

package main
import (
 "encoding/json"
 "fmt"
 "log"
 "net/http"
 "net/url"
 "os"
 "strings"
 "golang.org/x/net/html"
)
type scrapeDataStore struct {
 Internal int `json:"internal"`
 External int `json:"external"`
}
func isInternal(parsedLink *url.URL, siteUrl *url.URL, link string) bool {
 return parsedLink.Host == siteUrl.Host || strings.Index(link, "#") == 0 || len(parsedLink.Host) == 0
}
func main() {
 urlIn := os.Getenv("url")
 if len(urlIn) == 0 {
 urlIn = "https://www.cnblogs.com/"
 }
 resp, err := http.Get(urlIn)
 scrapeData := &scrapeDataStore{}
 tokenizer := html.NewTokenizer(resp.Body)
 end := false
 for {
 tt := tokenizer.Next()
 switch {
 case tt == html.StartTagToken:
 token := tokenizer.Token()
 switch token.Data {
 case "a":
 for _, attr := range token.Attr {
  if attr.Key == "href" {
  link := attr.Val
  parsedLink, parseLinkErr := url.Parse(link)
  if parseLinkErr == nil {
  if isInternal(parsedLink, siteUrl, link) {
  scrapeData.Internal++
  } else {
  scrapeData.External++
  }
  }
  if parseLinkErr != nil {
  fmt.Println("Can't parse: " + token.Data)
  }
  }
 }
 break
 }
 case tt == html.ErrorToken:
 end = true
 break
 }
 if end {
 break
 }
 }
 data, _ := json.Marshal(&scrapeData)
 fmt.Println(string(data))
}

FROM golang:1.7.3
WORKDIR /go/src/github.com/sparkdevo/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 app .
CMD ["./app"] 

#!/bin/sh
echo Building sparkdevo/href-counter:build
# 构建编译应用程序的镜像
docker build --no-cache -t sparkdevo/href-counter:build . -f Dockerfile.build
# 创建应用程序
docker create --name extract sparkdevo/href-counter:build
# 拷贝编译好的应用程序
docker cp extract:/go/src/github.com/sparkdevo/href-counter/app ./app
docker rm -f extract

echo Building sparkdevo/href-counter:latest
# 构建运行应用程序的镜像
docker build --no-cache -t sparkdevo/href-counter:latest .

$ docker run -e url=https://www.cnblogs.com/ sparkdevo/href-counter:latest
$ docker run -e url=http://www.cnblogs.com/sparkdev/ sparkdevo/href-counter:latest

FROM golang:1.7.3
WORKDIR /go/src/github.com/sparkdevo/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=0 /go/src/github.com/sparkdevo/href-counter/app .
CMD ["./app"]

$ docker build --no-cache -t sparkdevo/href-counter:multi . -f Dockerfile.multi

$ docker run -e url=https://www.cnblogs.com/ sparkdevo/href-counter:multi
$ docker run -e url=http://www.cnblogs.com/sparkdev/ sparkdevo/href-counter:multi

FROM golang:1.7.3 as builder
WORKDIR /go/src/github.com/sparkdevo/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/sparkdevo/href-counter/app .
CMD ["./app"]