打印日志文件示例代码

Dockerfile

# Use the official golang image to create a build artifact
FROM golang:1.13 as builder

# Create app directory
RUN mkdir /app

# Add file to /app/
ADD . /app/

# Build the binary
WORKDIR /app

RUN go get -u github.com/sirupsen/logrus
RUN go get -u github.com/lestrrat-go/file-rotatelogs

RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main .

# Run service on container startup
FROM alpine:latest

WORKDIR /app

COPY --from=builder /app/main .

CMD ["/app/main"]

logfile.go

package main

import (
	"fmt"
	"log"
	"net/http"
	"os"

	rotatelogs "github.com/lestrrat-go/file-rotatelogs"
	"github.com/sirupsen/logrus"
)

func init() {
	// 创建文件日志，按天分割，日志文件仅保留一周
	w, err := rotatelogs.New("/logs/service.%Y%m%d.log")
	if err != nil {
		panic(err)
	}

	// 设置日志
	logrus.SetOutput(w)
	logrus.SetFormatter(&logrus.JSONFormatter{})
	logrus.SetReportCaller(true)
}

func handler(w http.ResponseWriter, r *http.Request) {
	t := r.URL.Query().Get("type")
	errorMsg := fmt.Sprintf("receive a request. this is [%s] log\n", t)
	switch t {
	case "error":
		logrus.Errorln(errorMsg)
	case "warn":
		logrus.Warnln(errorMsg)
	case "info":
		logrus.Infoln(errorMsg)
	case "debug":
		logrus.Debugln(errorMsg)
	case "stdout":
		fmt.Fprintf(os.Stdout, errorMsg)
	case "stderr":
		fmt.Fprintf(os.Stderr, errorMsg)
	default:
	}

	// 输出响应
	fmt.Fprintf(w, "Hello, Welcome to CloudBase!\n")
	fmt.Fprintln(w, errorMsg)
}

func main() {
	http.HandleFunc("/", handler)

	port := os.Getenv("PORT")
	if port == "" {
		port = "80"
	}

	fmt.Fprintf(os.Stdout, "start service\n")

	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
}