최근 Containter Orchestration 관련된 작업을 진행하고 있는데, 초기 테스트 수준의 클러스터 구성이나 솔루션의 기능 확인/검증시에 사용할 Web Server 기능을 하는 컨테이너를 주로 nginx 베이스 이미지를 사용 하고 있는데,  특정 용도에 맞게 html  파일을 수정해 주어야 하는 등 귀찮은 일 들이 많다. 도커 이미지 크기도 100MB 이상이어서 생각보다 크고... 그래서 생각한 것이 "내 맘대로 주무를 수 있는 컨테이너형 작은 웹서버" 를 만들고 언제든 사용할 수 있게 해 보자는 생각이 들었다.

[root@docker01 ~]# mkdir tmp && cd tmp

[root@docker01 tmp]# curl -LO https://storage.googleapis.com/golang/go1.7.linux-amd64.tar.gz

[root@docker01 tmp]# sudo tar -C /usr/local -xvzf go1.7.linux-amd64.tar.gz

[root@docker01 tmp]# mkdir -p ~/projects/{bin,pkg,src}

[root@docker01 tmp]# sudo vi /etc/profile.d/path.sh

[root@docker01 tmp]# vi ~/.bash_profile

[root@docker01 tmp]# source /etc/profile && source ~/.bash_profile

[root@docker01 tmp]# echo $GOPATH && echo $GOBIN

[root@docker01 ~]# cd $GOPATH

[root@docker01 src]# vi hello.go

package main

import "fmt"

func main() {

  fmt.Printf("Hello, world!!!\n")

}

[root@docker01 src]# go install $GOPATH/hello.go

[root@docker01 src]# $GOBIN/hello

Hello, world!!!

[root@docker01 src]# vi tiny-goweb.go

/*
Tiny Web server for testing k8s cluster, by Bryan Lee, 2017-08-31
*/

// A tiny web server for viewing the environment kubernetes creates for your
// containers. It exposes the filesystem and environment variables via http
// server.
//
// Modified from explorer tiny web server of k8s team.

package main

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

const (
        // Name of the application
        Name = "Tiny Webserver"
        // Version of the application
        Version = "0.7"
	// Default port
	DefaultPort = 8888
)

func main() {

	var (
		portNum = flag.Int("port", DefaultPort, "Port number to serve at.")
	)

	flag.Parse()

	// Getting hostname of Docker node or Podname
	podname, err := os.Hostname()
	if err != nil {
		log.Fatalf("Error getting hostname: %v", err)
	}

	links := []struct {
		link, desc string
	}{
		{"/", "Default landing page"},
		{"/info", "Show version & usage"},
		{"/fs", "Complete file system as seen by this container."},
		{"/env", "Environment variables as seen by this container."},
		{"/podname", "Podname or Hostname as seen by this container."},
		{"/healthz", "Just respond 200 ok for health checks"},
		{"/quit", "Cause this container to exit."},
	}

	// Handlers
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "<b> Pod/Hostname: %s Port: %d</b><br/><br/>", podname, *portNum)
	})

	http.HandleFunc("/info", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "<b> Name: %s Version: %s Port: %d</b><br/><br/>", Name, Version, *portNum)
		fmt.Fprintf(w, "<b> Kubernetes environment explorer usage</b><br/><br/>")
		for _, v := range links {
			fmt.Fprintf(w, `<a href="%v">%v: %v</a><br/>`, v.link, v.link, v.desc)
		}
	})

	http.Handle("/fs", http.StripPrefix("/fs", http.FileServer(http.Dir("/"))))
	http.HandleFunc("/env", func(w http.ResponseWriter, r *http.Request) {
		for _, v := range os.Environ() {
			fmt.Fprintf(w, "%v\n", v)
		}
	})
	http.HandleFunc("/podname", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, podname)
	})
	http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
                w.WriteHeader(200)
		fmt.Fprintf(w, "ok")
	})
	http.HandleFunc("/quit", func(w http.ResponseWriter, r *http.Request) {
		os.Exit(0)
	})

	// Start and listen
	go log.Fatal(http.ListenAndServe(fmt.Sprintf("0.0.0.0:%d", *portNum), nil))

	select {}
}

[root@docker01 src]# go install $GOPATH/tiny-goweb.go

[root@docker01 src]# $GOBIN/tiny-goweb

[root@docker01 ~]# curl http://localhost:8888/

[root@docker01 ~]# curl http://localhost:8888/quit

[root@docker01 kubeweb]# docker login -u drlee001

[root@docker01 ~]# mkdir -p ~/docker-image-works/kubeweb && cd docker-image-works/kubeweb

[root@docker01 kubeweb]# vi entrypoint.sh 

#!/bin/sh
/home/tiny-goweb $PORT_ARGS

[root@docker01 kubeweb]# vi Dockerfile 

FROM busybox

MAINTAINER Bryan Lee, <username@maildomain.com> 

COPY ./tiny-goweb /home/
COPY ./entrypoint.sh /

RUN chmod +x /entrypoint.sh
ENTRYPOINT ["/entrypoint.sh"]

[root@docker01 kubeweb]# vi build.sh 

#!/bin/bash
GOOS=linux GOARCH=386 go build ~/projects/src/tiny-goweb.go
docker build -t kubeweb .
docker tag kubeweb drlee001/kubeweb
docker push drlee001/kubeweb

[root@docker01 kubeweb]# chmod +x build.sh

[root@docker01 kubeweb]# ./build.sh 

[root@docker01 kubeweb]# ls -l

[root@docker01 kubeweb]# docker images | grep kubeweb

[root@docker01 kubeweb]# docker rmi kubeweb

[root@docker01 kubeweb]# docker rmi drlee001/kubeweb

[root@docker01 kubeweb]# docker run -it -d --name kubeweb-test -p 8888:8888 drlee001/kubeweb

[root@docker01 kubeweb]# docker ps | grep kubeweb-test

[root@docker01 ~]# curl http://localhost:8888/

[root@docker01 ~]# curl http://localhost:8888/info

[root@kubemaster kubeweb-test]# vi kubeweb-dep-svc.yaml 

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: tiny-goweb-deploy-test
spec:
  replicas: 2
  template:
    metadata:
      labels:
        app: tiny-goweb
    spec:
      containers:
      - name: tiny-goweb
        image: drlee001/kubeweb
        env:
        - name: PORT_ARGS
          value: "--port=7777"
        ports:
        - containerPort: 7777
          name: web-port
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: tiny-goweb-svc-test
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: web-port
  selector:
    app: tiny-goweb
  type: NodePort

[root@kubemaster kubeweb-test]# kubectl create -f kubeweb-dep-svc.yaml 

[root@kubemaster kubeweb-test]# kubectl get pods

[root@kubemaster ~]# kubectl get svc

[root@kubemaster ~]# curl http://10.255.10.171:30149

[root@kubemaster ~]# curl http://10.255.10.171:30149