├── .gitignore
├── Dockerfile
├── config.json
├── configmap.yml
├── deployment.yml
├── docker-compose.yml
├── frontend-svc.yml
├── ingress.yml
├── main.go
├── redis-headless.yml
├── redis.yml
└── static
    ├── Dockerfile
    ├── deployment-static.yml
    ├── index.html
    ├── js
        └── script.js
    └── static-svc.yml


/.gitignore:
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1 | go.mod
2 | go.sum


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/Dockerfile:
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 1 | FROM golang:alpine AS build-env
 2 | RUN mkdir /go/src/app && apk update && apk add git
 3 | ADD main.go go.mod go.sum /go/src/app/
 4 | WORKDIR /go/src/app
 5 | RUN go mod download && CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-extldflags "-static"' -o app .
 6 | 
 7 | FROM scratch
 8 | WORKDIR /app
 9 | COPY --from=build-env /go/src/app/app .
10 | ENTRYPOINT [ "./app" ]


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/config.json:
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1 | {
2 |     "RedisHost": "redis"
3 | }


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/configmap.yml:
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1 | apiVersion: v1
2 | kind: ConfigMap
3 | metadata:
4 |     name: app-config
5 | data:
6 |   config.json: |-
7 |     {
8 |         "RedisHost": "redis-svc"
9 |     }


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/deployment.yml:
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 1 | apiVersion: extensions/v1beta1
 2 | kind: Deployment
 3 | metadata:
 4 |     labels:
 5 |         app: frontend
 6 |     name: frontend
 7 | spec:
 8 |     replicas: 2
 9 |     selector:
10 |         matchLabels:
11 |             app: frontend
12 |     template:
13 |         metadata:
14 |             labels:
15 |                 app: frontend
16 |         spec:
17 |             containers:
18 |             - image: magalixcorp/sample-api:v1
19 |               imagePullPolicy: IfNotPresent
20 |               name: frontend
21 |               env:
22 |               - name: REDIS_PASSWORD
23 |                 valueFrom:
24 |                     secretKeyRef:
25 |                         name: redis-password
26 |                         key: redis-password
27 |               volumeMounts:
28 |               - name: config-volume
29 |                 mountPath: /app/config.json
30 |                 subPath: config.json
31 |             volumes:
32 |                 - name: config-volume
33 |                   configMap:
34 |                     name: app-config


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/docker-compose.yml:
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 1 | version: '3'
 2 | services:
 3 |   app:
 4 |     build: .
 5 |     ports:
 6 |       - "3000:3000"
 7 |     environment: 
 8 |         REDIS_PASSWORD: password123
 9 |     volumes:
10 |     - "$PWD/config.json:/app/config.json"
11 |   redis:
12 |     image: "bitnami/redis:latest"
13 |     environment: 
14 |         REDIS_PASSWORD: password123
15 | 


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/frontend-svc.yml:
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 1 | apiVersion: v1
 2 | kind: Service
 3 | metadata:
 4 |     labels:
 5 |         app: frontend
 6 |     name: frontend-svc
 7 | spec:
 8 |     ports:
 9 |     - port: 3000
10 |       protocol: TCP
11 |       targetPort: 3000
12 |     selector:
13 |         app: frontend
14 |     type: ClusterIP


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/ingress.yml:
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 1 | apiVersion: extensions/v1beta1
 2 | kind: Ingress
 3 | metadata:
 4 |     name: frontend-ingress
 5 | spec:
 6 |     rules:
 7 |     - http:
 8 |         paths:
 9 |         - path: /api
10 |           backend:
11 |             serviceName: frontend-svc
12 |             servicePort: 3000
13 |         - path: /
14 |           backend:
15 |             serviceName: static-svc
16 |             servicePort: 80


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/main.go:
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  1 | package main
  2 | 
  3 | import (
  4 | 	"encoding/json"
  5 | 	"io/ioutil"
  6 | 	"log"
  7 | 	"net/http"
  8 | 	"os"
  9 | 
 10 | 	"github.com/gomodule/redigo/redis"
 11 | 	"github.com/gorilla/handlers"
 12 | 	"github.com/gorilla/mux"
 13 | )
 14 | 
 15 | var redisHost string
 16 | var redisPort string
 17 | var redisPassword string
 18 | 
 19 | //PostData a struct for holding the the data sent in the request
 20 | type PostData struct {
 21 | 	Username string `json:"username"`
 22 | 	Message  string `json:"message"`
 23 | }
 24 | 
 25 | //Configuration is a struct for holding the application configuration data read from a JSON file
 26 | type Configuration struct {
 27 | 	RedisHost string
 28 | 	RedisPort string
 29 | }
 30 | 
 31 | func setEnv() {
 32 | 	//filename is the path to the json config file
 33 | 	file, err := os.Open("config.json")
 34 | 	if err != nil {
 35 | 		log.Fatal(err)
 36 | 	}
 37 | 	decoder := json.NewDecoder(file)
 38 | 	var configuration Configuration
 39 | 	err = decoder.Decode(&configuration)
 40 | 	if err != nil {
 41 | 		log.Fatal(err)
 42 | 	}
 43 | 	if redisHost = os.Getenv("REDIS_HOST"); redisHost == "" {
 44 | 		if redisHost = configuration.RedisHost; redisHost == "" {
 45 | 			redisHost = "localhost"
 46 | 		}
 47 | 	}
 48 | 	if redisPort = os.Getenv("REDIS_PORT"); redisPort == "" {
 49 | 		if redisPort = configuration.RedisPort; redisPort == "" {
 50 | 			redisPort = "6379"
 51 | 		}
 52 | 	}
 53 | 	redisPassword = os.Getenv("REDIS_PASSWORD")
 54 | }
 55 | 
 56 | func newServer() http.Handler {
 57 | 	r := mux.NewRouter().StrictSlash(true)
 58 | 	r.Use(commonMiddleware)
 59 | 	r.HandleFunc("/api", handlePost).Methods("POST")
 60 | 	r.HandleFunc("/api", handleQuery).Methods("GET")
 61 | 	return r
 62 | }
 63 | 
 64 | func main() {
 65 | 	setEnv()
 66 | 	var router = newServer()
 67 | 	log.Println("Server starting on port 3000")
 68 | 	// log.Fatal("Application is running", http.ListenAndServe(":3000", router))
 69 | 	log.Fatal(http.ListenAndServe(":3000", handlers.CORS(handlers.AllowedHeaders([]string{"X-Requested-With", "Content-Type", "Authorization"}), handlers.AllowedMethods([]string{"GET", "POST", "PUT", "HEAD", "OPTIONS"}), handlers.AllowedOrigins([]string{"*"}))(router)))
 70 | }
 71 | 
 72 | func handlePost(w http.ResponseWriter, r *http.Request) {
 73 | 	b, err := ioutil.ReadAll(r.Body)
 74 | 	if err != nil {
 75 | 		log.Println("Error while reading the request body:", err)
 76 | 	}
 77 | 	var newData PostData
 78 | 	json.Unmarshal(b, &newData)
 79 | 	username := newData.Username
 80 | 	message := newData.Message
 81 | 	if err != nil {
 82 | 		log.Println("Error while marhsalling the data:", err)
 83 | 	}
 84 | 	pool := newPool(true)
 85 | 	conn := pool.Get()
 86 | 	defer conn.Close()
 87 | 	err = set(conn, username, message)
 88 | 	if err != nil {
 89 | 		log.Println("Error while saving record to Redis:", err)
 90 | 	}
 91 | 	w.WriteHeader(204)
 92 | }
 93 | 
 94 | func handleQuery(w http.ResponseWriter, r *http.Request) {
 95 | 	pool := newPool(false)
 96 | 	conn := pool.Get()
 97 | 	defer conn.Close()
 98 | 	content, _ := get(conn)
 99 | 	json.NewEncoder(w).Encode(content)
100 | }
101 | 
102 | func respondWithError(w http.ResponseWriter, msg string, status int) {
103 | 	w.WriteHeader(status)
104 | 	json.NewEncoder(w).Encode(map[string]string{"message": msg})
105 | }
106 | 
107 | func newPool(write bool) *redis.Pool {
108 | 	// We need to set the Redis connection settings for testing functions individually (not passing through main() function)
109 | 	setEnv()
110 | 	return &redis.Pool{
111 | 		// Maximum number of idle connections in the pool.
112 | 		MaxIdle: 80,
113 | 		// max number of connections
114 | 		MaxActive: 12000,
115 | 		Dial: func() (redis.Conn, error) {
116 | 			c, err := redis.Dial("tcp", redisHost+":"+redisPort)
117 | 			if err != nil {
118 | 				log.Println("Could not reach Redis", err)
119 | 			}
120 | 			_, err = c.Do("AUTH", redisPassword)
121 | 			if err != nil {
122 | 				log.Println("Could not authenticate to Redis", err)
123 | 			}
124 | 			return c, err
125 | 		},
126 | 	}
127 | }
128 | func set(c redis.Conn, key string, value string) error {
129 | 	_, err := c.Do("AUTH", redisPassword)
130 | 	if err != nil {
131 | 		log.Println("Could not authenticate to Redis", err)
132 | 	}
133 | 	_, err = c.Do("SET", key, value)
134 | 	if err != nil {
135 | 		return err
136 | 	}
137 | 	return nil
138 | }
139 | 
140 | // get executes the redis GET command
141 | func get(c redis.Conn) ([]PostData, error) {
142 | 	results := []PostData{}
143 | 	_, err := c.Do("AUTH", redisPassword)
144 | 	if err != nil {
145 | 		log.Println("Could not authenticate to Redis", err)
146 | 	}
147 | 	keys, err := redis.Strings(c.Do("KEYS", "*"))
148 | 	if err != nil {
149 | 		return results, err
150 | 	}
151 | 	for _, k := range keys {
152 | 		if v, err := redis.String(c.Do("GET", k)); err == nil {
153 | 			results = append(results, PostData{k, v})
154 | 		}
155 | 	}
156 | 	return results, nil
157 | }
158 | 
159 | func commonMiddleware(next http.Handler) http.Handler {
160 | 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
161 | 		w.Header().Add("Content-Type", "application/json")
162 | 		next.ServeHTTP(w, r)
163 | 	})
164 | }
165 | 


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/redis-headless.yml:
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 1 | apiVersion: v1
 2 | kind: Service
 3 | metadata:
 4 |     labels:
 5 |         app: redis
 6 |     name: redis-svc
 7 | spec:
 8 |     clusterIP: None
 9 |     ports:
10 |     - port: 6379
11 |     selector:
12 |         app: redis


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/redis.yml:
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 1 | apiVersion: apps/v1
 2 | kind: StatefulSet
 3 | metadata:
 4 |     name: redis
 5 | spec:
 6 |     serviceName: redis-svc
 7 |     replicas: 1
 8 |     selector:
 9 |         matchLabels:
10 |             app: redis
11 |     template:
12 |         metadata:
13 |             labels:
14 |                 app: redis
15 |         spec:
16 |             containers:
17 |             - name: redis
18 |               image: bitnami/redis:latest
19 |               env:
20 |                 - name: REDIS_PASSWORD
21 |                   valueFrom:
22 |                     secretKeyRef:
23 |                         name: redis-password
24 |                         key: redis-password
25 |               ports:
26 |               - containerPort: 6379
27 |                 name: redis-port
28 |               volumeMounts:
29 |               - name: data
30 |                 mountPath: /bitnami/redis/data
31 |     volumeClaimTemplates:
32 |     - metadata:
33 |         name: data
34 |       spec:
35 |         accessModes: ["ReadWriteOnce"]
36 |         resources:
37 |             requests:
38 |                 storage: 5Gi 


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/static/Dockerfile:
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1 | FROM nginx
2 | ADD index.html /usr/share/nginx/html/
3 | ADD js /usr/share/nginx/html/js


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/static/deployment-static.yml:
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 1 | apiVersion: extensions/v1beta1
 2 | kind: Deployment
 3 | metadata:
 4 |     labels:
 5 |         app: static
 6 |     name: static
 7 | spec:
 8 |     replicas: 2
 9 |     selector:
10 |         matchLabels:
11 |             app: static
12 |     template:
13 |         metadata:
14 |             labels:
15 |                 app: static
16 |         spec:
17 |             containers:
18 |             - image: magalixcorp/static:v1
19 |               imagePullPolicy: IfNotPresent
20 |               name: static


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/static/index.html:
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 1 | <html lang="en">
 2 | 
 3 | <head>
 4 |     <meta charset="UTF-8">
 5 |     <meta name="viewport" content="width=1080, initial-scale=1.0">
 6 |     <script src="https://code.jquery.com/jquery-3.4.1.min.js"
 7 |         integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous"></script>
 8 |     <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.bundle.min.js"
 9 |         integrity="sha384-6khuMg9gaYr5AxOqhkVIODVIvm9ynTT5J4V1cfthmT+emCG6yVmEZsRHdxlotUnm"
10 |         crossorigin="anonymous"></script>
11 |     <link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet"
12 |         integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
13 |     <title>The latest messages</title>
14 | </head>
15 | 
16 | <body>
17 |     <main role="main">
18 |         <div class="jumbotron">
19 |             <div class="container">
20 |                 <div class="col-md-6">
21 |                     <h1 class="display-3">Latest messages</h1>
22 |                 </div>
23 |             </div>
24 |         </div>
25 |         <div class="container">
26 |             <div class="col-md-5">
27 |                 <ul class="list-group" id="messages">
28 |                     
29 |                 </ul>
30 |             </div>
31 |         </div>
32 |     </main>
33 |     <script src="js/script.js"></script>
34 | </body>
35 | 
36 | </html>


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/static/js/script.js:
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1 | $(document).ready(function () {
2 |     $.ajax({
3 |         url: "http://localhost/api"
4 |     }).done(function (data) {
5 |         $.each(data, function(k,v){
6 |             $("ul#messages").append("<li class='list-group-item'><strong>" + v["username"] + "</strong>:&nbsp;<i>" + v["message"] + "</i></li>");
7 |         })
8 |     });
9 | })


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/static/static-svc.yml:
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 1 | apiVersion: v1
 2 | kind: Service
 3 | metadata:
 4 |     labels:
 5 |         app: static
 6 |     name: static-svc
 7 | spec:
 8 |     ports:
 9 |     - port: 80
10 |       protocol: TCP
11 |       targetPort: 80
12 |     selector:
13 |         app: static
14 |     type: ClusterIP


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