feat: add configuration management and update deployment files

.gitignore

@@ -1,4 +1,5 @@
 *.exe
 *.prof
 certs/*
-helloapp
+helloapp
+.*-config.json

.linux-config-template.json

@@ -0,0 +1,8 @@
+{
+    "server": {
+        "port": 8800
+    },
+    "certs": {
+        "testKeyPath": "./certs/test.key"
+    }
+}

.vscode/launch.json

@@ -0,0 +1,17 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+    
+        {
+            "name": "Launch Package",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceFolder}",
+            "args": ["-f", ".linux-config.json"]
+        }
+    ]
+}

Dockerfile

@@ -1,5 +1,3 @@
 FROM scratch
-
+COPY helloapp /helloapp
-COPY helloapp helloapp
+CMD ["/helloapp"]
-
-CMD ["helloapp"]

cmn/conf/conf.go

@@ -0,0 +1,39 @@
+package conf
+
+import (
+	"os"
+
+	"github.com/spf13/viper"
+)
+
+func Init(file string) {
+	viper.AddConfigPath(".")
+	viper.AddConfigPath("..")
+	viper.SetConfigFile(file)
+	err := viper.ReadInConfig()
+	if err != nil {
+		panic(err)
+	}
+
+	// read test.key file
+	var keyFile *os.File
+	keyFile, err = os.Open(viper.GetString("certs.testKeyPath"))
+	if err != nil {
+		panic(err)
+	}
+	defer keyFile.Close()
+
+	var fileInfo os.FileInfo
+	fileInfo, err = keyFile.Stat()
+	if err != nil {
+		panic(err)
+	}
+	keyData := make([]byte, fileInfo.Size())
+	_, err = keyFile.Read(keyData)
+	if err != nil {
+		panic(err)
+	}
+
+	viper.Set("test.key", string(keyData))
+	
+}

deployment.yaml

@@ -2,18 +2,20 @@ apiVersion: v1
 kind: Service
 metadata:
   name: k8s-example
+  namespace: helloapp
 spec:
   selector:
     app: k8s-example
   ports:
-  - port: 8800
+    - port: 8800
-    targetPort: 8800
+      targetPort: 8800
   type: LoadBalancer
 ---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: k8s-example
+  namespace: helloapp
 spec:
   selector:
     matchLabels:
@@ -25,15 +27,45 @@ spec:
         app: k8s-example
     spec:
       containers:
-      - name: k8s-example
+        - name: k8s-example
-        image: localhost:8180/k8s-example/k8s-example:latest
+          image: localhost:8180/k8s-example/k8s-example:latest
-        imagePullPolicy: IfNotPresent
+          imagePullPolicy: IfNotPresent
-        resources:
+          resources:
-          requests:
+            requests:
-            memory: "128Mi"
+              memory: "128Mi"
-            cpu: "500m"
+              cpu: "500m"
-          limits:
+            limits:
-            memory: "128Mi"
+              memory: "128Mi"
-            cpu: "500m"
+              cpu: "500m"
-        ports:
+          ports:
-        - containerPort: 8800
+            - containerPort: 8800
+          volumeMounts:
+            - name: config-volume
+              mountPath: /config
+            - name: helloapp-test-key
+              mountPath: /certs
+          command: ["/helloapp"]
+          args: ["-f", "/config/.linux-config.json"]
+      volumes:
+        - name: config-volume
+          configMap:
+            name: k8s-example-config
+        - name: helloapp-test-key
+          secret:
+            secretName: helloapp-test-key
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: k8s-example-config
+  namespace: helloapp
+data:
+  .linux-config.json: |
+    {
+      "server": {
+        "port": 8800
+      },
+      "certs": {
+        "testKeyPath": "./certs/test.key"
+      }
+    }

go.mod

@@ -1,3 +1,20 @@
 module k8s-example
 
 go 1.25.5
+
+require github.com/spf13/viper v1.21.0
+
+require (
+	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/sagikazarmark/locafero v0.11.0 // indirect
+	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
+	github.com/spf13/afero v1.15.0 // indirect
+	github.com/spf13/cast v1.10.0 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/sys v0.29.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
+)

go.sum

@@ -0,0 +1,27 @@
+github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
+github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
+github.com/go-viper/mapstructure/v2 v2.4.0 h1:EBsztssimR/CONLSZZ04E8qAkxNYq4Qp9LvH92wZUgs=
+github.com/go-viper/mapstructure/v2 v2.4.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
+github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
+github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
+github.com/sagikazarmark/locafero v0.11.0 h1:1iurJgmM9G3PA/I+wWYIOw/5SyBtxapeHDcg+AAIFXc=
+github.com/sagikazarmark/locafero v0.11.0/go.mod h1:nVIGvgyzw595SUSUE6tvCp3YYTeHs15MvlmU87WwIik=
+github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 h1:+jumHNA0Wrelhe64i8F6HNlS8pkoyMv5sreGx2Ry5Rw=
+github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8/go.mod h1:3n1Cwaq1E1/1lhQhtRK2ts/ZwZEhjcQeJQ1RuC6Q/8U=
+github.com/spf13/afero v1.15.0 h1:b/YBCLWAJdFWJTN9cLhiXXcD7mzKn9Dm86dNnfyQw1I=
+github.com/spf13/afero v1.15.0/go.mod h1:NC2ByUVxtQs4b3sIUphxK0NioZnmxgyCrfzeuq8lxMg=
+github.com/spf13/cast v1.10.0 h1:h2x0u2shc1QuLHfxi+cTJvs30+ZAHOGRic8uyGTDWxY=
+github.com/spf13/cast v1.10.0/go.mod h1:jNfB8QC9IA6ZuY2ZjDp0KtFO2LZZlg4S/7bzP6qqeHo=
+github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
+github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/spf13/viper v1.21.0 h1:x5S+0EU27Lbphp4UKm1C+1oQO+rKx36vfCoaVebLFSU=
+github.com/spf13/viper v1.21.0/go.mod h1:P0lhsswPGWD/1lZJ9ny3fYnVqxiegrlNrEmgLjbTCAY=
+github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
+github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
+go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
+go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
+golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

hello/hello.go

@@ -1,11 +1,19 @@
 package hello
 
 import (
+	"encoding/base64"
+	"fmt"
 	"k8s-example/cmn/utils"
 	"net/http"
+
+	"github.com/spf13/viper"
 )
 
 func Handler(w http.ResponseWriter, _ *http.Request) {
 	utils.Fnc()
 	_, _ = w.Write([]byte("Hello, World!"))
+
+	encodedTestKey := base64.StdEncoding.EncodeToString([]byte(viper.GetString("test.key")))
+
+	fmt.Println(encodedTestKey)
 }

main.go

@@ -1,9 +1,13 @@
 package main
 
 import (
+	"flag"
 	"fmt"
+	"k8s-example/cmn/conf"
 	"k8s-example/hello"
 	"net/http"
+
+	"github.com/spf13/viper"
 )
 
 var (
@@ -11,10 +15,18 @@ var (
 )
 
 func main() {
+
+	// read -f parameter (config file)
+	configPath := flag.String("f", ".linux-config.json", "config file")
+	flag.Parse()
+	conf.Init(*configPath)
+
 	http.HandleFunc("/hello", hello.Handler)
 
-	fmt.Println("server on :8800, version:", version)
+	port := viper.GetInt("server.port")
-	err := http.ListenAndServe(":8800", nil)
+
+	fmt.Println("server on :", port, "version:", version)
+	err := http.ListenAndServe(fmt.Sprintf(":%d", port), nil)
 	if err != nil {
 		panic(err)
 	}