feat: add config file

chart/values.yaml

@@ -2,7 +2,12 @@ replicaCount: 2
 image:
   repository: registry.example.com/toto/k8s-proxy-image-swapper
   pullPolicy: IfNotPresent
-  tag: "v0.2.0"
+  tag: "v0.3.0"
+
+config: |
+  port: 8443
+  tlskeypath: "/tls/key.pem"
+  tlscertpath: "/tls/cert.pem"
 
 securityContext:
  #capabilities:

config.example.yml

@@ -0,0 +1,3 @@
+port: 8443
+tlskeypath: "/tls/key.pem"
+tlscertpath: "/tls/cert.pem"

flake.nix

@@ -12,7 +12,7 @@
         CGO_ENABLED = "0";
 
         pname = "k8s-proxy-image-swapper";
-        version = "0.2.0";
+        version = "0.3.0";
 
         src = ./.;
 

main.go

@@ -11,6 +11,7 @@ import (
 	"net/http"
 	"os"
 	"time"
+	"gopkg.in/yaml.v2"
 )
 
 func handleRoot(w http.ResponseWriter, r *http.Request) {
@@ -48,7 +49,32 @@ func handleMutation(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+type Config struct {
+	TLSCertPath string `yaml:"tlscertpath"`
+	TLSKeyPath  string `yaml:"tlskeypath"`
+	Port        string `yaml:"port"`
+}
+
 func main() {
+	if len(os.Args) == 1 {
+		fmt.Errorf("Usage : %v $CONFIG_FILE_PATH", os.Args[0])
+		return
+	}
+	configFile, err := os.Open(os.Args[1])
+	if err != nil {
+		fmt.Errorf("Error opening %v : %v", os.Args[1], err)
+		return
+	}
+	defer configFile.Close()
+
+	var config Config
+	decoder := yaml.NewDecoder(configFile)
+	err = decoder.Decode(&config)
+	if err != nil {
+		fmt.Errorf("Error reading config : %v", err)
+		return
+	}
+
 	log.Println("Starting server ...")
 
 	mux := http.NewServeMux()
@@ -57,12 +83,12 @@ func main() {
 	mux.HandleFunc("/mutate", handleMutation)
 
 	s := &http.Server{
-		Addr:           ":8443",
+		Addr:           config.Port,
 		Handler:        mux,
 		ReadTimeout:    10 * time.Second,
 		WriteTimeout:   10 * time.Second,
-		MaxHeaderBytes: 1 << 20, // 1048576
+		MaxHeaderBytes: 1 << 20, // 1_048_576
 	}
 
-	log.Fatal(s.ListenAndServeTLS("/tls/cert.pem", "/tls/key.pem"))
+	log.Fatal(s.ListenAndServeTLS(config.TLSCertPath, config.TLSKeyPath))
 }