wip: added dotenv, updated the context logic & docker-compose (#8)

* wip: added dotenv, updated the context logic & docker-compose

* wip: added autolabel for adding the labels and updated the log terminal message

Author: manzil-infinity180

.env.example

@@ -0,0 +1 @@
+CONTEXT=k3d-mycluster

.gitignore

@@ -3,4 +3,5 @@ k8s-custom-controller
 vendor\
 .idea
 .DS_Store
-vendor
+vendor
+.env

controller/controller.go

@@ -91,6 +91,9 @@ func (c *controller) syncDeployment(ns, name string) error {
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      dep.Name,
 			Namespace: ns,
+			//Labels: map[string]string{
+			//
+			//},
 		},
 		Spec: corev1.ServiceSpec{
 			Selector: depLabels(*dep),
@@ -102,6 +105,15 @@ func (c *controller) syncDeployment(ns, name string) error {
 			},
 		},
 	}
+	labels := service.Labels
+	if labels == nil {
+		labels = make(map[string]string)
+	}
+	labelKey := "rahulxf.io/workload"
+	if _, exist := labels[labelKey]; !exist {
+		labels[labelKey] = name
+		service.SetLabels(labels)
+	}
 
 	_, err = c.clientset.CoreV1().Services(ns).Create(ctx, &service, metav1.CreateOptions{})
 	if err != nil {
@@ -125,6 +137,9 @@ func (c *controller) createIngress(ns, name string) error {
 			Annotations: map[string]string{
 				"nginx.ingress.kubernetes.io/rewrite-target": "/",
 			},
+			//Labels: map[string]string{
+			//
+			//},
 		},
 		Spec: networkingv1.IngressSpec{
 			Rules: []networkingv1.IngressRule{
@@ -152,6 +167,16 @@ func (c *controller) createIngress(ns, name string) error {
 			},
 		},
 	}
+
+	labels := ingress.Labels
+	if labels == nil {
+		labels = make(map[string]string)
+	}
+	labelKey := "rahulxf.io/workload"
+	if _, exist := labels[labelKey]; !exist {
+		labels[labelKey] = name
+		ingress.SetLabels(labels)
+	}
 	_, err := c.clientset.NetworkingV1().Ingresses(ns).Create(ctx, &ingress, metav1.CreateOptions{})
 	if err != nil {
 		return err
@@ -166,35 +191,39 @@ func depLabels(dep appsv1.Deployment) map[string]string {
 
 // Almost working
 func (c *controller) handleAdd(obj interface{}) {
-	//fmt.Println("hello add is called")
-	item, ok := obj.(*appsv1.Deployment)
+	deployment, ok := obj.(*appsv1.Deployment)
 	if !ok {
-		fmt.Println("\n Not a Deployemt")
+		fmt.Println("\n Not a Deployment")
 		return
 	}
-	fmt.Printf("Deployment \n")
-	fmt.Printf(item.Name)
-	fmt.Printf(item.Kind)
 
-	fmt.Printf("ADDED: %s", "Kind=%s, Name=%s, Namespace=%s, UID=%s", item.CreationTimestamp,
-		item.Kind, item.Name, item.Namespace, item.UID)
+	fmt.Printf("Deployment Added:\n")
+	fmt.Printf("Name: %s\n", deployment.Name)
+
+	fmt.Printf("ADDED: Name=%s, Namespace=%s, UID=%s, Created=%s\n",
+		deployment.Name,
+		deployment.Namespace,
+		string(deployment.UID),
+		deployment.CreationTimestamp)
 
 	c.queue.Add(obj)
 }
 
 // Not tested
 func (c *controller) handleDel(obj interface{}) {
-	item, ok := obj.(*appsv1.Deployment)
+	deployment, ok := obj.(*appsv1.Deployment)
 	if !ok {
-		fmt.Println("\n Not a Deployemt")
+		fmt.Println("\n Not a Deployment")
 		return
 	}
-	fmt.Printf("Deployment \n")
-	fmt.Printf(item.Name)
-	fmt.Printf(item.Kind)
+	fmt.Printf("Deployment Deleted:\n")
+	fmt.Printf("Name: %s\n", deployment.Name)
 
-	fmt.Printf("DELETED: %s", "Kind=%s, Name=%s, Namespace=%s, UID=%s", item.CreationTimestamp,
-		item.Kind, item.Name, item.Namespace, item.UID)
+	fmt.Printf("DELETED: Name=%s, Namespace=%s, UID=%s, Created=%s\n",
+		deployment.Name,
+		deployment.Namespace,
+		string(deployment.UID),
+		deployment.CreationTimestamp)
 
-	c.queue.Add(obj)
+	//c.queue.Add(obj)
 }

docker-compose.yml

@@ -6,6 +6,6 @@ services:
     volumes:
       - ${HOME}/.kube:/root/.kube
     network_mode: "host"
-#    ports:
-#      - "8000:8000"
+    env_file:
+      - .env
 

go.mod

@@ -5,6 +5,7 @@ go 1.24.0
 toolchain go1.24.3
 
 require (
+	github.com/joho/godotenv v1.5.1
 	k8s.io/api v0.33.0
 	k8s.io/apimachinery v0.33.0
 	k8s.io/client-go v0.33.0

go.sum

@@ -31,6 +31,8 @@ github.com/google/pprof v0.0.0-20241029153458-d1b30febd7db h1:097atOisP2aRj7vFgY
 github.com/google/pprof v0.0.0-20241029153458-d1b30febd7db/go.mod h1:vavhavw2zAxS5dIdcRluK6cSGGPlZynqzFM8NdvU144=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=

guide.md

@@ -0,0 +1,10 @@
+```go
+docker run --rm --name k8s-custom-controller \
+  --network host \
+  -v $HOME/.kube:/root/.kube \
+  k8s-custom-controller-controller:latest
+
+```
+```go
+kubectl create deployment my-deployment --image=nginx:latest --labels=app=nginx,env=prod
+```

main.go

@@ -2,12 +2,16 @@ package main
 
 import (
 	"fmt"
+	"github.com/joho/godotenv"
 	"github.com/manzil-infinity180/k8s-custom-controller/controller"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/client-go/tools/clientcmd/api"
+	"log"
 	"os"
+	"strings"
 	"time"
 )
 
@@ -19,6 +23,35 @@ func homeDir() string {
 	return os.Getenv("USERPROFILE") // Windows
 }
 
+func ListContexts() (string, []string, error) {
+	config, err := getKubeConfig()
+	if err != nil {
+		return "", nil, err
+	}
+	currentContext := config.CurrentContext
+	var contexts []string
+	for name := range config.Contexts {
+		if strings.Contains(name, "wds") {
+			contexts = append(contexts, name)
+		}
+	}
+	return currentContext, contexts, nil
+}
+func getKubeConfig() (*api.Config, error) {
+	kubeconfig := os.Getenv("KUBECONFIG")
+	if kubeconfig == "" {
+		if home := homeDir(); home != "" {
+			kubeconfig = fmt.Sprintf("%s/.kube/config", home)
+		}
+	}
+
+	config, err := clientcmd.LoadFromFile(kubeconfig)
+	if err != nil {
+		return nil, err
+	}
+	return config, nil
+}
+
 // GetClientSetWithContext retrieves a Kubernetes clientset and dynamic client for a specified context
 func GetClientSetWithContext(contextName string) (*kubernetes.Clientset, dynamic.Interface, error) {
 	kubeconfig := os.Getenv("KUBECONFIG")
@@ -33,7 +66,10 @@ func GetClientSetWithContext(contextName string) (*kubernetes.Clientset, dynamic
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to load kubeconfig: %v", err)
 	}
-
+	// if user does not mention any context then we will be using the current-system-context
+	if contextName == "" {
+		contextName = config.CurrentContext
+	}
 	// Check if the specified context exists
 	ctxContext := config.Contexts[contextName]
 	if ctxContext == nil {
@@ -65,8 +101,13 @@ func GetClientSetWithContext(contextName string) (*kubernetes.Clientset, dynamic
 	return clientset, dynamicClient, nil
 }
 func main() {
-	// add your context here
-	clientset, _, err := GetClientSetWithContext("cluster1")
+	// add your context in the docker-compose.yml
+	if err := godotenv.Load(); err != nil {
+		log.Println(".env file not found, assuming environment variables are set")
+	}
+	context := os.Getenv("CONTEXT")
+	fmt.Println(context)
+	clientset, _, err := GetClientSetWithContext(context)
 	if err != nil {
 		fmt.Println()
 		fmt.Errorf("%s", err.Error())

manifest/examples/deployment.yaml

@@ -0,0 +1,25 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: my-deployment2
+  labels:
+    app: nginx
+    env: prod
+    "rahulxf.io/workload": my-deployment2
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: nginx
+      "rahulxf.io/workload": my-deployment2
+  template:
+    metadata:
+      labels:
+        app: nginx
+        env: prod
+        "rahulxf.io/workload": my-deployment2
+    spec:
+      containers:
+      - name: nginx
+        image: nginx:latest
+