Add environment variable checks before mutation in deployment

Author: chenzhiguo

pkg/mutation/mutation_deploy.go

@@ -101,27 +101,44 @@ func injectionDeploy(request *admissionv1.AdmissionRequest) (*admissionv1.Admiss
 					}, nil
 				}
 				target := deploy.DeepCopy()
+				added := false
 				for k, v := range envs {
+					// Check if the environment variable already exists
+					exists := false
+					for _, env := range target.Spec.Template.Spec.Containers[0].Env {
+						if env.Name == k {
+							exists = true
+							break
+						}
+					}
+					// If it exists, skip adding it
+					if exists {
+						continue
+					}
+					// Add the environment variable
 					target.Spec.Template.Spec.Containers[0].Env = append(target.Spec.Template.Spec.Containers[0].Env, corev1.EnvVar{Name: k, Value: v})
+					added = true
 				}
 				log.Infof("[mutation] /injection-deploy: add envs to deployment %s/%s, envs: %v, deploy's envs: %v",
 					deploy.Name, deploy.Namespace, envs, target.Spec.Template.Spec.Containers[0].Env)
-				patchStr, err := createDeployPatch(target, &deploy)
-				if err != nil {
+				if added {
+					patchStr, err := createDeployPatch(target, &deploy)
+					if err != nil {
+						return &admissionv1.AdmissionResponse{
+							UID:     request.UID,
+							Allowed: true,
+						}, nil
+					}
 					return &admissionv1.AdmissionResponse{
 						UID:     request.UID,
 						Allowed: true,
+						Patch:   patchStr,
+						PatchType: func() *admissionv1.PatchType {
+							pt := admissionv1.PatchTypeJSONPatch
+							return &pt
+						}(),
 					}, nil
 				}
-				return &admissionv1.AdmissionResponse{
-					UID:     request.UID,
-					Allowed: true,
-					Patch:   patchStr,
-					PatchType: func() *admissionv1.PatchType {
-						pt := admissionv1.PatchTypeJSONPatch
-						return &pt
-					}(),
-				}, nil
 			} else {
 				log.Warnf("[mutation] /injection-deploy: the deployment %s/%s does not have the %s or %s label",
 					deploy.Name, deploy.Namespace, config.ServiceSpaceLabel, config.ApplicationLabel)