From 19b2a31bbe2fc5a49343fe0456d6149f598514a4 Mon Sep 17 00:00:00 2001
From: Jay Chen <1180092+jijiechen@users.noreply.github.com>
Date: Fri, 22 Dec 2023 15:54:45 +0800
Subject: [PATCH] feat(bootstrap): added E2E test case for pushing corefile
 template from cp to dp

Signed-off-by: Jay Chen <1180092+jijiechen@users.noreply.github.com>
---
 app/kuma-dp/cmd/run.go                        | 13 ---
 .../kubernetes/bootstrap/corefile_template.go | 85 +++++++++++++++++++
 .../kubernetes/kubernetes_suite_test.go       |  3 +
 3 files changed, 88 insertions(+), 13 deletions(-)
 create mode 100644 test/e2e_env/kubernetes/bootstrap/corefile_template.go

diff --git a/app/kuma-dp/cmd/run.go b/app/kuma-dp/cmd/run.go
index 27cb3c25e0c8..14127515b404 100644
--- a/app/kuma-dp/cmd/run.go
+++ b/app/kuma-dp/cmd/run.go
@@ -340,16 +340,3 @@ func writeFile(filename string, data []byte, perm os.FileMode) error {
 	}
 	return os.WriteFile(filename, data, perm)
 }
-
-func writeTempFile(dirPattern, filename string, data []byte, perm os.FileMode) (string, error) {
-	path, err := os.MkdirTemp("", dirPattern)
-	fullFileName := filepath.Join(path, filename)
-	if err != nil {
-		return "", errors.Errorf("failed to create a containing directory for %s. %v", filename, err)
-	}
-	err = os.WriteFile(fullFileName, data, perm)
-	if err != nil {
-		return "", errors.Errorf("failed to write %s to disk. %v", filename, err)
-	}
-	return fullFileName, nil
-}
diff --git a/test/e2e_env/kubernetes/bootstrap/corefile_template.go b/test/e2e_env/kubernetes/bootstrap/corefile_template.go
new file mode 100644
index 000000000000..e1e851b55622
--- /dev/null
+++ b/test/e2e_env/kubernetes/bootstrap/corefile_template.go
@@ -0,0 +1,85 @@
+package bootstrap
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/gruntwork-io/terratest/modules/random"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/kumahq/kuma/pkg/config/core"
+	k8s_util "github.com/kumahq/kuma/pkg/plugins/runtime/k8s/util"
+	. "github.com/kumahq/kuma/test/framework"
+	"github.com/kumahq/kuma/test/framework/deployments/democlient"
+)
+
+func CorefileTemplate() {
+	var zoneCluster Cluster
+	appNamespace := "dns-app"
+	appName := "demo-dp-app"
+	expectedTestText := "# this dummy corefile template is loaded from control plane"
+	configMapName := "corefile-template"
+	configMap := func(ns string) string {
+		return fmt.Sprintf(`apiVersion: v1
+kind: ConfigMap
+metadata:
+ namespace: %s
+ name: %s
+data:
+ %s: |
+    .:{{ .CoreDNSPort }} {
+    %s
+    log
+    }`, ns, configMapName, configMapName, expectedTestText)
+	}
+
+	dnsConfigDir := "/tmp/kuma-dp-config/coredns"
+	BeforeAll(func() {
+		zoneCluster = NewK8sCluster(NewTestingT(), Kuma2, Silent).
+			WithTimeout(6 * time.Second).
+			WithRetries(60)
+
+		Expect(NewClusterSetup().
+			Install(Namespace(Config.KumaNamespace)).
+			Install(YamlK8s(configMap(Config.KumaNamespace))).
+			Install(Kuma(core.Zone,
+				WithInstallationMode(HelmInstallationMode),
+				WithHelmReleaseName(fmt.Sprintf("kuma-%s", strings.ToLower(random.UniqueId()))),
+				WithHelmOpt("controlPlane.envVars.KUMA_BOOTSTRAP_SERVER_PARAMS_COREFILE_TEMPLATE_PATH",
+					dnsConfigDir+"/"+configMapName),
+				WithHelmOpt("controlPlane.extraConfigMaps[0].name", configMapName),
+				WithHelmOpt("controlPlane.extraConfigMaps[0].mountPath", dnsConfigDir),
+				WithHelmOpt("controlPlane.extraConfigMaps[0].readonly", "false"),
+			)).
+			Install(MeshKubernetes("default")).
+			Install(NamespaceWithSidecarInjection(appNamespace)).
+			Install(democlient.Install(
+				democlient.WithName(appName),
+				democlient.WithNamespace(appNamespace),
+				democlient.WithPodAnnotations(map[string]string{
+					"kuma.io/sidecar-env-vars": fmt.Sprintf("KUMA_DNS_CONFIG_DIR=%s", dnsConfigDir),
+				}),
+			)).
+
+			Setup(zoneCluster),
+		).To(Succeed())
+	})
+
+	E2EAfterAll(func() {
+		Expect(zoneCluster.DeleteKuma()).To(Succeed())
+		Expect(zoneCluster.DismissCluster()).To(Succeed())
+	})
+
+	It("should use Corefile template from control plane at data plane", func() {
+		dpPod, err := PodNameOfApp(zoneCluster, appName, appNamespace)
+		Expect(err).ToNot(HaveOccurred())
+
+		stdout, stderr, err := zoneCluster.Exec(
+			appNamespace, dpPod, k8s_util.KumaSidecarContainerName, "cat", dnsConfigDir+"/Corefile")
+		Expect(err).ToNot(HaveOccurred())
+		Expect(stderr).To(BeEmpty())
+		Expect(stdout).To(ContainSubstring(expectedTestText))
+	})
+}
diff --git a/test/e2e_env/kubernetes/kubernetes_suite_test.go b/test/e2e_env/kubernetes/kubernetes_suite_test.go
index e41c486a6425..fe475584ba97 100644
--- a/test/e2e_env/kubernetes/kubernetes_suite_test.go
+++ b/test/e2e_env/kubernetes/kubernetes_suite_test.go
@@ -3,10 +3,12 @@ package kubernetes_test
 import (
 	"testing"
 
+
 	. "github.com/onsi/ginkgo/v2"
 
 	"github.com/kumahq/kuma/pkg/test"
 	"github.com/kumahq/kuma/test/e2e_env/kubernetes/api"
+	"github.com/kumahq/kuma/test/e2e_env/kubernetes/bootstrap"
 	"github.com/kumahq/kuma/test/e2e_env/kubernetes/connectivity"
 	"github.com/kumahq/kuma/test/e2e_env/kubernetes/container_patch"
 	"github.com/kumahq/kuma/test/e2e_env/kubernetes/defaults"
@@ -49,6 +51,7 @@ var _ = E2ESynchronizedBeforeSuite(kubernetes.SetupAndGetState, kubernetes.Resto
 var _ = SynchronizedAfterSuite(func() {}, func() {})
 
 var (
+	_ = Describe("Corefile Template", bootstrap.CorefileTemplate, Ordered)
 	_ = Describe("Virtual Probes", healthcheck.VirtualProbes, Ordered)
 	_ = Describe("Gateway", gateway.Gateway, Ordered)
 	_ = Describe("Gateway - Cross-mesh", gateway.CrossMeshGatewayOnKubernetes, Ordered)