check if context is invalid during update-context

pkg/minikube/kubeconfig/kubeconfig.go

@@ -103,13 +103,32 @@ func Endpoint(contextName string, configPath ...string) (string, int, error) {
 	return u.Hostname(), port, nil
 }
 
+// verifyKubeconfig verifies that the cluster and context entries in the kubeconfig are valid
+func verifyKubeconfig(contextName string, hostname string, port int, configPath ...string) error {
+	if err := VerifyEndpoint(contextName, hostname, port, configPath...); err != nil {
+		return err
+	}
+	path := PathFromEnv()
+	if configPath != nil {
+		path = configPath[0]
+	}
+	apiCfg, err := readOrNew(path)
+	if err != nil {
+		return errors.Wrap(err, "read")
+	}
+	if _, ok := apiCfg.Contexts[contextName]; !ok {
+		return errors.Errorf("%q does not appear in %s", contextName, path)
+	}
+	return nil
+}
+
 // UpdateEndpoint overwrites the IP stored in kubeconfig with the provided IP.
 func UpdateEndpoint(contextName string, hostname string, port int, confpath string, ext *Extension) (bool, error) {
 	if hostname == "" {
 		return false, fmt.Errorf("empty ip")
 	}
 
-	err := VerifyEndpoint(contextName, hostname, port, confpath)
+	err := verifyKubeconfig(contextName, hostname, port, confpath)
 	if err == nil {
 		return false, nil
 	}
@@ -122,8 +141,8 @@ func UpdateEndpoint(contextName string, hostname string, port int, confpath stri
 
 	address := "https://" + hostname + ":" + strconv.Itoa(port)
 
-	// if the cluster setting is missed in the kubeconfig, create new one
-	if _, ok := cfg.Clusters[contextName]; !ok {
+	// if the cluster or context setting is missing in the kubeconfig, create it
+	if configNeedsRepair(contextName, cfg) {
 		klog.Infof("%q context is missing from %s - will repair!", contextName, confpath)
 		lp := localpath.Profile(contextName)
 		gp := localpath.MiniPath()
@@ -154,6 +173,16 @@ func UpdateEndpoint(contextName string, hostname string, port int, confpath stri
 	return true, nil
 }
 
+func configNeedsRepair(contextName string, cfg *api.Config) bool {
+	if _, ok := cfg.Clusters[contextName]; !ok {
+		return true
+	}
+	if _, ok := cfg.Contexts[contextName]; !ok {
+		return true
+	}
+	return false
+}
+
 // writeToFile encodes the configuration and writes it to the given file.
 // If the file exists, it's contents will be overwritten.
 func writeToFile(config runtime.Object, configPath ...string) error {

pkg/minikube/kubeconfig/kubeconfig_test.go

@@ -94,14 +94,14 @@ clusters:
   name: minikube
 contexts:
 - context:
-    cluster: la-croix
-    user: la-croix
-  name: la-croix
-current-context: la-croix
+    cluster: minikube
+    user: minikube
+  name: minikube
+current-context: minikube
 kind: Config
 preferences: {}
 users:
-- name: la-croix
+- name: minikube
   user:
     client-certificate: /home/la-croix/apiserver.crt
     client-key: /home/la-croix/apiserver.key
@@ -116,14 +116,14 @@ clusters:
   name: minikube
 contexts:
 - context:
-    cluster: la-croix
-    user: la-croix
-  name: la-croix
-current-context: la-croix
+    cluster: minikube
+    user: minikube
+  name: minikube
+current-context: minikube
 kind: Config
 preferences: {}
 users:
-- name: la-croix
+- name: minikube
   user:
     client-certificate: /home/la-croix/apiserver.crt
     client-key: /home/la-croix/apiserver.key
@@ -138,14 +138,14 @@ clusters:
   name: minikube
 contexts:
 - context:
-    cluster: la-croix
-    user: la-croix
-  name: la-croix
-current-context: la-croix
+    cluster: minikube
+    user: minikube
+  name: minikube
+current-context: minikube
 kind: Config
 preferences: {}
 users:
-- name: la-croix
+- name: minikube
   user:
     client-certificate: /home/la-croix/apiserver.crt
     client-key: /home/la-croix/apiserver.key
@@ -182,6 +182,70 @@ users:
     client-key: /home/la-croix/.minikube/profiles/minikube/client.key
 `)
 
+var kubeConfigMissingContext = []byte(`
+apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority: /home/la-croix/apiserver.crt
+    server: https://192.168.10.100:8443
+  name: la-croix
+- cluster:
+    certificate-authority: /home/la-croix/.minikube/ca.crt
+    server: https://192.168.10.100:8080
+  name: minikube
+contexts:
+- context:
+    cluster: la-croix
+    user: la-croix
+  name: la-croix
+current-context: la-croix
+kind: Config
+preferences: {}
+users:
+- name: la-croix
+  user:
+    client-certificate: /home/la-croix/apiserver.crt
+    client-key: /home/la-croix/apiserver.key
+- name: minikube
+  user:
+    client-certificate: /home/la-croix/.minikube/profiles/minikube/client.crt
+    client-key: /home/la-croix/.minikube/profiles/minikube/client.key
+`)
+
+var kubeConfigFixedContext = []byte(`
+apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority: /home/la-croix/apiserver.crt
+    server: https://192.168.10.100:8443
+  name: la-croix
+- cluster:
+    certificate-authority: /home/la-croix/.minikube/ca.crt
+    server: https://192.168.10.100:8080
+  name: minikube
+contexts:
+- context:
+    cluster: la-croix
+    user: la-croix
+  name: la-croix
+- context:
+    cluster: minikube
+    user: minikube
+  name: minikube
+current-context: minikube
+kind: Config
+preferences: {}
+users:
+- name: la-croix
+  user:
+    client-certificate: /home/la-croix/apiserver.crt
+    client-key: /home/la-croix/apiserver.key
+- name: minikube
+  user:
+    client-certificate: /home/la-croix/.minikube/profiles/minikube/client.crt
+    client-key: /home/la-croix/.minikube/profiles/minikube/client.key
+`)
+
 func TestUpdate(t *testing.T) {
 	setupCfg := &Settings{
 		ClusterName:          "test",
@@ -427,6 +491,27 @@ func TestUpdateIP(t *testing.T) {
 	}
 }
 
+func TestMissingContext(t *testing.T) {
+	t.Parallel()
+	os.Setenv(localpath.MinikubeHome, "/home/la-croix")
+	configFilename := tempFile(t, kubeConfigMissingContext)
+	defer os.Remove(configFilename)
+	if _, err := UpdateEndpoint("minikube", "192.168.10.100", 8080, configFilename, nil); err != nil {
+		t.Fatal(err)
+	}
+	actual, err := readOrNew(configFilename)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected, err := decode(kubeConfigFixedContext)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !configEquals(actual, expected) {
+		t.Fatalf("configs did not match: Actual:\n%+v\n Expected:\n%+v", actual, expected)
+	}
+}
+
 func TestEmptyConfig(t *testing.T) {
 	tmp := tempFile(t, []byte{})
 	defer os.Remove(tmp)