Make "--insecure-skip-tls-verify" work on all cases

In the getting started example of AWS, the master uses an IP that is changed on
stop/start. If you are playing with a cluster and stop and start the master,
the IP is changed and you can't connect again, even using the
"--insecure-skip-tls-verify" option.

This patch fixes it and makes the option work on those cases too by making
sure no CA/CAData is added when it shouldn't.

pkg/client/unversioned/clientcmd/client_config.go

@@ -305,6 +305,14 @@ func (config *DirectClientConfig) getCluster() clientcmdapi.Cluster {
 		mergo.Merge(&mergedClusterInfo, configClusterInfo)
 	}
 	mergo.Merge(&mergedClusterInfo, config.overrides.ClusterInfo)
+	// An override of --insecure-skip-tls-verify=true and no accompanying CA/CA data should clear already-set CA/CA data
+	// otherwise, a kubeconfig containing a CA reference would return an error that "CA and insecure-skip-tls-verify couldn't both be set"
+	caLen := len(config.overrides.ClusterInfo.CertificateAuthority)
+	caDataLen := len(config.overrides.ClusterInfo.CertificateAuthorityData)
+	if config.overrides.ClusterInfo.InsecureSkipTLSVerify && caLen == 0 && caDataLen == 0 {
+		mergedClusterInfo.CertificateAuthority = ""
+		mergedClusterInfo.CertificateAuthorityData = nil
+	}
 
 	return mergedClusterInfo
 }

pkg/client/unversioned/clientcmd/client_config_test.go

@@ -65,6 +65,31 @@ func createValidTestConfig() *clientcmdapi.Config {
 	return config
 }
 
+func createCAValidTestConfig() *clientcmdapi.Config {
+
+	config := createValidTestConfig()
+	config.Clusters["clean"].CertificateAuthorityData = []byte{0, 0}
+	return config
+}
+
+func TestInsecureOverridesCA(t *testing.T) {
+	config := createCAValidTestConfig()
+	clientBuilder := NewNonInteractiveClientConfig(*config, "clean", &ConfigOverrides{
+		ClusterInfo: clientcmdapi.Cluster{
+			InsecureSkipTLSVerify: true,
+		},
+	})
+
+	actualCfg, err := clientBuilder.ClientConfig()
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	matchBoolArg(true, actualCfg.Insecure, t)
+	matchStringArg("", actualCfg.TLSClientConfig.CAFile, t)
+	matchByteArg(nil, actualCfg.TLSClientConfig.CAData, t)
+}
+
 func TestMergeContext(t *testing.T) {
 	const namespace = "overriden-namespace"