e2e: add isAlreadyExistsCLIError to check known error

added isAlreadyExistsCLIError to check for known error.
if error is already exists we are considering it
as a success.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

e2e/errors_test.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package e2e
+
+import (
+	"fmt"
+	"testing"
+)
+
+// nolint:lll // error string cannot be split into multiple lines as is a
+// output from kubectl.
+func TestGetStdErr(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name                string
+		errString           string
+		expected            string
+		isAlreadyExistError bool
+	}{
+		{
+			name: "stdErr output when error is found",
+			errString: `
+error running /usr/local/bin/kubectl --server=https://192.168.39.67:8443 --kubeconfig=***** --namespace=default create -f -:
+Command stdout:
+
+stderr:
+Error from server (AlreadyExists): error when creating "STDIN": services "csi-rbdplugin-provisioner" already exists
+Error from server (AlreadyExists): error when creating "STDIN": deployments.apps "csi-rbdplugin-provisioner" already exists
+
+error:
+exit status 1`,
+			expected: `Error from server (AlreadyExists): error when creating "STDIN": services "csi-rbdplugin-provisioner" already exists
+Error from server (AlreadyExists): error when creating "STDIN": deployments.apps "csi-rbdplugin-provisioner" already exists
+
+`,
+			isAlreadyExistError: true,
+		},
+		{
+			name: "stdErr output when stderr: string is not found",
+			errString: `
+error running /usr/local/bin/kubectl --server=https://192.168.39.67:8443 --kubeconfig=***** --namespace=default create -f -:
+Command stdout:
+
+error:
+exit status 1`,
+			expected:            "",
+			isAlreadyExistError: false,
+		},
+		{
+			name: "stdErr output when error: string is not found",
+			errString: `
+error running /usr/local/bin/kubectl --server=https://192.168.39.67:8443 --kubeconfig=***** --namespace=default create -f -:
+Command stdout:
+
+stderr:
+Error from server (AlreadyExists): error when creating "STDIN": services "csi-rbdplugin-provisioner" already exists
+Error from server (AlreadyExists): error when creating "STDIN": deployments.apps "csi-rbdplugin-provisioner" already exists`,
+			expected:            "",
+			isAlreadyExistError: false,
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := getStdErr(tt.errString); got != tt.expected {
+				t.Errorf("getStdErr() output = %v, expected %v", got, tt.expected)
+			}
+
+			if got := isAlreadyExistsCLIError(fmt.Errorf("%s", tt.errString)); got != tt.isAlreadyExistError {
+				t.Errorf("isAlreadyExistsCLIError() output = %v, expected %v", got, tt.isAlreadyExistError)
+			}
+		})
+	}
+}