azure: refactor to not use helpers/ pkg, validate all env/config inputs

Signed-off-by: Steve Kriss <steve@heptio.com>

vendor/github.com/Azure/azure-sdk-for-go/arm/examples/helpers/helpers.go

@@ -1,64 +0,0 @@
-package helpers
-
-// Copyright 2017 Microsoft Corporation
-//
-//  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.
-
-import (
-	"encoding/json"
-	"fmt"
-
-	"github.com/Azure/go-autorest/autorest/adal"
-	"github.com/Azure/go-autorest/autorest/azure"
-)
-
-const (
-	credentialsPath = "/.azure/credentials.json"
-)
-
-// ToJSON returns the passed item as a pretty-printed JSON string. If any JSON error occurs,
-// it returns the empty string.
-func ToJSON(v interface{}) (string, error) {
-	j, err := json.MarshalIndent(v, "", "  ")
-	return string(j), err
-}
-
-// NewServicePrincipalTokenFromCredentials creates a new ServicePrincipalToken using values of the
-// passed credentials map.
-func NewServicePrincipalTokenFromCredentials(c map[string]string, scope string) (*adal.ServicePrincipalToken, error) {
-	oauthConfig, err := adal.NewOAuthConfig(azure.PublicCloud.ActiveDirectoryEndpoint, c["AZURE_TENANT_ID"])
-	if err != nil {
-		panic(err)
-	}
-	return adal.NewServicePrincipalToken(*oauthConfig, c["AZURE_CLIENT_ID"], c["AZURE_CLIENT_SECRET"], scope)
-}
-
-func ensureValueStrings(mapOfInterface map[string]interface{}) map[string]string {
-	mapOfStrings := make(map[string]string)
-	for key, value := range mapOfInterface {
-		mapOfStrings[key] = ensureValueString(value)
-	}
-	return mapOfStrings
-}
-
-func ensureValueString(value interface{}) string {
-	if value == nil {
-		return ""
-	}
-	switch v := value.(type) {
-	case string:
-		return v
-	default:
-		return fmt.Sprintf("%v", v)
-	}
-}