1// Copyright 2017 Microsoft Corporation
2//
3//  Licensed under the Apache License, Version 2.0 (the "License");
4//  you may not use this file except in compliance with the License.
5//  You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9//  Unless required by applicable law or agreed to in writing, software
10//  distributed under the License is distributed on an "AS IS" BASIS,
11//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//  See the License for the specific language governing permissions and
13//  limitations under the License.
14
15package azure
16
17import (
18	"errors"
19	"fmt"
20	"net/http"
21	"net/url"
22	"strings"
23	"time"
24
25	"github.com/Azure/go-autorest/autorest"
26)
27
28// DoRetryWithRegistration tries to register the resource provider in case it is unregistered.
29// It also handles request retries
30func DoRetryWithRegistration(client autorest.Client) autorest.SendDecorator {
31	return func(s autorest.Sender) autorest.Sender {
32		return autorest.SenderFunc(func(r *http.Request) (resp *http.Response, err error) {
33			rr := autorest.NewRetriableRequest(r)
34			for currentAttempt := 0; currentAttempt < client.RetryAttempts; currentAttempt++ {
35				err = rr.Prepare()
36				if err != nil {
37					return resp, err
38				}
39
40				resp, err = autorest.SendWithSender(s, rr.Request(),
41					autorest.DoRetryForStatusCodes(client.RetryAttempts, client.RetryDuration, autorest.StatusCodesForRetry...),
42				)
43				if err != nil {
44					return resp, err
45				}
46
47				if resp.StatusCode != http.StatusConflict || client.SkipResourceProviderRegistration {
48					return resp, err
49				}
50				var re RequestError
51				err = autorest.Respond(
52					resp,
53					autorest.ByUnmarshallingJSON(&re),
54				)
55				if err != nil {
56					return resp, err
57				}
58				err = re
59
60				if re.ServiceError != nil && re.ServiceError.Code == "MissingSubscriptionRegistration" {
61					regErr := register(client, r, re)
62					if regErr != nil {
63						return resp, fmt.Errorf("failed auto registering Resource Provider: %s. Original error: %s", regErr, err)
64					}
65				}
66			}
67			return resp, err
68		})
69	}
70}
71
72func getProvider(re RequestError) (string, error) {
73	if re.ServiceError != nil && len(re.ServiceError.Details) > 0 {
74		return re.ServiceError.Details[0]["target"].(string), nil
75	}
76	return "", errors.New("provider was not found in the response")
77}
78
79func register(client autorest.Client, originalReq *http.Request, re RequestError) error {
80	subID := getSubscription(originalReq.URL.Path)
81	if subID == "" {
82		return errors.New("missing parameter subscriptionID to register resource provider")
83	}
84	providerName, err := getProvider(re)
85	if err != nil {
86		return fmt.Errorf("missing parameter provider to register resource provider: %s", err)
87	}
88	newURL := url.URL{
89		Scheme: originalReq.URL.Scheme,
90		Host:   originalReq.URL.Host,
91	}
92
93	// taken from the resources SDK
94	// with almost identical code, this sections are easier to mantain
95	// It is also not a good idea to import the SDK here
96	// https://github.com/Azure/azure-sdk-for-go/blob/9f366792afa3e0ddaecdc860e793ba9d75e76c27/arm/resources/resources/providers.go#L252
97	pathParameters := map[string]interface{}{
98		"resourceProviderNamespace": autorest.Encode("path", providerName),
99		"subscriptionId":            autorest.Encode("path", subID),
100	}
101
102	const APIVersion = "2016-09-01"
103	queryParameters := map[string]interface{}{
104		"api-version": APIVersion,
105	}
106
107	preparer := autorest.CreatePreparer(
108		autorest.AsPost(),
109		autorest.WithBaseURL(newURL.String()),
110		autorest.WithPathParameters("/subscriptions/{subscriptionId}/providers/{resourceProviderNamespace}/register", pathParameters),
111		autorest.WithQueryParameters(queryParameters),
112	)
113
114	req, err := preparer.Prepare(&http.Request{})
115	if err != nil {
116		return err
117	}
118	req = req.WithContext(originalReq.Context())
119
120	resp, err := autorest.SendWithSender(client, req,
121		autorest.DoRetryForStatusCodes(client.RetryAttempts, client.RetryDuration, autorest.StatusCodesForRetry...),
122	)
123	if err != nil {
124		return err
125	}
126
127	type Provider struct {
128		RegistrationState *string `json:"registrationState,omitempty"`
129	}
130	var provider Provider
131
132	err = autorest.Respond(
133		resp,
134		WithErrorUnlessStatusCode(http.StatusOK),
135		autorest.ByUnmarshallingJSON(&provider),
136		autorest.ByClosing(),
137	)
138	if err != nil {
139		return err
140	}
141
142	// poll for registered provisioning state
143	registrationStartTime := time.Now()
144	for err == nil && (client.PollingDuration == 0 || (client.PollingDuration != 0 && time.Since(registrationStartTime) < client.PollingDuration)) {
145		// taken from the resources SDK
146		// https://github.com/Azure/azure-sdk-for-go/blob/9f366792afa3e0ddaecdc860e793ba9d75e76c27/arm/resources/resources/providers.go#L45
147		preparer := autorest.CreatePreparer(
148			autorest.AsGet(),
149			autorest.WithBaseURL(newURL.String()),
150			autorest.WithPathParameters("/subscriptions/{subscriptionId}/providers/{resourceProviderNamespace}", pathParameters),
151			autorest.WithQueryParameters(queryParameters),
152		)
153		req, err = preparer.Prepare(&http.Request{})
154		if err != nil {
155			return err
156		}
157		req = req.WithContext(originalReq.Context())
158
159		resp, err := autorest.SendWithSender(client, req,
160			autorest.DoRetryForStatusCodes(client.RetryAttempts, client.RetryDuration, autorest.StatusCodesForRetry...),
161		)
162		if err != nil {
163			return err
164		}
165
166		err = autorest.Respond(
167			resp,
168			WithErrorUnlessStatusCode(http.StatusOK),
169			autorest.ByUnmarshallingJSON(&provider),
170			autorest.ByClosing(),
171		)
172		if err != nil {
173			return err
174		}
175
176		if provider.RegistrationState != nil &&
177			*provider.RegistrationState == "Registered" {
178			break
179		}
180
181		delayed := autorest.DelayWithRetryAfter(resp, originalReq.Context().Done())
182		if !delayed && !autorest.DelayForBackoff(client.PollingDelay, 0, originalReq.Context().Done()) {
183			return originalReq.Context().Err()
184		}
185	}
186	if client.PollingDuration != 0 && !(time.Since(registrationStartTime) < client.PollingDuration) {
187		return errors.New("polling for resource provider registration has exceeded the polling duration")
188	}
189	return err
190}
191
192func getSubscription(path string) string {
193	parts := strings.Split(path, "/")
194	for i, v := range parts {
195		if v == "subscriptions" && (i+1) < len(parts) {
196			return parts[i+1]
197		}
198	}
199	return ""
200}
201