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1 // Copyright 2014 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 package cipd | |
6 | |
7 import ( | |
8 "fmt" | |
9 "io" | |
10 "io/ioutil" | |
11 "net/http" | |
12 "os" | |
13 "path/filepath" | |
14 "time" | |
15 | |
16 "infra/libs/logging" | |
17 ) | |
18 | |
19 // FetchInstanceOptions contains parameters for FetchInstance function. | |
20 type FetchInstanceOptions struct { | |
21 // ServiceURL is root URL of the backend service, or "" to use default s
ervice. | |
22 ServiceURL string | |
23 // Client is http.Client to use to make requests, default is http.Defaul
tClient. | |
24 Client *http.Client | |
25 // Log is a logger to use for logs, default is logging.DefaultLogger. | |
26 Log logging.Logger | |
27 | |
28 // PackageName is a name of the package to fetch. | |
29 PackageName string | |
30 // InstanceID identifies an instance of the package to fetch. | |
31 InstanceID string | |
32 // Output is where to write the fetched data to. Must be nil when used w
ith FetchAndDeployInstance. | |
33 Output io.WriteSeeker | |
34 } | |
35 | |
36 // FetchInstance downloads package instance file from the repository. | |
37 func FetchInstance(options FetchInstanceOptions) (err error) { | |
38 // Fill in default options. | |
39 if options.ServiceURL == "" { | |
40 options.ServiceURL = DefaultServiceURL() | |
41 } | |
42 if options.Client == nil { | |
43 options.Client = http.DefaultClient | |
44 } | |
45 if options.Log == nil { | |
46 options.Log = logging.DefaultLogger | |
47 } | |
48 log := options.Log | |
49 remote := newRemoteService(options.Client, options.ServiceURL, log) | |
50 | |
51 // Logs the error before returning it. | |
52 defer func() { | |
53 if err != nil { | |
54 log.Errorf("cipd: failed to fetch %s (%s)", options.Pack
ageName, err) | |
55 } | |
56 }() | |
57 | |
58 // Grab fetch URL. | |
59 log.Infof("cipd: resolving %s:%s", options.PackageName, options.Instance
ID) | |
60 fetchInfo, err := remote.fetchInstance(options.PackageName, options.Inst
anceID) | |
61 if err != nil { | |
62 return | |
63 } | |
64 | |
65 // reportProgress print fetch progress, throttling the reports rate. | |
66 var prevProgress int64 = 1000 | |
67 var prevReportTs time.Time | |
68 reportProgress := func(read int64, total int64) { | |
69 now := time.Now() | |
70 progress := read * 100 / total | |
71 if progress < prevProgress || read == total || now.Sub(prevRepor
tTs) > 5*time.Second { | |
72 log.Infof("cipd: fetching %s: %d%%", options.InstanceID,
progress) | |
73 prevReportTs = now | |
74 prevProgress = progress | |
75 } | |
76 } | |
77 | |
78 // download is a separate function to be able to use deferred close. | |
79 download := func(out io.WriteSeeker, src io.ReadCloser, totalLen int64)
error { | |
80 defer src.Close() | |
81 log.Infof("cipd: fetching %s (%.1f Mb)", options.InstanceID, flo
at32(totalLen)/1024.0/1024.0) | |
82 reportProgress(0, totalLen) | |
83 _, err := io.Copy(out, &readerWithProgress{ | |
84 reader: src, | |
85 callback: func(read int64) { reportProgress(read, totalL
en) }, | |
86 }) | |
87 if err == nil { | |
88 log.Infof("cipd: successfully fetched %s", options.Insta
nceID) | |
89 } | |
90 return err | |
91 } | |
92 | |
93 // Download the actual data (several attempts). | |
94 maxAttempts := 10 | |
95 for attempt := 0; attempt < maxAttempts; attempt++ { | |
96 // Rewind output to zero offset. | |
97 _, err = options.Output.Seek(0, os.SEEK_SET) | |
98 if err != nil { | |
99 return | |
100 } | |
101 | |
102 // Send the request. | |
103 log.Infof("cipd: initiating the fetch") | |
104 var req *http.Request | |
105 var resp *http.Response | |
106 req, err = http.NewRequest("GET", fetchInfo.FetchURL, nil) | |
107 if err != nil { | |
108 return | |
109 } | |
110 req.Header.Set("User-Agent", userAgent()) | |
111 resp, err = options.Client.Do(req) | |
112 if err != nil { | |
113 return | |
114 } | |
115 | |
116 // Transient error, retry. | |
117 if resp.StatusCode == 408 || resp.StatusCode >= 500 { | |
118 resp.Body.Close() | |
119 log.Warningf("cipd: transient HTTP error %d while fetchi
ng the file", resp.StatusCode) | |
120 continue | |
121 } | |
122 | |
123 // Fatal error, abort. | |
124 if resp.StatusCode >= 400 { | |
125 resp.Body.Close() | |
126 return fmt.Errorf("Server replied with HTTP code %d", re
sp.StatusCode) | |
127 } | |
128 | |
129 // Try to fetch. | |
130 err = download(options.Output, resp.Body, resp.ContentLength) | |
131 if err != nil { | |
132 log.Warningf("cipd: transient error fetching the file: %
s", err) | |
133 continue | |
134 } | |
135 | |
136 // Success. | |
137 err = nil | |
138 return | |
139 } | |
140 | |
141 err = fmt.Errorf("All %d fetch attempts failed", maxAttempts) | |
142 return | |
143 } | |
144 | |
145 // FetchAndDeployInstance fetches the package instance and deploys it into | |
146 // a site root. It doesn't check whether the instance is already deployed. | |
147 // options.Output field is not used and must be set to nil. | |
148 func FetchAndDeployInstance(root string, options FetchInstanceOptions) error { | |
149 // Be paranoid. | |
150 err := ValidatePackageName(options.PackageName) | |
151 if err != nil { | |
152 return err | |
153 } | |
154 err = ValidateInstanceID(options.InstanceID) | |
155 if err != nil { | |
156 return err | |
157 } | |
158 | |
159 // This field is not supported. | |
160 if options.Output != nil { | |
161 return fmt.Errorf("Passed non-nil Output to FetchAndDeployInstan
ce") | |
162 } | |
163 | |
164 // Use temp file for storing package file. Delete it when done. | |
165 var instance PackageInstance | |
166 tempPath := filepath.Join(root, siteServiceDir, "tmp") | |
167 err = os.MkdirAll(tempPath, 0777) | |
168 if err != nil { | |
169 return err | |
170 } | |
171 f, err := ioutil.TempFile(tempPath, options.InstanceID) | |
172 if err != nil { | |
173 return err | |
174 } | |
175 defer func() { | |
176 // Instance takes ownership of the file, no need to close it sep
arately. | |
177 if instance == nil { | |
178 f.Close() | |
179 } | |
180 os.Remove(f.Name()) | |
181 }() | |
182 | |
183 // Fetch the package data to the provided storage. | |
184 options.Output = f | |
185 err = FetchInstance(options) | |
186 if err != nil { | |
187 return err | |
188 } | |
189 | |
190 // Open the instance, verify the instance ID. | |
191 instance, err = OpenInstance(f, options.InstanceID) | |
192 if err != nil { | |
193 return err | |
194 } | |
195 defer instance.Close() | |
196 | |
197 // Deploy it. 'defer' will take care of removing the temp file if needed
. | |
198 _, err = DeployInstance(root, instance) | |
199 return err | |
200 } | |
201 | |
202 //////////////////////////////////////////////////////////////////////////////// | |
203 | |
204 // readerWithProgress is io.Reader that calls callback whenever something is | |
205 // read from it. | |
206 type readerWithProgress struct { | |
207 reader io.Reader | |
208 total int64 | |
209 callback func(total int64) | |
210 } | |
211 | |
212 func (r *readerWithProgress) Read(p []byte) (int, error) { | |
213 n, err := r.reader.Read(p) | |
214 r.total += int64(n) | |
215 r.callback(r.total) | |
216 return n, err | |
217 } | |
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