|
| 1 | +package utils |
| 2 | + |
| 3 | +import ( |
| 4 | + "errors" |
| 5 | + "fmt" |
| 6 | + "golang.org/x/sync/singleflight" |
| 7 | + "io" |
| 8 | + "k8s.io/apimachinery/pkg/util/cache" |
| 9 | + "k8s.io/apimachinery/pkg/util/wait" |
| 10 | + "net/http" |
| 11 | + "strconv" |
| 12 | + "strings" |
| 13 | + "time" |
| 14 | +) |
| 15 | + |
| 16 | +const ( |
| 17 | + tokenURL = "http://100.100.100.200/latest/api/token" |
| 18 | + tokenTimeout = 21600 |
| 19 | +) |
| 20 | + |
| 21 | +func GetStrFromMetadata(url string) (string, error) { |
| 22 | + body, err := getWithToken(url) |
| 23 | + if err != nil { |
| 24 | + return "", err |
| 25 | + } |
| 26 | + result := strings.Split(string(body), "\n") |
| 27 | + trimResult := strings.Trim(result[0], "/") |
| 28 | + return trimResult, nil |
| 29 | +} |
| 30 | + |
| 31 | +type Error struct { |
| 32 | + URL string |
| 33 | + Code string |
| 34 | + R error |
| 35 | +} |
| 36 | + |
| 37 | +func (e *Error) Error() string { |
| 38 | + return fmt.Sprintf("get from metaserver failed code: %s, url: %s, err: %s", e.Code, e.URL, e.R) |
| 39 | +} |
| 40 | + |
| 41 | +var ( |
| 42 | + tokenCache *cache.Expiring |
| 43 | + single singleflight.Group |
| 44 | + defaultClient *http.Client |
| 45 | +) |
| 46 | + |
| 47 | +func getWithToken(url string) ([]byte, error) { |
| 48 | + |
| 49 | + skipRetry := false |
| 50 | +retry: |
| 51 | + var token string |
| 52 | + v, ok := tokenCache.Get(tokenURL) |
| 53 | + if !ok { |
| 54 | + vv, err, _ := single.Do(tokenURL, func() (interface{}, error) { |
| 55 | + out, err := withRetry(tokenURL, [][]string{ |
| 56 | + { |
| 57 | + "X-aliyun-ecs-metadata-token-ttl-seconds", strconv.Itoa(tokenTimeout), |
| 58 | + }, |
| 59 | + }) |
| 60 | + if err != nil { |
| 61 | + return nil, err |
| 62 | + } |
| 63 | + return string(out), nil |
| 64 | + }) |
| 65 | + if err != nil { |
| 66 | + return nil, err |
| 67 | + } |
| 68 | + |
| 69 | + token = vv.(string) |
| 70 | + |
| 71 | + tokenCache.Set(tokenURL, token, tokenTimeout*time.Second/2) |
| 72 | + } else { |
| 73 | + token = v.(string) |
| 74 | + } |
| 75 | + |
| 76 | + out, err := withRetry(url, [][]string{ |
| 77 | + { |
| 78 | + "X-aliyun-ecs-metadata-token", token, |
| 79 | + }, |
| 80 | + }) |
| 81 | + if err != nil { |
| 82 | + var typedErr *Error |
| 83 | + ok := errors.As(err, &typedErr) |
| 84 | + |
| 85 | + if ok && !skipRetry { |
| 86 | + if typedErr.Code == strconv.Itoa(http.StatusUnauthorized) { |
| 87 | + skipRetry = true |
| 88 | + |
| 89 | + tokenCache.Delete(tokenURL) |
| 90 | + goto retry |
| 91 | + } |
| 92 | + } |
| 93 | + |
| 94 | + return nil, err |
| 95 | + } |
| 96 | + |
| 97 | + return out, err |
| 98 | +} |
| 99 | + |
| 100 | +func withRetry(url string, headers [][]string) ([]byte, error) { |
| 101 | + var innerErr error |
| 102 | + var body []byte |
| 103 | + err := wait.ExponentialBackoff(wait.Backoff{ |
| 104 | + Duration: 500 * time.Millisecond, |
| 105 | + Factor: 1.2, |
| 106 | + Jitter: 0.1, |
| 107 | + Steps: 4, |
| 108 | + }, func() (bool, error) { |
| 109 | + var err error |
| 110 | + |
| 111 | + method := "GET" |
| 112 | + if url == tokenURL { |
| 113 | + method = "PUT" |
| 114 | + } |
| 115 | + req, err := http.NewRequest(method, url, nil) |
| 116 | + if err != nil { |
| 117 | + innerErr = &Error{ |
| 118 | + URL: url, |
| 119 | + R: err, |
| 120 | + } |
| 121 | + return false, nil |
| 122 | + } |
| 123 | + |
| 124 | + for _, h := range headers { |
| 125 | + if len(h) != 2 { |
| 126 | + return false, fmt.Errorf("invalid header") |
| 127 | + } |
| 128 | + req.Header.Set(h[0], h[1]) |
| 129 | + } |
| 130 | + |
| 131 | + resp, err := defaultClient.Do(req) |
| 132 | + if err != nil { |
| 133 | + // retryable err |
| 134 | + innerErr = &Error{ |
| 135 | + URL: url, |
| 136 | + R: err, |
| 137 | + } |
| 138 | + return false, nil |
| 139 | + } |
| 140 | + defer resp.Body.Close() |
| 141 | + |
| 142 | + // retryable err |
| 143 | + if resp.StatusCode == http.StatusTooManyRequests || |
| 144 | + resp.StatusCode >= http.StatusInternalServerError { |
| 145 | + innerErr = &Error{ |
| 146 | + URL: url, |
| 147 | + Code: strconv.Itoa(resp.StatusCode), |
| 148 | + R: nil, |
| 149 | + } |
| 150 | + return false, nil |
| 151 | + } |
| 152 | + |
| 153 | + if resp.StatusCode >= http.StatusBadRequest { |
| 154 | + innerErr = &Error{ |
| 155 | + URL: url, |
| 156 | + Code: strconv.Itoa(resp.StatusCode), |
| 157 | + R: nil, |
| 158 | + } |
| 159 | + return false, innerErr |
| 160 | + } |
| 161 | + |
| 162 | + body, err = io.ReadAll(resp.Body) |
| 163 | + if err != nil { |
| 164 | + return false, err |
| 165 | + } |
| 166 | + return true, nil |
| 167 | + }) |
| 168 | + if err != nil { |
| 169 | + if innerErr != nil { |
| 170 | + return nil, innerErr |
| 171 | + } |
| 172 | + return nil, err |
| 173 | + } |
| 174 | + return body, nil |
| 175 | +} |
| 176 | + |
| 177 | +func init() { |
| 178 | + tokenCache = cache.NewExpiring() |
| 179 | + defaultClient = &http.Client{ |
| 180 | + Transport: nil, |
| 181 | + CheckRedirect: nil, |
| 182 | + Jar: nil, |
| 183 | + Timeout: 30 * time.Second, |
| 184 | + } |
| 185 | +} |
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