51 lines
1.2 KiB
Go
51 lines
1.2 KiB
Go
package retryhttp
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import (
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"context"
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"fmt"
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"io"
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"net/http"
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"time"
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)
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func getBody(ctx context.Context, url string) ([]byte, error) {
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req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
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if err != nil {
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return nil, err
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}
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req.Header.Set("User-Agent", "CRL-Monitor/0.1")
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resp, err := http.DefaultClient.Do(req)
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if err != nil {
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return nil, err
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}
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defer resp.Body.Close()
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body, err := io.ReadAll(resp.Body)
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if err != nil {
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return nil, err
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}
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if resp.StatusCode != http.StatusOK {
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return nil, fmt.Errorf("http status %d (%s)", resp.StatusCode, string(body))
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}
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return body, nil
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}
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// Get is a simple wrapper around http.Client.Do that will retry on a fixed backoff schedule
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func Get(ctx context.Context, url string) ([]byte, error) {
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// A fixed exponential backoff schedule. The final value is zero so that we don't sleep before
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// returning the final error.
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var err error
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for _, backoff := range []int{1000, 1250, 1562, 1953, 2441, 3051, 3814, 4768, 5960, 7450, 9313, 11641, 0} {
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var body []byte
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body, err = getBody(ctx, url)
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if err == nil {
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return body, nil
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}
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time.Sleep(time.Duration(backoff) * time.Millisecond)
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}
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return nil, err
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}
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