unkin-agent
07e17791d1
A failed scan no longer advances last_synced_at; it schedules a retry from 60s with exponential backoff, honouring Retry-After/X-RateLimit-Reset.
76 lines
2.3 KiB
Go
76 lines
2.3 KiB
Go
package provider
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"net/http"
|
|
"strconv"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
syncRetryBase = time.Minute
|
|
syncRetryMax = 10 * time.Minute
|
|
)
|
|
|
|
// UpstreamStatusError is a non-success upstream response. RetryAt is the
|
|
// upstream's own retry hint (Retry-After, or X-RateLimit-Reset once the quota
|
|
// is exhausted); zero when it gave none.
|
|
type UpstreamStatusError struct {
|
|
URL string
|
|
Status int
|
|
RetryAt time.Time
|
|
}
|
|
|
|
func (e *UpstreamStatusError) Error() string {
|
|
return fmt.Sprintf("%s: status %d", e.URL, e.Status)
|
|
}
|
|
|
|
// NewUpstreamStatusError wraps a non-success response, capturing its retry hint.
|
|
func NewUpstreamStatusError(url string, resp *http.Response) *UpstreamStatusError {
|
|
e := &UpstreamStatusError{URL: url, Status: resp.StatusCode}
|
|
if ra := resp.Header.Get("Retry-After"); ra != "" {
|
|
if secs, err := strconv.Atoi(ra); err == nil {
|
|
e.RetryAt = time.Now().Add(time.Duration(secs) * time.Second)
|
|
} else if t, err := http.ParseTime(ra); err == nil {
|
|
e.RetryAt = t
|
|
}
|
|
} else if resp.Header.Get("X-RateLimit-Remaining") == "0" {
|
|
if reset, err := strconv.ParseInt(resp.Header.Get("X-RateLimit-Reset"), 10, 64); err == nil {
|
|
e.RetryAt = time.Unix(reset, 0)
|
|
}
|
|
}
|
|
return e
|
|
}
|
|
|
|
// SyncResult is a background scan's outcome, recorded when its sync lease is
|
|
// released. A failed scan keeps the prior sync time and ETag and schedules a
|
|
// retry after Backoff, doubled per consecutive failure up to MaxBackoff, and
|
|
// never earlier than RetryAt.
|
|
type SyncResult struct {
|
|
Etag string
|
|
Failed bool
|
|
RetryAt time.Time
|
|
Backoff time.Duration
|
|
MaxBackoff time.Duration
|
|
}
|
|
|
|
// NewSyncResult builds the result for a scan against a remote with the given
|
|
// mutable_ttl. The retry cap stays well below ttl, and an upstream hint is
|
|
// clamped to ttl so a bogus reset can never stall the remote longer than a
|
|
// normal sync interval would.
|
|
func NewSyncResult(etag string, scanErr error, ttl time.Duration) SyncResult {
|
|
if scanErr == nil {
|
|
return SyncResult{Etag: etag}
|
|
}
|
|
res := SyncResult{Failed: true, Backoff: syncRetryBase, MaxBackoff: min(syncRetryMax, max(syncRetryBase, ttl/4))}
|
|
var se *UpstreamStatusError
|
|
if errors.As(scanErr, &se) && !se.RetryAt.IsZero() {
|
|
res.RetryAt = se.RetryAt
|
|
if limit := time.Now().Add(ttl); res.RetryAt.After(limit) {
|
|
res.RetryAt = limit
|
|
}
|
|
}
|
|
return res
|
|
}
|