Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

reverseproxy: SRV dynamic upstream failover #5832

Merged
merged 5 commits into from
Mar 5, 2024
Merged

reverseproxy: SRV dynamic upstream failover #5832

Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
a61b6b7
Implement grace period, but probably needs sync
mholt Sep 19, 2023
91e5a33
Update cached freshness value
mholt Sep 21, 2023
f759a12
D'oh, actually use the grace period
mholt Sep 21, 2023
81d1c57
Merge branch 'master' into upstream-failover
mholt Oct 16, 2023
5880c3b
Fix freshness math
mholt Mar 5, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 13 additions & 0 deletions modules/caddyhttp/reverseproxy/upstreams.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,13 @@ type SRVUpstreams struct {
// Results are cached between lookups. Default: 1m
Refresh caddy.Duration `json:"refresh,omitempty"`

// If > 0 and there is an error with the lookup,
// continue to use the cached results for up to
// this long before trying again, (even though they
// are stale) instead of returning an error to the
// client. Default: 0s.
GracePeriod caddy.Duration `json:"grace_period,omitempty"`

// Configures the DNS resolver used to resolve the
// SRV address to SRV records.
Resolver *UpstreamResolver `json:"resolver,omitempty"`
Expand Down Expand Up @@ -140,6 +147,12 @@ func (su SRVUpstreams) GetUpstreams(r *http.Request) ([]*Upstream, error) {
// out and an error will be returned alongside the remaining results, if any." Thus, we
// only return an error if no records were also returned.
if len(records) == 0 {
if su.GracePeriod > 0 {
su.logger.Error("SRV lookup failed; using previously cached", zap.Error(err))
cached.freshness = time.Now().Add(time.Duration(su.GracePeriod) - time.Duration(su.Refresh))
srvs[suAddr] = cached
return allNew(cached.upstreams), nil
}
return nil, err
}
su.logger.Warn("SRV records filtered", zap.Error(err))
Expand Down
Loading