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Use cancelable contexts for cloud provider plugin refreshes (#4226)

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This commit uses a cancelable context to spawn goroutines that refresh
records from a cloud DNS provider. The Caddy shutdown routine uses the
returned cancel function to terminate existing goroutines when a USR1
reload signal is received.

Signed-off-by: Matt Kulka <mkulka@parchment.com>
This commit is contained in:
Matt Kulka 2020-10-24 05:37:01 -07:00 • committed by GitHub
parent 054c9ae1fb
commit 3168a722ca
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GPG key ID: 4AEE18F83AFDEB23
6 changed files with 12 additions and 11 deletions
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4
plugin/azure/azure.go
View file

@ -87,11 +87,11 @@ func (h *Azure) Run(ctx context.Context) error {
for { for {
select { select {
case <-ctx.Done(): case <-ctx.Done():
log.Infof("Breaking out of Azure update loop: %v", ctx.Err()) log.Debugf("Breaking out of Azure update loop for %v: %v", h.zoneNames, ctx.Err())
return return
case <-time.After(1 * time.Minute): case <-time.After(1 * time.Minute):
if err := h.updateZones(ctx); err != nil && ctx.Err() == nil { if err := h.updateZones(ctx); err != nil && ctx.Err() == nil {
log.Errorf("Failed to update zones: %v", err) log.Errorf("Failed to update zones %v: %v", h.zoneNames, err)
} }
} }
} }

3
plugin/azure/setup.go
View file

@ -25,7 +25,7 @@ func setup(c *caddy.Controller) error {
if err != nil { if err != nil {
return plugin.Error("azure", err) return plugin.Error("azure", err)
} }
ctx := context.Background() ctx, cancel := context.WithCancel(context.Background())
publicDNSClient := publicAzureDNS.NewRecordSetsClient(env.Values[auth.SubscriptionID]) publicDNSClient := publicAzureDNS.NewRecordSetsClient(env.Values[auth.SubscriptionID])
if publicDNSClient.Authorizer, err = env.GetAuthorizer(); err != nil { if publicDNSClient.Authorizer, err = env.GetAuthorizer(); err != nil {
@ -50,6 +50,7 @@ func setup(c *caddy.Controller) error {
h.Next = next h.Next = next
return h return h
}) })
c.OnShutdown(func() error { cancel(); return nil })
return nil return nil
} }

4
plugin/clouddns/clouddns.go
View file

@ -85,11 +85,11 @@ func (h *CloudDNS) Run(ctx context.Context) error {
for { for {
select { select {
case <-ctx.Done(): case <-ctx.Done():
log.Infof("Breaking out of CloudDNS update loop: %v", ctx.Err()) log.Debugf("Breaking out of CloudDNS update loop for %v: %v", h.zoneNames, ctx.Err())
return return
case <-time.After(1 * time.Minute): case <-time.After(1 * time.Minute):
if err := h.updateZones(ctx); err != nil && ctx.Err() == nil /* Don't log error if ctx expired. */ { if err := h.updateZones(ctx); err != nil && ctx.Err() == nil /* Don't log error if ctx expired. */ {
log.Errorf("Failed to update zones: %v", err) log.Errorf("Failed to update zones %v: %v", h.zoneNames, err)
} }
} }
} }

4
plugin/clouddns/setup.go
View file

@ -78,7 +78,7 @@ func setup(c *caddy.Controller) error {
} }
} }
ctx := context.Background() ctx, cancel := context.WithCancel(context.Background())
client, err := f(ctx, opt) client, err := f(ctx, opt)
if err != nil { if err != nil {
return err return err
@ -98,7 +98,7 @@ func setup(c *caddy.Controller) error {
h.Next = next h.Next = next
return h return h
}) })
c.OnShutdown(func() error { ctx.Done(); return nil }) c.OnShutdown(func() error { cancel(); return nil })
} }
return nil return nil

4
plugin/route53/route53.go
View file

@ -87,11 +87,11 @@ func (h *Route53) Run(ctx context.Context) error {
for { for {
select { select {
case <-ctx.Done(): case <-ctx.Done():
log.Infof("Breaking out of Route53 update loop: %v", ctx.Err()) log.Debugf("Breaking out of Route53 update loop for %v: %v", h.zoneNames, ctx.Err())
return return
case <-time.After(h.refresh): case <-time.After(h.refresh):
if err := h.updateZones(ctx); err != nil && ctx.Err() == nil /* Don't log error if ctx expired. */ { if err := h.updateZones(ctx); err != nil && ctx.Err() == nil /* Don't log error if ctx expired. */ {
log.Errorf("Failed to update zones: %v", err) log.Errorf("Failed to update zones %v: %v", h.zoneNames, err)
} }
} }
} }

4
plugin/route53/setup.go
View file

@ -124,7 +124,7 @@ func setup(c *caddy.Controller) error {
Client: ec2metadata.New(session), Client: ec2metadata.New(session),
}) })
client := f(credentials.NewChainCredentials(providers)) client := f(credentials.NewChainCredentials(providers))
ctx := context.Background() ctx, cancel := context.WithCancel(context.Background())
h, err := New(ctx, client, keys, refresh) h, err := New(ctx, client, keys, refresh)
if err != nil { if err != nil {
return plugin.Error("route53", c.Errf("failed to create route53 plugin: %v", err)) return plugin.Error("route53", c.Errf("failed to create route53 plugin: %v", err))
@ -137,7 +137,7 @@ func setup(c *caddy.Controller) error {
h.Next = next h.Next = next
return h return h
}) })
c.OnShutdown(func() error { ctx.Done(); return nil }) c.OnShutdown(func() error { cancel(); return nil })
} }
return nil return nil
} }