http-add-on/interceptor/forward_wait_func.go

73 lines
1.8 KiB
Go

package main
import (
"context"
"fmt"
"github.com/go-logr/logr"
appsv1 "k8s.io/api/apps/v1"
"github.com/kedacore/http-add-on/pkg/k8s"
)
// forwardWaitFunc is a function that waits for a condition
// before proceeding to serve the request.
type forwardWaitFunc func(context.Context, string, string) (int, error)
func deploymentCanServe(depl appsv1.Deployment) bool {
return depl.Status.ReadyReplicas > 0
}
func newDeployReplicasForwardWaitFunc(
lggr logr.Logger,
deployCache k8s.DeploymentCache,
) forwardWaitFunc {
return func(ctx context.Context, deployNS, deployName string) (int, error) {
// get a watcher & its result channel before querying the
// deployment cache, to ensure we don't miss events
watcher, err := deployCache.Watch(deployNS, deployName)
if err != nil {
return 0, err
}
eventCh := watcher.ResultChan()
defer watcher.Stop()
deployment, err := deployCache.Get(deployNS, deployName)
if err != nil {
// if we didn't get the initial deployment state, bail out
return 0, fmt.Errorf(
"error getting state for deployment %s/%s (%s)",
deployNS,
deployName,
err,
)
}
// if there is 1 or more replica, we're done waiting
if deploymentCanServe(deployment) {
return int(deployment.Status.ReadyReplicas), nil
}
for {
select {
case event := <-eventCh:
deployment, ok := event.Object.(*appsv1.Deployment)
if !ok {
lggr.Info(
"Didn't get a deployment back in event",
)
} else if deploymentCanServe(*deployment) {
return 0, nil
}
case <-ctx.Done():
// otherwise, if the context is marked done before
// we're done waiting, fail.
return 0, fmt.Errorf(
"context marked done while waiting for deployment %s to reach > 0 replicas (%w)",
deployName,
ctx.Err(),
)
}
}
}
}