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leader.go
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leader.go
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package leaderelector
import (
"context"
"sync"
"github.com/solo-io/go-utils/contextutils"
)
type LeaderStartupAction struct {
identity Identity
actionLock sync.RWMutex
action func() error
}
func NewLeaderStartupAction(identity Identity) *LeaderStartupAction {
return &LeaderStartupAction{
identity: identity,
}
}
func (a *LeaderStartupAction) SetAction(action func() error) {
a.actionLock.Lock()
a.action = action
a.actionLock.Unlock()
}
func (a *LeaderStartupAction) GetAction() func() error {
a.actionLock.RLock()
defer a.actionLock.RUnlock()
return a.action
}
func (a *LeaderStartupAction) WatchElectionResults(ctx context.Context) {
if a.identity.Elected() == nil {
// no election channel, return early
return
}
doPerformAction := func() {
action := a.GetAction()
if action == nil {
// this case is the result of developer error
contextutils.LoggerFrom(ctx).Warnw("leader startup action not defined")
return
}
err := action()
if err != nil {
contextutils.LoggerFrom(ctx).Warnw("failed to perform leader startup action", "error", err)
}
}
go func(electionCtx context.Context) {
for {
select {
case <-electionCtx.Done():
return
case <-a.identity.Elected():
// channel is closed, signaling leadership
doPerformAction()
return
default:
// receiving from other channels would block
}
}
}(ctx)
}