open-nomad/client/pluginmanager/group.go

98 lines
2.5 KiB
Go

package pluginmanager
import (
"context"
"fmt"
"sync"
log "github.com/hashicorp/go-hclog"
)
// PluginGroup is a utility struct to manage a collectively orchestrate a
// set of PluginManagers
type PluginGroup struct {
// managers is the set of managers managed, access is synced by mLock
managers []PluginManager
// shutdown indicates if shutdown has been called, access is synced by mLock
shutdown bool
// mLock gaurds managers and shutdown
mLock sync.Mutex
logger log.Logger
}
// New returns an initialized PluginGroup
func New(logger log.Logger) *PluginGroup {
return &PluginGroup{
managers: []PluginManager{},
logger: logger.Named("plugin"),
}
}
// RegisterAndRun registers the manager and starts it in a separate goroutine
func (m *PluginGroup) RegisterAndRun(manager PluginManager) error {
m.mLock.Lock()
defer m.mLock.Unlock()
if m.shutdown {
return fmt.Errorf("plugin group already shutdown")
}
m.managers = append(m.managers, manager)
m.logger.Info("starting plugin manager", "plugin-type", manager.PluginType())
manager.Run()
return nil
}
// WaitForFirstFingerprint returns a channel which will be closed once all
// plugin managers are ready. A timeout for waiting on each manager is given
func (m *PluginGroup) WaitForFirstFingerprint(ctx context.Context) (<-chan struct{}, error) {
m.mLock.Lock()
defer m.mLock.Unlock()
if m.shutdown {
return nil, fmt.Errorf("plugin group already shutdown")
}
var wg sync.WaitGroup
for i := range m.managers {
manager, ok := m.managers[i].(FingerprintingPluginManager)
if !ok {
continue
}
logger := m.logger.With("plugin-type", manager.PluginType())
wg.Add(1)
go func() {
defer wg.Done()
logger.Debug("waiting on plugin manager initial fingerprint")
select {
case <-manager.WaitForFirstFingerprint(ctx):
logger.Debug("finished plugin manager initial fingerprint")
case <-ctx.Done():
logger.Warn("timeout waiting for plugin manager to be ready")
}
}()
}
ret := make(chan struct{})
go func() {
wg.Wait()
close(ret)
}()
return ret, nil
}
// Shutdown shutsdown all registered PluginManagers in reverse order of how
// they were started.
func (m *PluginGroup) Shutdown() {
m.mLock.Lock()
defer m.mLock.Unlock()
for i := len(m.managers) - 1; i >= 0; i-- {
m.logger.Info("shutting down plugin manager", "plugin-type", m.managers[i].PluginType())
m.managers[i].Shutdown()
m.logger.Info("plugin manager finished", "plugin-type", m.managers[i].PluginType())
}
m.shutdown = true
}