open-nomad/client/pluginmanager/group.go

101 lines
2.4 KiB
Go

package pluginmanager
import (
"context"
"fmt"
"sync"
"time"
log "github.com/hashicorp/go-hclog"
)
var (
// DefaultManagerReadyTimeout is the default amount of time we will wait
// for a plugin mananger to be ready before logging it and moving on.
DefaultManagerReadyTimeout = time.Second * 5
)
// 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 manangers 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)
go func() {
m.logger.Info("starting plugin manager", "plugin-type", manager.PluginType())
manager.Run()
m.logger.Info("plugin manager finished", "plugin-type", manager.PluginType())
}()
return nil
}
// Ready returns a channel which will be closed once all plugin manangers are ready.
// A timeout for waiting on each manager is given
func (m *PluginGroup) Ready(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 := m.managers[i]
wg.Add(1)
go func() {
defer wg.Done()
select {
case <-manager.Ready():
case <-ctx.Done():
m.logger.Warn("timeout waiting for plugin manager to be ready",
"plugin-type", manager.PluginType())
}
}()
}
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.shutdown = true
}