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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,138 @@ | ||
| // Package systemctl implements some systemctl operations. | ||
| package systemctl | ||
|
|
||
| import ( | ||
| "context" | ||
| "fmt" | ||
| "log" | ||
| "sync" | ||
| "github.com/coreos/go-systemd/dbus" | ||
| ) | ||
|
|
||
| // Systemd is used to talk to systemd. | ||
| type Systemd interface { | ||
| Start(ctx context.Context, unit string) error | ||
| Stop(ctx context.Context, unit string) error | ||
| TryRestart(ctx context.Context, unit string) error | ||
| Restart(ctx context.Context, unit string) error | ||
| GetStatus(ctx context.Context, unit string) (string, error) | ||
| Close() error | ||
| GetProperty(ctx context.Context, unit, property string) (*dbus.Property, error) | ||
| Enable(files []string, runtime bool) (bool, []dbus.EnableUnitFileChange, error) | ||
| Unmask(files []string, runtime bool) ([]dbus.UnmaskUnitFileChange, error) | ||
| } | ||
|
|
||
| // NewDbus connects to systemd over dbus. | ||
| func NewDbus() (Systemd, error) { | ||
| conn, err := dbus.New() | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| return &dbusSystemd{dbus: conn, jobMap: make(map[string]([]chan string))}, nil | ||
| } | ||
|
|
||
| type dbusSystemd struct { | ||
| dbus *dbus.Conn | ||
| mu sync.Mutex | ||
| jobMap map[string]([]chan string) | ||
| } | ||
|
|
||
| var _ Systemd = &dbusSystemd{} | ||
|
|
||
| // Start is the equivalent of `systemctl start $unit`. | ||
| func (ds *dbusSystemd) Start(ctx context.Context, unit string) error { | ||
| return ds.RunCmd(ctx, ds.dbus.StartUnit, "start", unit) | ||
| } | ||
|
|
||
| func (ds *dbusSystemd) Enable(files []string, runtime bool) (bool, []dbus.EnableUnitFileChange, error) { | ||
| return ds.dbus.EnableUnitFiles(files, runtime, runtime) | ||
| } | ||
|
|
||
| func (ds *dbusSystemd) Unmask(files[] string, runtime bool) ([]dbus.UnmaskUnitFileChange, error) { | ||
| return ds.dbus.UnmaskUnitFiles(files, runtime) | ||
| } | ||
|
|
||
| // Stop is the equivalent of `systemctl stop $unit`. | ||
| func (ds *dbusSystemd) Stop(ctx context.Context, unit string) error { | ||
| return ds.RunCmd(ctx, ds.dbus.StopUnit, "stop", unit) | ||
| } | ||
|
|
||
| // TryRestart is the equivalent of `systemctl try-restart $unit`. | ||
| func (ds *dbusSystemd) TryRestart(ctx context.Context, unit string) error { | ||
| return ds.RunCmd(ctx, ds.dbus.TryRestartUnit, "tryRestart", unit) | ||
| } | ||
|
|
||
| // Restart is the equivalent of `systemctl restart $unit`. | ||
| func (ds *dbusSystemd) Restart(ctx context.Context, unit string) error { | ||
| return ds.RunCmd(ctx, ds.dbus.RestartUnit, "restart", unit) | ||
| } | ||
|
|
||
| // GetStatus gets the status string for a unit. | ||
| // Can be "active", "activating", "deactivating", "inactive" or "failed". | ||
| func (ds *dbusSystemd) GetStatus(ctx context.Context, unit string) (string, error) { | ||
| log.Printf("GetStatus for systemd unit %q", unit) | ||
| status, err := ds.dbus.ListUnitsByNames([]string{unit}) | ||
| if err != nil { | ||
| return "", err | ||
| } | ||
| if len(status) != 1 { | ||
| return "", fmt.Errorf("expected 1 unit from ListUnitsByNames, got %d", len(status)) | ||
| } | ||
| return status[0].ActiveState, nil | ||
| } | ||
|
|
||
| // GetProperty is the equivalent of `systemctl show $unit --property=$property`. | ||
| func (ds *dbusSystemd) GetProperty(ctx context.Context, unit, property string) (*dbus.Property, error) { | ||
| return ds.dbus.GetUnitProperty(unit, property) | ||
| } | ||
|
|
||
| // Close disconnects from dbus. | ||
| func (ds *dbusSystemd) Close() error { | ||
| ds.dbus.Close() | ||
| return nil | ||
| } | ||
|
|
||
| // RunCmd runs a systemctl command for a systemd unit | ||
| func (ds *dbusSystemd) RunCmd(ctx context.Context, cmdUnitFunc func(string, string, chan<- string) (int, error), cmd string, unit string) error { | ||
| progress := make(chan string, 10) | ||
|
|
||
| // When the same cmd+unit runs at the same time, the dbus library may return the same job. | ||
| // But the dbus library has a bug that in this case, it returns done to only one progress channel, | ||
| // that leaves other jobs blocking at waiting for progress. | ||
| // To get around the problem, we record all channels belonging to the same task, and send result | ||
| // after one of the channels receives result. | ||
| ds.mu.Lock() | ||
| job, err := cmdUnitFunc(unit, "replace", progress) | ||
| if err != nil { | ||
| ds.mu.Unlock() | ||
| return fmt.Errorf("%q %q failure: %v", cmd, unit, err) | ||
| } | ||
| // Job id should be enough. For safety use cmd+unit+job. | ||
| mapKey := fmt.Sprintf("%v.%v.%v", cmd, unit, job) | ||
| ds.jobMap[mapKey] = append(ds.jobMap[mapKey], progress) | ||
| ds.mu.Unlock() | ||
|
|
||
| log.Printf("%q %q jobid: %d", cmd, unit, job) | ||
| // Wait for the job to finish. | ||
| r := <-progress | ||
|
|
||
| // Populate the result to other channels with the same job id. | ||
| ds.mu.Lock() | ||
| jobChs, ok := ds.jobMap[mapKey] | ||
| if ok { | ||
| delete(ds.jobMap, mapKey) | ||
| } | ||
| ds.mu.Unlock() | ||
|
|
||
| for _, ch := range jobChs { | ||
| ch <- r | ||
| } | ||
|
|
||
| if r != "done" { | ||
| return fmt.Errorf(`%q %q status was %q, want "done"`, cmd, unit, r) | ||
| } | ||
| // Successful. | ||
| log.Printf(`%q %q status (jobid %d) was "done"`, cmd, unit, job) | ||
|
|
||
| return nil | ||
| } | ||