github.com/hugh712/snapd@v0.0.0-20200910133618-1a99902bd583/overlord/servicestate/service_control.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2020 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package servicestate
    21  
    22  import (
    23  	"fmt"
    24  
    25  	"github.com/snapcore/snapd/overlord/snapstate"
    26  	"github.com/snapcore/snapd/overlord/state"
    27  	"github.com/snapcore/snapd/snap"
    28  	"github.com/snapcore/snapd/wrappers"
    29  
    30  	tomb "gopkg.in/tomb.v2"
    31  )
    32  
    33  // ServiceAction encapsulates a single service-related action (such as starting,
    34  // stopping or restarting) run against services of a given snap. The action is
    35  // run for services listed in services attribute, or for all services of the
    36  // snap if services list is empty.
    37  // The names of services are app names (as defined in snap yaml).
    38  type ServiceAction struct {
    39  	SnapName       string   `json:"snap-name"`
    40  	Action         string   `json:"action"`
    41  	ActionModifier string   `json:"action-modifier,omitempty"`
    42  	Services       []string `json:"services,omitempty"`
    43  }
    44  
    45  func (m *ServiceManager) doServiceControl(t *state.Task, _ *tomb.Tomb) error {
    46  	st := t.State()
    47  	st.Lock()
    48  	defer st.Unlock()
    49  
    50  	perfTimings := state.TimingsForTask(t)
    51  	defer perfTimings.Save(st)
    52  
    53  	var sc ServiceAction
    54  	err := t.Get("service-action", &sc)
    55  	if err != nil {
    56  		return fmt.Errorf("internal error: cannot get service-action: %v", err)
    57  	}
    58  
    59  	var snapst snapstate.SnapState
    60  	if err := snapstate.Get(st, sc.SnapName, &snapst); err != nil {
    61  		return err
    62  	}
    63  	info, err := snapst.CurrentInfo()
    64  	if err != nil {
    65  		return err
    66  	}
    67  
    68  	svcs := info.Services()
    69  	if len(svcs) == 0 {
    70  		return nil
    71  	}
    72  
    73  	var services []*snap.AppInfo
    74  	if len(sc.Services) == 0 {
    75  		// no services specified, take all services of the snap
    76  		services = info.Services()
    77  	} else {
    78  		for _, svc := range sc.Services {
    79  			app := info.Apps[svc]
    80  			if app == nil {
    81  				return fmt.Errorf("no such service: %s", svc)
    82  			}
    83  			if !app.IsService() {
    84  				return fmt.Errorf("%s is not a service", svc)
    85  			}
    86  			services = append(services, app)
    87  		}
    88  	}
    89  
    90  	meter := snapstate.NewTaskProgressAdapterLocked(t)
    91  
    92  	switch sc.Action {
    93  	case "stop":
    94  		flags := &wrappers.StopServicesFlags{
    95  			Disable: sc.ActionModifier == "disable",
    96  		}
    97  		if err := wrappers.StopServices(services, flags, snap.StopReasonOther, meter, perfTimings); err != nil {
    98  			return err
    99  		}
   100  	case "start":
   101  		startupOrdered, err := snap.SortServices(services)
   102  		if err != nil {
   103  			return err
   104  		}
   105  		flags := &wrappers.StartServicesFlags{
   106  			Enable: sc.ActionModifier == "enable",
   107  		}
   108  		if err := wrappers.StartServices(startupOrdered, nil, flags, meter, perfTimings); err != nil {
   109  			return err
   110  		}
   111  	case "restart":
   112  		return wrappers.RestartServices(services, nil, meter, perfTimings)
   113  	case "reload-or-restart":
   114  		flags := &wrappers.RestartServicesFlags{Reload: true}
   115  		return wrappers.RestartServices(services, flags, meter, perfTimings)
   116  	default:
   117  		return fmt.Errorf("unhandled service action: %q", sc.Action)
   118  	}
   119  	return nil
   120  }