Revert "many: support killing running snap apps (canonical#14160)"

This reverts commit 5f7d584.

Signed-off-by: Zeyad Gouda <zeyad.gouda@canonical.com>

snap/info.go

@@ -37,7 +37,6 @@ import (
 	"github.com/snapcore/snapd/snap/naming"
 	"github.com/snapcore/snapd/snapdtool"
 	"github.com/snapcore/snapd/strutil"
-	"github.com/snapcore/snapd/systemd"
 	"github.com/snapcore/snapd/timeout"
 )
 
@@ -235,18 +234,6 @@ func NoneSecurityTag(snapName, uniqueName string) string {
 	return ScopedSecurityTag(snapName, "none", uniqueName)
 }
 
-// TransientScopeGlob returns the glob pattern matching
-// snap's transient scope units.
-//
-// e.g. snap.hello-world.sh-4706fe54-7802-4808-aa7e-ae8b567239e0.scope
-func TransientScopeGlob(snapName string) (string, error) {
-	snapSecurityTag := SecurityTag(snapName)
-	unitPrefix, err := systemd.SecurityTagToUnitName(snapSecurityTag)
-	// XXX: Should we also match snap components glob pattern (i.e. snap.name+*.*.scope?
-	// snap.name.*.scope
-	return unitPrefix + ".*.scope", err
-}
-
 // BaseDataDir returns the base directory for snap data locations.
 func BaseDataDir(name string) string {
 	return filepath.Join(dirs.SnapDataDir, name)

snap/info_test.go

@@ -2370,38 +2370,6 @@ hooks:
 	c.Check(hook.SecurityTag(), Equals, "snap.test-snap_instance.hook.install")
 }
 
-func (s *infoSuite) TestTransientScopeGlob(c *C) {
-	pattern, err := snap.TransientScopeGlob("some-snap")
-	c.Assert(err, IsNil)
-	c.Check(pattern, Equals, "snap.some-snap.*.scope")
-	matched, err := filepath.Match(pattern, "snap.some-snap.some-app-4706fe54-7802-4808-aa7e-ae8b567239e0.scope")
-	c.Assert(err, IsNil)
-	c.Check(matched, Equals, true)
-}
-
-func (s *infoSuite) TestTransientScopeGlobInstance(c *C) {
-	pattern, err := snap.TransientScopeGlob("some-snap_instance-1")
-	c.Assert(err, IsNil)
-	c.Check(pattern, Equals, "snap.some-snap_instance-1.*.scope")
-	// matches instance
-	matched, err := filepath.Match(pattern, "snap.some-snap_instance-1.some-app-4706fe54-7802-4808-aa7e-ae8b567239e0.scope")
-	c.Assert(err, IsNil)
-	c.Check(matched, Equals, true)
-	// but not other instances
-	matched, err = filepath.Match(pattern, "snap.some-snap_instance-2.some-app-4706fe54-7802-4808-aa7e-ae8b567239e0.scope")
-	c.Assert(err, IsNil)
-	c.Check(matched, Equals, false)
-	// or the main snap
-	matched, err = filepath.Match(pattern, "snap.some-snap.some-app-4706fe54-7802-4808-aa7e-ae8b567239e0.scope")
-	c.Assert(err, IsNil)
-	c.Check(matched, Equals, false)
-}
-
-func (s *infoSuite) TestTransientScopeError(c *C) {
-	_, err := snap.TransientScopeGlob("invalid?name")
-	c.Assert(err.Error(), Equals, "invalid character in security tag: '?'")
-}
-
 func (s *infoSuite) TestComponentMountDir(c *C) {
 	dir := snap.ComponentMountDir("comp", snap.R(1), "snap")
 	c.Check(dir, Equals, filepath.Join(dirs.SnapMountDir, "snap", "components", "mnt", "comp", "1"))

systemd/emulation.go

@@ -217,10 +217,6 @@ func (s *emulation) ListMountUnits(snapName, origin string) ([]string, error) {
 	return nil, &notImplementedError{"ListMountUnits"}
 }
 
-func (s *emulation) ListUnits(pattern string) ([]string, error) {
-	return nil, &notImplementedError{"ListUnits"}
-}
-
 func (s *emulation) Mask(service string) error {
 	_, err := systemctlCmd("--root", s.rootDir, "mask", service)
 	return err

systemd/systemd.go

@@ -430,8 +430,6 @@ type Systemd interface {
 	// ListMountUnits gets the list of targets of the mount units created by
 	// the `origin` module for the given snap
 	ListMountUnits(snapName, origin string) ([]string, error)
-	// ListUnits get the list of units currently in memory including transient units.
-	ListUnits(pattern string) ([]string, error)
 	// Mask the given service.
 	Mask(service string) error
 	// Unmask the given service.
@@ -1696,28 +1694,6 @@ func (s *systemd) ListMountUnits(snapName, origin string) ([]string, error) {
 	return mountPoints, nil
 }
 
-func (s *systemd) ListUnits(pattern string) ([]string, error) {
-	out, err := s.systemctl("list-units", "--output=json", pattern)
-	if err != nil {
-		return nil, err
-	}
-
-	type rawUnit struct {
-		UnitName string `json:"unit"`
-	}
-	var parsedUnits []rawUnit
-	err = json.Unmarshal(out, &parsedUnits)
-	if err != nil {
-		return nil, fmt.Errorf("cannot parse systemctl output: %w", err)
-	}
-
-	units := make([]string, len(parsedUnits))
-	for i, parsedUnit := range parsedUnits {
-		units[i] = parsedUnit.UnitName
-	}
-	return units, nil
-}
-
 func (s *systemd) ReloadOrRestart(serviceNames []string) error {
 	if s.mode == GlobalUserMode {
 		panic("cannot call restart with GlobalUserMode")

systemd/systemd_test.go

@@ -2311,53 +2311,6 @@ X-SnapdOrigin=%s
 	c.Check(err, IsNil)
 }
 
-func (s *SystemdTestSuite) TestListUnitsEmpty(c *C) {
-	s.outs = [][]byte{
-		[]byte("[]"),
-	}
-
-	sysd := New(UserMode, nil)
-	units, err := sysd.ListUnits("snap.some-snap.*.scope")
-	c.Check(units, HasLen, 0)
-	c.Check(err, IsNil)
-}
-
-func (s *SystemdTestSuite) TestListUnitsMalformed(c *C) {
-	s.outs = [][]byte{
-		[]byte(`[{"unit":}]
-`),
-	}
-
-	sysd := New(UserMode, nil)
-	units, err := sysd.ListUnits("snap.some-snap.*.scope")
-	c.Check(units, HasLen, 0)
-	c.Check(err, ErrorMatches, "cannot parse systemctl output:.*")
-}
-
-func (s *SystemdTestSuite) TestListUnitsHappy(c *C) {
-	type rawUnit struct {
-		UnitName string `json:"unit"`
-	}
-	var fakeUnits = []rawUnit{
-		{UnitName: "snap.some-snap.some-app-7414e1a3-6d08-43ff-a81c-6547242a78b0.scope"},
-		{UnitName: "snap.some-snap.some-app-ff81c9d9-cabb-494b-84b5-494ba945a458.scope"},
-		{UnitName: "snap.some-snap.some-other-app-f3a1d6fa-c660-4b7d-a450-aaa8849614c7.scope"},
-	}
-	systemctlOutput, err := json.Marshal(fakeUnits)
-	c.Assert(err, IsNil)
-
-	s.outs = [][]byte{systemctlOutput}
-
-	sysd := New(UserMode, nil)
-	units, err := sysd.ListUnits("some-snap.*.scope")
-	c.Assert(err, IsNil)
-	c.Check(units, DeepEquals, []string{
-		"snap.some-snap.some-app-7414e1a3-6d08-43ff-a81c-6547242a78b0.scope",
-		"snap.some-snap.some-app-ff81c9d9-cabb-494b-84b5-494ba945a458.scope",
-		"snap.some-snap.some-other-app-f3a1d6fa-c660-4b7d-a450-aaa8849614c7.scope",
-	})
-}
-
 func (s *SystemdTestSuite) TestMountHappy(c *C) {
 	sysd := New(SystemMode, nil)
 

usersession/agent/export_test.go

@@ -28,7 +28,6 @@ import (
 var (
 	SessionInfoCmd                     = sessionInfoCmd
 	ServiceControlCmd                  = serviceControlCmd
-	AppControlCmd                      = appControlCmd
 	ServiceStatusCmd                   = serviceStatusCmd
 	PendingRefreshNotificationCmd      = pendingRefreshNotificationCmd
 	FinishRefreshNotificationCmd       = finishRefreshNotificationCmd

usersession/agent/response.go

@@ -96,7 +96,6 @@ const (
 	errorKindLoginRequired  = errorKind("login-required")
 	errorKindServiceControl = errorKind("service-control")
 	errorKindServiceStatus  = errorKind("service-status")
-	errorKindAppControl     = errorKind("app-control")
 )
 
 type errorValue interface{}

usersession/agent/rest_api.go

@@ -25,10 +25,8 @@ import (
 	"mime"
 	"net/http"
 	"path/filepath"
-	"strconv"
 	"strings"
 	"sync"
-	"syscall"
 	"time"
 
 	"github.com/mvo5/goconfigparser"
@@ -48,7 +46,6 @@ var restApi = []*Command{
 	sessionInfoCmd,
 	serviceControlCmd,
 	serviceStatusCmd,
-	appControlCmd,
 	pendingRefreshNotificationCmd,
 	finishRefreshNotificationCmd,
 }
@@ -74,11 +71,6 @@ var (
 		GET:  serviceStatus,
 	}
 
-	appControlCmd = &Command{
-		Path: "/v1/app-control",
-		POST: postAppControl,
-	}
-
 	pendingRefreshNotificationCmd = &Command{
 		Path: "/v1/notifications/pending-refresh",
 		POST: postPendingRefreshNotification,
@@ -580,80 +572,3 @@ func postRefreshFinishedNotification(c *Command, r *http.Request) Response {
 	}
 	return SyncResponse(nil)
 }
-
-func collectSnapAppUnits(snapName string, sysd systemd.Systemd) (units []string, err error) {
-	pattern, err := snap.TransientScopeGlob(snapName)
-	if err != nil {
-		return nil, err
-	}
-
-	return sysd.ListUnits(pattern)
-}
-
-func appKill(inst *client.AppInstruction, sysd systemd.Systemd) Response {
-	// TODO: Use inst.Reason as a hint to explain to users what is happening
-	if inst.Signal != syscall.SIGKILL {
-		return BadRequest("only signal SIGKILL is supported")
-	}
-
-	var units []string
-	for _, snapName := range inst.Snaps {
-		if err := snap.ValidateInstanceName(snapName); err != nil {
-			return BadRequest("invalid snap instance name %q: %v", snapName, err)
-		}
-		snapAppUnits, err := collectSnapAppUnits(snapName, sysd)
-		if err != nil {
-			return InternalError("cannot collect snap app units for %q: %v", snapName, err)
-		}
-		units = append(units, snapAppUnits...)
-	}
-
-	killErrors := make(map[string]string)
-	for _, unit := range units {
-		signal := strconv.Itoa(int(inst.Signal))
-		if err := sysd.Kill(unit, signal, "all"); err != nil {
-			killErrors[unit] = err.Error()
-		}
-	}
-
-	if len(killErrors) != 0 {
-		return SyncResponse(&resp{
-			Type:   ResponseTypeError,
-			Status: 500,
-			Result: &errorResult{
-				Message: "some transient units failed to be killed",
-				Kind:    errorKindAppControl,
-				Value: map[string]interface{}{
-					"kill-errors": killErrors,
-				},
-			},
-		})
-	}
-
-	return SyncResponse(nil)
-}
-
-var appInstructionDispTable = map[string]func(*client.AppInstruction, systemd.Systemd) Response{
-	"kill": appKill,
-}
-
-func postAppControl(c *Command, r *http.Request) Response {
-	if ok, resp := validateJSONRequest(r); !ok {
-		return resp
-	}
-
-	decoder := json.NewDecoder(r.Body)
-	var inst client.AppInstruction
-	if err := decoder.Decode(&inst); err != nil {
-		return BadRequest("cannot decode request body into service instruction: %v", err)
-	}
-	impl := appInstructionDispTable[inst.Action]
-	if impl == nil {
-		return BadRequest("unknown action %s", inst.Action)
-	}
-	// Prevent multiple systemd actions from being carried out simultaneously
-	systemdLock.Lock()
-	defer systemdLock.Unlock()
-	sysd := systemd.New(systemd.UserMode, noopReporter{})
-	return impl(&inst, sysd)
-}