Add client side rollback bits

client/snap_op.go

@@ -59,6 +59,11 @@ func (client *Client) Refresh(name string, options *SnapOptions) (changeID strin
 	return client.doSnapAction("refresh", name, options)
 }
 
+// Rollback rolls the snap back to the previous on-disk version
+func (client *Client) Rollback(name string, options *SnapOptions) (changeID string, err error) {
+	return client.doSnapAction("rollback", name, options)
+}
+
 func (client *Client) doSnapAction(actionName string, snapName string, options *SnapOptions) (changeID string, err error) {
 	action := actionData{
 		Action:      actionName,

client/snap_op_test.go

@@ -40,6 +40,7 @@ var ops = []struct {
 	{(*client.Client).Install, "install"},
 	{(*client.Client).Refresh, "refresh"},
 	{(*client.Client).Remove, "remove"},
+	{(*client.Client).Rollback, "rollback"},
 }
 
 func (cs *clientSuite) TestClientOpSnapServerError(c *check.C) {

cmd/snap/cmd_snap_op.go

@@ -201,8 +201,35 @@ func (x *cmdRefresh) Execute([]string) error {
 	return listSnaps([]string{name})
 }
 
+type cmdRollback struct {
+	Positional struct {
+		Snap string `positional-arg-name:"<snap>"`
+	} `positional-args:"yes"`
+}
+
+var shortRollbackHelp = i18n.G("Rollback the given snap to the previous version")
+var longRollbackHelp = i18n.G(`
+The rollback command will rollback the given snap to the previous version.
+`)
+
+func (x *cmdRollback) Execute(args []string) error {
+	cli := Client()
+	name := x.Positional.Snap
+	changeID, err := cli.Rollback(name, nil)
+	if err != nil {
+		return err
+	}
+
+	if _, err := wait(cli, changeID); err != nil {
+		return err
+	}
+	return listSnaps([]string{name})
+}
+
 func init() {
 	addCommand("remove", shortRemoveHelp, longRemoveHelp, func() flags.Commander { return &cmdRemove{} })
 	addCommand("install", shortInstallHelp, longInstallHelp, func() flags.Commander { return &cmdInstall{} })
 	addCommand("refresh", shortRefreshHelp, longRefreshHelp, func() flags.Commander { return &cmdRefresh{} })
+	addCommand("rollback", shortRollbackHelp, longRollbackHelp, func() flags.Commander { return &cmdRollback{} })
+
 }

cmd/snap/cmd_snap_op_test.go

@@ -172,3 +172,23 @@ func (s *SnapOpSuite) TestInstallPathDevMode(c *check.C) {
 	// ensure that the fake server api was actually hit
 	c.Check(s.srv.n, check.Equals, s.srv.total)
 }
+
+func (s *SnapOpSuite) TestRollback(c *check.C) {
+	s.srv.checker = func(r *http.Request) {
+		c.Check(r.URL.Path, check.Equals, "/v2/snaps/foo.bar")
+		c.Check(DecodedRequestBody(c, r), check.DeepEquals, map[string]interface{}{
+			"action":  "rollback",
+			"name":    "foo.bar",
+			"channel": "chan",
+		})
+	}
+
+	s.RedirectClientToTestServer(s.srv.handle)
+	rest, err := snap.Parser().ParseArgs([]string{"rollback", "foo.bar"})
+	c.Assert(err, check.IsNil)
+	c.Assert(rest, check.DeepEquals, []string{})
+	c.Check(s.Stdout(), check.Matches, `(?sm).*foo\s+1.0\s+42\s+bar.*`)
+	c.Check(s.Stderr(), check.Equals, "")
+	// ensure that the fake server api was actually hit
+	c.Check(s.srv.n, check.Equals, s.srv.total)
+}

docs/rest.md

@@ -327,7 +327,7 @@ named "snap".
 
 ### POST
 
-* Description: Install, refresh, or remove
+* Description: Install, refresh, rollback or remove
 * Access: trusted
 * Operation: async
 * Return: background operation or standard error