func (s *MachineSuite) TestWatchUnits(c *C) {
// Start a watch on an empty machine; check no units reported.
w := s.machine.WatchUnits()
defer testing.AssertStop(c, w)
wc := testing.NewLaxStringsWatcherC(c, s.State, w)
wc.AssertChange()
wc.AssertNoChange()
// Change machine; no change.
err := s.machine.SetProvisioned("cheese", "fake_nonce", nil)
c.Assert(err, IsNil)
wc.AssertNoChange()
// Assign a unit (to a separate instance); change detected.
mysql, err := s.State.AddService("mysql", s.AddTestingCharm(c, "mysql"))
c.Assert(err, IsNil)
mysql0, err := mysql.AddUnit()
c.Assert(err, IsNil)
machine, err := s.State.Machine(s.machine.Id())
c.Assert(err, IsNil)
err = mysql0.AssignToMachine(machine)
c.Assert(err, IsNil)
wc.AssertChange("mysql/0")
wc.AssertNoChange()
// Change the unit; no change.
err = mysql0.SetStatus(params.StatusStarted, "")
c.Assert(err, IsNil)
wc.AssertNoChange()
// Assign another unit and make the first Dying; check both changes detected.
mysql1, err := mysql.AddUnit()
c.Assert(err, IsNil)
err = mysql1.AssignToMachine(machine)
c.Assert(err, IsNil)
err = mysql0.Destroy()
c.Assert(err, IsNil)
wc.AssertChange("mysql/0", "mysql/1")
wc.AssertNoChange()
// Add a subordinate to the Alive unit; change detected.
logging, err := s.State.AddService("logging", s.AddTestingCharm(c, "logging"))
c.Assert(err, IsNil)
eps, err := s.State.InferEndpoints([]string{"mysql", "logging"})
c.Assert(err, IsNil)
rel, err := s.State.AddRelation(eps...)
c.Assert(err, IsNil)
mysqlru1, err := rel.Unit(mysql1)
c.Assert(err, IsNil)
err = mysqlru1.EnterScope(nil)
c.Assert(err, IsNil)
logging0, err := logging.Unit("logging/0")
c.Assert(err, IsNil)
wc.AssertChange("logging/0")
wc.AssertNoChange()
// Change the subordinate; no change.
err = logging0.SetStatus(params.StatusStarted, "")
c.Assert(err, IsNil)
wc.AssertNoChange()
// Make the Dying unit Dead; change detected.
err = mysql0.EnsureDead()
c.Assert(err, IsNil)
wc.AssertChange("mysql/0")
wc.AssertNoChange()
// Stop watcher; check Changes chan closed.
testing.AssertStop(c, w)
wc.AssertClosed()
// Start a fresh watcher; check all units reported.
w = s.machine.WatchUnits()
defer testing.AssertStop(c, w)
wc = testing.NewLaxStringsWatcherC(c, s.State, w)
wc.AssertChange("mysql/0", "mysql/1", "logging/0")
wc.AssertNoChange()
// Remove the Dead unit; no change.
err = mysql0.Remove()
c.Assert(err, IsNil)
wc.AssertNoChange()
// Destroy the subordinate; change detected.
err = logging0.Destroy()
c.Assert(err, IsNil)
wc.AssertChange("logging/0")
wc.AssertNoChange()
// Unassign the principal; check subordinate departure also reported.
err = mysql1.UnassignFromMachine()
c.Assert(err, IsNil)
wc.AssertChange("mysql/1", "logging/0")
wc.AssertNoChange()
}
func (s *UnitSuite) TestWatchSubordinates(c *C) {
w := s.unit.WatchSubordinateUnits()
defer testing.AssertStop(c, w)
wc := testing.NewLaxStringsWatcherC(c, s.State, w)
wc.AssertChange()
wc.AssertNoChange()
// Add a couple of subordinates, check change.
subCharm := s.AddTestingCharm(c, "logging")
var subUnits []*state.Unit
for i := 0; i < 2; i++ {
// Note: subordinate units can only be created as a side effect of a
// principal entering scope; and a given principal can only have a
// single subordinate unit of each service.
name := "logging" + strconv.Itoa(i)
subSvc, err := s.State.AddService(name, subCharm)
c.Assert(err, IsNil)
eps, err := s.State.InferEndpoints([]string{name, "wordpress"})
c.Assert(err, IsNil)
rel, err := s.State.AddRelation(eps...)
c.Assert(err, IsNil)
ru, err := rel.Unit(s.unit)
c.Assert(err, IsNil)
err = ru.EnterScope(nil)
c.Assert(err, IsNil)
units, err := subSvc.AllUnits()
c.Assert(err, IsNil)
c.Assert(units, HasLen, 1)
subUnits = append(subUnits, units[0])
}
wc.AssertChange(subUnits[0].Name(), subUnits[1].Name())
wc.AssertNoChange()
// Set one to Dying, check change.
err := subUnits[0].Destroy()
c.Assert(err, IsNil)
wc.AssertChange(subUnits[0].Name())
wc.AssertNoChange()
// Set both to Dead, and remove one; check change.
err = subUnits[0].EnsureDead()
c.Assert(err, IsNil)
err = subUnits[1].EnsureDead()
c.Assert(err, IsNil)
err = subUnits[1].Remove()
c.Assert(err, IsNil)
wc.AssertChange(subUnits[0].Name(), subUnits[1].Name())
wc.AssertNoChange()
// Stop watcher, check closed.
testing.AssertStop(c, w)
wc.AssertClosed()
// Start a new watch, check Dead unit is reported.
w = s.unit.WatchSubordinateUnits()
defer testing.AssertStop(c, w)
wc = testing.NewLaxStringsWatcherC(c, s.State, w)
wc.AssertChange(subUnits[0].Name())
wc.AssertNoChange()
// Remove the leftover, check no change.
err = subUnits[0].Remove()
c.Assert(err, IsNil)
wc.AssertNoChange()
}