// RunOnce runs a unit agent once.
func (a *UnitAgent) RunOnce(st *state.State, e AgentState) error {
unit := e.(*state.Unit)
tasks := []task{
uniter.NewUniter(st, unit.Name(), a.Conf.DataDir),
NewUpgrader(st, unit, a.Conf.DataDir),
}
if unit.IsPrincipal() {
tasks = append(tasks,
newDeployer(st, unit.WatchSubordinateUnits(), a.Conf.DataDir))
}
return runTasks(a.tomb.Dying(), tasks...)
}
// StateWorkers returns a worker that runs the unit agent workers.
func (a *UnitAgent) StateWorkers() (worker.Worker, error) {
st, entity, err := openState(a.Conf.Conf, a)
if err != nil {
return nil, err
}
unit := entity.(*state.Unit)
dataDir := a.Conf.DataDir
runner := worker.NewRunner(allFatal, moreImportant)
runner.StartWorker("uniter", func() (worker.Worker, error) {
return uniter.NewUniter(st, unit.Name(), dataDir), nil
})
return newCloseWorker(runner, st), nil
}
// Workers returns a worker that runs the unit agent workers.
func (a *UnitAgent) Workers() (worker.Worker, error) {
st, entity, err := openState(a.Conf.Conf, a)
if err != nil {
return nil, err
}
if err := EnsureAPIInfo(a.Conf.Conf, st, entity); err != nil {
// We suppress this error, because it is probably more interesting
// to see other failures, but we log it, in case it is a root cause
agentLogger.Warningf("error while calling EnsureAPIInfo: %v", err)
}
unit := entity.(*state.Unit)
dataDir := a.Conf.DataDir
runner := worker.NewRunner(allFatal, moreImportant)
runner.StartWorker("upgrader", func() (worker.Worker, error) {
return NewUpgrader(st, unit, dataDir), nil
})
runner.StartWorker("uniter", func() (worker.Worker, error) {
return uniter.NewUniter(st, unit.Name(), dataDir), nil
})
return newCloseWorker(runner, st), nil
}
func (s startUniter) step(c *C, ctx *context) {
if ctx.uniter != nil {
panic("don't start two uniters!")
}
ctx.uniter = uniter.NewUniter(ctx.st, "u/0", ctx.dataDir)
}