Implement setting worker state

In order to perform maintenance, Worker should be in a proper state.
Administrator should set state to MAINTENANCE before taking action
and set it back to IDLE so it will return to the pool.

Change-Id: I44e2c64645e3643c16e8484c746ae4a233a6d232
Signed-off-by: Aleksander Mistewicz <a.mistewicz@samsung.com>
Reviewed-on: https://mcdsrvbld02.digital.local/review/49059
Reviewed-by: Maciej Wereski <m.wereski@partner.samsung.com>
Tested-by: Maciej Wereski <m.wereski@partner.samsung.com>

4 files changed, 76 insertions, 5 deletions

diff --git a/workers/error.go b/workers/error.go
index bd51509..0ebe8bc 100644
--- a/workers/error.go
+++ b/workers/error.go
@@ -33,4 +33,10 @@ var (
 	// ErrNotInMaintenance is returned when Deregister is called for a worker not in MAINTENANCE state.
 	// Only workers in MAINTENANCE state can be removed from the list.
 	ErrNotInMaintenance = errors.New("Worker is not in MAINTENANCE state")
+	// ErrWrongStateArgument is returned when SetState is called with incorrect state argument.
+	// Worker state can be changed by Admin to IDLE or MAINTENANCE only.
+	ErrWrongStateArgument = errors.New("Only state changes to IDLE and MAINTENANCE are allowed")
+	// ErrForbiddenStateChange is returned when transition from state, Worker is in,
+	// to state, SetState has been called with, is forbidden.
+	ErrForbiddenStateChange = errors.New("Invalid state transition was requested")
 )
diff --git a/workers/worker_list_test.go b/workers/worker_list_test.go
index 2800cbf..92ce1fa 100644
--- a/workers/worker_list_test.go
+++ b/workers/worker_list_test.go
@@ -205,5 +205,61 @@ var _ = Describe("WorkerList", func() {
 				}
 			})
 		})
+
+		Describe("SetState", func() {
+			It("should fail to SetState of nonexistent worker", func() {
+				uuid := randomUUID()
+				err := wl.SetState(uuid, MAINTENANCE)
+				Expect(err).To(Equal(ErrWorkerNotFound))
+			})
+
+			It("should work to SetState for valid transitions", func() {
+				validTransitions := [][]WorkerState{
+					{MAINTENANCE, IDLE},
+					{IDLE, MAINTENANCE},
+					{RUN, MAINTENANCE},
+					{FAIL, MAINTENANCE},
+				}
+				for _, transition := range validTransitions {
+					fromState, toState := transition[0], transition[1]
+					wl.workers[worker].State = fromState
+					err := wl.SetState(worker, toState)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(wl.workers[worker].State).To(Equal(toState))
+				}
+			})
+
+			It("should fail to SetState for invalid transitions", func() {
+				invalidTransitions := [][]WorkerState{
+					{RUN, IDLE},
+					{FAIL, IDLE},
+				}
+				for _, transition := range invalidTransitions {
+					fromState, toState := transition[0], transition[1]
+					wl.workers[worker].State = fromState
+					err := wl.SetState(worker, toState)
+					Expect(err).To(Equal(ErrForbiddenStateChange))
+					Expect(wl.workers[worker].State).To(Equal(fromState))
+				}
+			})
+
+			It("should fail to SetState for incorrect state argument", func() {
+				invalidArgument := [][]WorkerState{
+					{MAINTENANCE, RUN},
+					{MAINTENANCE, FAIL},
+					{IDLE, FAIL},
+					{IDLE, RUN},
+					{RUN, FAIL},
+					{FAIL, RUN},
+				}
+				for _, transition := range invalidArgument {
+					fromState, toState := transition[0], transition[1]
+					wl.workers[worker].State = fromState
+					err := wl.SetState(worker, toState)
+					Expect(err).To(Equal(ErrWrongStateArgument))
+					Expect(wl.workers[worker].State).To(Equal(fromState))
+				}
+			})
+		})
 	})
 })
diff --git a/workers/workers.go b/workers/workers.go
index ff21f09..b265f73 100644
--- a/workers/workers.go
+++ b/workers/workers.go
@@ -78,7 +78,20 @@ func (wl *WorkerList) SetFail(uuid WorkerUUID, reason string) error {
 
 // SetState is an implementation of SetState from Workers interface.
 func (wl *WorkerList) SetState(uuid WorkerUUID, state WorkerState) error {
-	return ErrNotImplemented
+	// Only state transitions to IDLE or MAINTENANCE are allowed.
+	if state != MAINTENANCE && state != IDLE {
+		return ErrWrongStateArgument
+	}
+	worker, ok := wl.workers[uuid]
+	if !ok {
+		return ErrWorkerNotFound
+	}
+	// State transitions to IDLE are allowed from MAINTENANCE state only.
+	if state == IDLE && worker.State != MAINTENANCE {
+		return ErrForbiddenStateChange
+	}
+	worker.State = state
+	return nil
 }
 
 // SetGroups is an implementation of SetGroups from Workers interface.
diff --git a/workers/workers_test.go b/workers/workers_test.go
index dc2fed5..8247544 100644
--- a/workers/workers_test.go
+++ b/workers/workers_test.go
@@ -38,10 +38,6 @@ var _ = Describe("WorkerList", func() {
 			groups Groups       = nil
 		)
 
-		By("SetState")
-		err = wl.SetState(uuid, MAINTENANCE)
-		Expect(err).To(Equal(ErrNotImplemented))
-
 		By("SetGroups")
 		err = wl.SetGroups(uuid, groups)
 		Expect(err).To(Equal(ErrNotImplemented))