Merge pull request #33 from getamis/feature/TFU-02-03-remove-validators

Implement TFU-02-03 Remove validators

container/blockchain.go

@@ -33,6 +33,7 @@ import (
 
 type Blockchain interface {
 	AddValidators(numOfValidators int) ([]Ethereum, error)
+	RemoveValidators(candidates []Ethereum, t time.Duration) error
 	EnsureConsensusWorking(geths []Ethereum, t time.Duration) error
 	Start(bool) error
 	Stop(bool) error
@@ -127,6 +128,32 @@ func (bc *blockchain) EnsureConsensusWorking(geths []Ethereum, t time.Duration)
 	return err
 }
 
+func (bc *blockchain) RemoveValidators(candidates []Ethereum, processingTime time.Duration) error {
+	var newValidators []Ethereum
+
+	for _, v := range bc.validators {
+		istClient := v.NewIstanbulClient()
+		isFound := false
+		for _, c := range candidates {
+			if err := istClient.ProposeValidator(context.Background(), c.Address(), false); err != nil {
+				return err
+			}
+			if v.ContainerID() == c.ContainerID() {
+				isFound = true
+			}
+		}
+		if !isFound {
+			newValidators = append(newValidators, v)
+		}
+	}
+
+	// FIXME: It is not good way to wait validator vote out candidates
+	<-time.After(processingTime)
+	bc.validators = newValidators
+
+	return bc.stop(candidates, false)
+}
+
 func (bc *blockchain) Start(strong bool) error {
 	if err := bc.start(bc.validators); err != nil {
 		return err
@@ -135,12 +162,7 @@ func (bc *blockchain) Start(strong bool) error {
 }
 
 func (bc *blockchain) Stop(force bool) error {
-	for _, v := range bc.validators {
-		if err := v.Stop(); err != nil && !force {
-			return err
-		}
-	}
-	return nil
+	return bc.stop(bc.validators, force)
 }
 
 func (bc *blockchain) Finalize() {
@@ -260,9 +282,9 @@ func (bc *blockchain) start(validators []Ethereum) error {
 	return nil
 }
 
-func (bc *blockchain) stop(validators []Ethereum) error {
+func (bc *blockchain) stop(validators []Ethereum, force bool) error {
 	for _, v := range validators {
-		if err := v.Stop(); err != nil {
+		if err := v.Stop(); err != nil && !force {
 			return err
 		}
 	}

tests/dynamic_test.go

@@ -19,6 +19,7 @@ package tests
 import (
 	"context"
 	"time"
+	"math"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -47,7 +48,7 @@ var _ = Describe("Dynamic validators addition/removal testing", func() {
 	It("TFS-02-01 Add validators", func() {
 		testValidators := 3
 
-		By("Ensure that numbers of validator is equal than $numberOfValidators", func() {
+		By("Ensure that numbers of validator is equal to $numberOfValidators", func() {
 			for _, v := range blockchain.Validators() {
 				client := v.NewIstanbulClient()
 				validators, err := client.GetValidators(context.Background(), nil)
@@ -69,4 +70,48 @@ var _ = Describe("Dynamic validators addition/removal testing", func() {
 			Expect(len(validators)).Should(BeNumerically("==", numberOfValidators+testValidators))
 		}
 	})
+
+	It("TFS-02-03 Remove validators", func() {
+		numOfCandidates := 3
+
+		By("Ensure that numbers of validator is equal to $numberOfValidators", func() {
+			for _, v := range blockchain.Validators() {
+				client := v.NewIstanbulClient()
+				validators, err := client.GetValidators(context.Background(), nil)
+				Expect(err).Should(BeNil())
+				Expect(len(validators)).Should(BeNumerically("==", numberOfValidators))
+			}
+		})
+
+		_, err := blockchain.AddValidators(numOfCandidates)
+		Expect(err).Should(BeNil())
+
+		By("Ensure that consensus is working in 50 seconds", func() {
+			Expect(blockchain.EnsureConsensusWorking(blockchain.Validators(), 50*time.Second)).Should(BeNil())
+		})
+		for _, v := range blockchain.Validators() {
+			client := v.NewIstanbulClient()
+			validators, err := client.GetValidators(context.Background(), nil)
+			Expect(err).Should(BeNil())
+			Expect(len(validators)).Should(BeNumerically("==", numberOfValidators+numOfCandidates))
+		}
+
+		// remove validators [1,2,3]
+		removalCandidates := blockchain.Validators()[:numOfCandidates]
+		processingTime := time.Duration(math.Pow(2, float64(len(removalCandidates)))*7) * time.Second
+		Expect(blockchain.RemoveValidators(removalCandidates, processingTime)).Should(BeNil())
+		By("Ensure that consensus is working in 20 seconds", func() {
+			Expect(blockchain.EnsureConsensusWorking(blockchain.Validators(), 20*time.Second)).Should(BeNil())
+		})
+
+		for _, v := range blockchain.Validators() {
+			client := v.NewIstanbulClient()
+			validators, err := client.GetValidators(context.Background(), nil)
+			Expect(err).Should(BeNil())
+			Expect(len(validators)).Should(BeNumerically("==", numberOfValidators))
+		}
+		By("Ensure that consensus is working in 30 seconds", func() {
+			Expect(blockchain.EnsureConsensusWorking(blockchain.Validators(), 30*time.Second)).Should(BeNil())
+		})
+	})
 })