Remove scheme id from client CLI and take it from chain info (#840)

* remove scheme id from client CLI and take it from chain info

client/client.go

@@ -7,8 +7,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/drand/drand/common/scheme"
-
 	"github.com/drand/drand/chain"
 	"github.com/drand/drand/log"
 	"github.com/drand/drand/metrics"
@@ -20,12 +18,9 @@ const clientStartupTimeoutDefault = time.Second * 5
 
 // New Creates a client with specified configuration.
 func New(options ...Option) (Client, error) {
-	sch, _ := scheme.GetSchemeByIDWithDefault("")
-
 	cfg := clientConfig{
 		cacheSize: 32,
 		log:       log.DefaultLogger(),
-		scheme:    sch,
 	}
 
 	for _, opt := range options {
@@ -65,6 +60,11 @@ func makeClient(cfg *clientConfig) (Client, error) {
 		return nil, err
 	}
 
+	// try to populate chain info
+	if err := cfg.tryPopulateInfo(cfg.clients...); err != nil {
+		return nil, err
+	}
+
 	// provision watcher client
 	var wc Client
 	if cfg.watcher != nil {
@@ -83,7 +83,8 @@ func makeClient(cfg *clientConfig) (Client, error) {
 
 	verifiers := make([]Client, 0, len(cfg.clients))
 	for _, source := range cfg.clients {
-		opts := Opts{scheme: cfg.scheme, strict: cfg.fullVerify}
+		opts := Opts{scheme: cfg.chainInfo.Scheme, strict: cfg.fullVerify}
+
 		nv := newVerifyingClient(source, cfg.previousResult, opts)
 		verifiers = append(verifiers, nv)
 		if source == wc {
@@ -133,9 +134,10 @@ func makeOptimizingClient(cfg *clientConfig, verifiers []Client, watcher Client,
 }
 
 func makeWatcherClient(cfg *clientConfig, cache Cache) (Client, error) {
-	if err := cfg.tryPopulateInfo(cfg.clients...); err != nil {
-		return nil, err
+	if cfg.chainInfo == nil {
+		return nil, fmt.Errorf("chain info cannot be nil")
 	}
+
 	w, err := cfg.watcher(cfg.chainInfo, cache)
 	if err != nil {
 		return nil, err
@@ -149,9 +151,6 @@ func attachMetrics(cfg *clientConfig, c Client) (Client, error) {
 		if err := metrics.RegisterClientMetrics(cfg.prometheus); err != nil {
 			return nil, err
 		}
-		if err := cfg.tryPopulateInfo(c); err != nil {
-			return nil, err
-		}
 		return newWatchLatencyMetricClient(c, cfg.chainInfo), nil
 	}
 	return c, nil
@@ -174,8 +173,6 @@ type clientConfig struct {
 	fullVerify bool
 	// insecure indicates the root of trust does not need to be present.
 	insecure bool
-	// scheme holds a set of values the client will use to act in specific ways, regarding signature verification, etc
-	scheme scheme.Scheme
 	// cache size - how large of a cache to keep locally.
 	cacheSize int
 	// customized client log.
@@ -227,20 +224,6 @@ func Insecurely() Option {
 	}
 }
 
-// WithSchemeID allows user to set a scheme using its ID. The scheme
-// is used to customize some behaviors inside the client
-func WithSchemeID(schID string) Option {
-	return func(cfg *clientConfig) error {
-		sch, err := scheme.GetSchemeByIDWithDefault(schID)
-		if err != nil {
-			return fmt.Errorf("scheme is not valid")
-		}
-
-		cfg.scheme = sch
-		return nil
-	}
-}
-
 // WithCacheSize specifies how large of a cache of randomness values should be
 // kept locally. Default 32
 func WithCacheSize(size int) Option {

client/client_test.go

@@ -30,7 +30,11 @@ func TestClientConstraints(t *testing.T) {
 		t.Fatal("Client needs root of trust unless insecure specified explicitly")
 	}
 
-	if _, e := client.New(client.From(client.MockClientWithResults(0, 5)), client.Insecurely()); e != nil {
+	c := client.MockClientWithResults(0, 5)
+	// As we will run is insecurely, we will set chain info so client can fetch it
+	c.OptionalInfo = fakeChainInfo()
+
+	if _, e := client.New(client.From(c), client.Insecurely()); e != nil {
 		t.Fatal(e)
 	}
 }
@@ -48,7 +52,6 @@ func TestClientMultiple(t *testing.T) {
 	var e error
 	c, e = client.New(
 		client.From(http.ForURLs([]string{"http://" + addr1, "http://" + addr2}, chainInfo.Hash())...),
-		client.WithSchemeID(sch.ID),
 		client.WithChainHash(chainInfo.Hash()))
 
 	if e != nil {
@@ -93,7 +96,6 @@ func TestClientCache(t *testing.T) {
 	var c client.Client
 	var e error
 	c, e = client.New(client.From(http.ForURLs([]string{"http://" + addr1}, chainInfo.Hash())...),
-		client.WithSchemeID(sch.ID),
 		client.WithChainHash(chainInfo.Hash()), client.WithCacheSize(1))
 
 	if e != nil {
@@ -125,7 +127,6 @@ func TestClientWithoutCache(t *testing.T) {
 	var e error
 	c, e = client.New(
 		client.From(http.ForURLs([]string{"http://" + addr1}, chainInfo.Hash())...),
-		client.WithSchemeID(sch.ID),
 		client.WithChainHash(chainInfo.Hash()),
 		client.WithCacheSize(0))
 
@@ -162,7 +163,6 @@ func TestClientWithWatcher(t *testing.T) {
 	var err error
 	c, err = client.New(
 		client.WithChainInfo(info),
-		client.WithSchemeID(sch.ID),
 		client.WithWatcher(watcherCtor),
 	)
 
@@ -250,7 +250,6 @@ func TestClientAutoWatch(t *testing.T) {
 		client.From(client.MockClientWithInfo(chainInfo)),
 		client.WithChainHash(chainInfo.Hash()),
 		client.WithWatcher(watcherCtor),
-		client.WithSchemeID(sch.ID),
 		client.WithAutoWatch(),
 	)
 
@@ -314,7 +313,6 @@ func TestClientAutoWatchRetry(t *testing.T) {
 		client.WithAutoWatch(),
 		client.WithAutoWatchRetry(time.Second),
 		client.WithCacheSize(len(results)),
-		client.WithSchemeID(sch.ID),
 	)
 
 	if err != nil {

client/mock_test.go

@@ -13,9 +13,10 @@ import (
 // MockClient provide a mocked client interface
 type MockClient struct {
 	sync.Mutex
-	WatchCh chan Result
-	WatchF  func(context.Context) <-chan Result
-	Results []mock.Result
+	OptionalInfo *chain.Info
+	WatchCh      chan Result
+	WatchF       func(context.Context) <-chan Result
+	Results      []mock.Result
 	// Delay causes results to be delivered after this period of time has
 	// passed. Note that if the context is canceled a result is still consumed
 	// from Results.
@@ -83,6 +84,9 @@ func (m *MockClient) Watch(ctx context.Context) <-chan Result {
 }
 
 func (m *MockClient) Info(ctx context.Context) (*chain.Info, error) {
+	if m.OptionalInfo != nil {
+		return m.OptionalInfo, nil
+	}
 	return nil, errors.New("not supported (mock client info)")
 }
 

client/utils_test.go

@@ -6,13 +6,17 @@ import (
 	"testing"
 	"time"
 
+	"github.com/drand/drand/common/scheme"
+
 	"github.com/drand/drand/chain"
 	"github.com/drand/drand/test"
 )
 
 // fakeChainInfo creates a chain info object for use in tests.
 func fakeChainInfo() *chain.Info {
+	sch := scheme.GetSchemeFromEnv()
 	return &chain.Info{
+		Scheme:      sch,
 		Period:      time.Second,
 		GenesisTime: time.Now().Unix(),
 		PublicKey:   test.GenerateIDs(1)[0].Public.Key,

client/verify_test.go

@@ -14,7 +14,7 @@ func mockClientWithVerifiableResults(n int) (client.Client, []mock.Result, error
 	sch := scheme.GetSchemeFromEnv()
 
 	info, results := mock.VerifiableResults(n, sch)
-	mc := client.MockClient{Results: results, StrictRounds: true}
+	mc := client.MockClient{Results: results, StrictRounds: true, OptionalInfo: info}
 
 	var c client.Client
 	var err error
@@ -24,7 +24,6 @@ func mockClientWithVerifiableResults(n int) (client.Client, []mock.Result, error
 		client.WithChainInfo(info),
 		client.WithVerifiedResult(&results[0]),
 		client.WithFullChainVerification(),
-		client.WithSchemeID(sch.ID),
 	)
 
 	if err != nil {

cmd/client/lib/cli.go

@@ -11,8 +11,6 @@ import (
 	"path"
 	"strings"
 
-	"github.com/drand/drand/common/scheme"
-
 	"github.com/BurntSushi/toml"
 	"github.com/drand/drand/chain"
 	"github.com/drand/drand/client"
@@ -80,13 +78,6 @@ var (
 		Usage: "Local (host:)port for constructed libp2p host to listen on",
 	}
 
-	// TypeFlag indicates a set of values drand will use to configure the randomness generation process
-	SchemeFlag = &cli.StringFlag{
-		Name:  "scheme",
-		Usage: "Indicates a set of values drand will use to configure the randomness generation process",
-		Value: scheme.DefaultSchemeID,
-	}
-
 	// JsonFlag is the CLI flag for enabling JSON output for logger
 	JSONFlag = &cli.BoolFlag{
 		Name:  "json",
@@ -105,7 +96,6 @@ var ClientFlags = []cli.Flag{
 	RelayFlag,
 	PortFlag,
 	JSONFlag,
-	SchemeFlag,
 }
 
 // Create builds a client, and can be invoked from a cli action supplied
@@ -152,13 +142,6 @@ func Create(c *cli.Context, withInstrumentation bool, opts ...client.Option) (cl
 		opts = append(opts, client.Insecurely())
 	}
 
-	schemeFound, err := scheme.GetSchemeByIDWithDefault(c.String(SchemeFlag.Name))
-	if err != nil {
-		return nil, fmt.Errorf("scheme %s given is invalid", c.String(SchemeFlag.Name))
-	}
-
-	opts = append(opts, client.WithSchemeID(schemeFound.ID))
-
 	clients = append(clients, buildHTTPClients(c, &info, hash, withInstrumentation)...)
 
 	gopt, err := buildGossipClient(c)

cmd/client/lib/cli_test.go

@@ -58,36 +58,36 @@ func TestClientLib(t *testing.T) {
 	go grpcLis.Start()
 	defer grpcLis.Stop(context.Background())
 
-	args := []string{"mock-client", "--url", "http://" + addr, "--grpc-connect", grpcLis.Addr(), "--insecure", "--scheme", sch.ID}
+	args := []string{"mock-client", "--url", "http://" + addr, "--grpc-connect", grpcLis.Addr(), "--insecure"}
 
 	fmt.Printf("%+v", args)
 	err = run(args)
 	if err != nil {
 		t.Fatal("GRPC should work", err)
 	}
 
-	args = []string{"mock-client", "--url", "https://" + addr, "--scheme", sch.ID}
+	args = []string{"mock-client", "--url", "https://" + addr}
 
 	err = run(args)
 	if err == nil {
 		t.Fatal("http needs insecure or hash", err)
 	}
 
-	args = []string{"mock-client", "--url", "http://" + addr, "--hash", hex.EncodeToString(info.Hash()), "--scheme", sch.ID}
+	args = []string{"mock-client", "--url", "http://" + addr, "--hash", hex.EncodeToString(info.Hash())}
 
 	err = run(args)
 	if err != nil {
 		t.Fatal("http should construct", err)
 	}
 
-	args = []string{"mock-client", "--relay", fakeGossipRelayAddr, "--scheme", sch.ID}
+	args = []string{"mock-client", "--relay", fakeGossipRelayAddr}
 
 	err = run(args)
 	if err == nil {
 		t.Fatal("relays need URL or hash", err)
 	}
 
-	args = []string{"mock-client", "--relay", fakeGossipRelayAddr, "--hash", hex.EncodeToString(info.Hash()), "--scheme", sch.ID}
+	args = []string{"mock-client", "--relay", fakeGossipRelayAddr, "--hash", hex.EncodeToString(info.Hash())}
 
 	err = run(args)
 	if err != nil {