web: add UI to adjust roles of existing nodes

pkg/instance/api.go

@@ -10,7 +10,8 @@ func (i *Instance) setupInstanceAPI() {
 	i.ForRole("instance", i.rootContext).AddEventListener(apitypes.EventTopicAPIMuxSetup, func(ev *roles.Event) {
 		svc := ev.Payload.Data["svc"].(*web.Service)
 		svc.Get("/api/v1/cluster", i.APIClusterInfo())
-		svc.Get("/api/v1/cluster/instance", i.APIInstanceInfo())
+		svc.Get("/api/v1/cluster/instance", i.APIInstanceGet())
+		svc.Put("/api/v1/cluster/instance", i.APIInstancePut())
 		svc.Post("/api/v1/cluster/roles/restart", i.APIClusterRoleRestart())
 	})
 }

pkg/instance/api_instance.go

@@ -74,7 +74,7 @@ type APIInstanceInfo struct {
 	InstanceIP         string `json:"instanceIP" required:"true"`
 }
 
-func (i *Instance) APIInstanceInfo() usecase.Interactor {
+func (i *Instance) APIInstanceGet() usecase.Interactor {
 	u := usecase.NewInteractor(func(ctx context.Context, input struct{}, output *APIInstanceInfo) error {
 		output.Version = extconfig.Version
 		output.BuildHash = extconfig.BuildHash
@@ -89,3 +89,32 @@ func (i *Instance) APIInstanceInfo() usecase.Interactor {
 	u.SetExpectedErrors(status.Internal)
 	return u
 }
+
+type APIInstancesPutInput struct {
+	Identifier string `query:"identifier" required:"true"`
+
+	Roles []string `json:"roles" required:"true"`
+}
+
+func (i *Instance) APIInstancePut() usecase.Interactor {
+	u := usecase.NewInteractor(func(ctx context.Context, input APIInstancesPutInput, output *struct{}) error {
+		_, err := i.kv.Put(
+			ctx,
+			i.kv.Key(
+				types.KeyInstance,
+				i.identifier,
+				types.KeyRoles,
+			).String(),
+			string(strings.Join(input.Roles, types.RoleSeparator)),
+		)
+		if err != nil {
+			return status.Wrap(err, status.Internal)
+		}
+		return nil
+	})
+	u.SetName("cluster.put_instance")
+	u.SetTitle("Instance")
+	u.SetTags("cluster/instances")
+	u.SetExpectedErrors(status.Internal)
+	return u
+}

pkg/instance/api_instance_test.go

@@ -14,7 +14,7 @@ func TestAPIInstanceInfo(t *testing.T) {
 	rootInst := instance.New()
 
 	var output instance.APIInstanceInfo
-	assert.NoError(t, rootInst.APIInstanceInfo().Interact(tests.Context(), struct{}{}, &output))
+	assert.NoError(t, rootInst.APIInstanceGet().Interact(tests.Context(), struct{}{}, &output))
 	assert.NotNil(t, output)
 	assert.Equal(t, output.Version, extconfig.Version)
 }

pkg/instance/instance.go

@@ -154,57 +154,11 @@ func (i *Instance) getRoles(ctx context.Context) []string {
 	roles := extconfig.Get().BootstrapRoles
 	if err == nil && len(rr.Kvs) > 0 {
 		roles = string(rr.Kvs[0].Value)
-		i.log.Info("roles configured for instance", zap.Strings("roles", strings.Split(roles, ";")))
+		i.log.Info("roles configured for instance", zap.Strings("roles", strings.Split(roles, types.RoleSeparator)))
 	} else {
-		i.log.Info("defaulting to bootstrap roles", zap.Strings("roles", strings.Split(roles, ";")))
+		i.log.Info("defaulting to bootstrap roles", zap.Strings("roles", strings.Split(roles, types.RoleSeparator)))
 	}
-	return strings.Split(roles, ";")
-}
-
-func (i *Instance) bootstrap(ctx context.Context) {
-	i.log.Debug("bootstrapping instance")
-	i.keepAliveInstanceInfo(ctx)
-	i.setupInstanceAPI()
-	rootInstance := i.ForRole("root", ctx)
-	for _, roleId := range i.getRoles(ctx) {
-		instanceRoles.WithLabelValues(roleId).Add(1)
-		rctx, cancel := context.WithCancelCause(i.rootContext)
-		rc := RoleContext{
-			RoleInstance:      i.ForRole(roleId, rctx),
-			ContextCancelFunc: cancel,
-		}
-		switch roleId {
-		case "etcd":
-			// Special handling
-			continue
-		default:
-			span := sentry.StartSpan(ctx, "gravity.instance.bootstrap.role")
-			span.SetTag("gravity.role", roleId)
-			rc.Role = roles.GetRole(roleId)(rc.RoleInstance)
-			span.Finish()
-		}
-		i.rolesM.Lock()
-		i.roles[roleId] = rc
-		i.rolesM.Unlock()
-	}
-	rootInstance.AddEventListener(types.EventTopicRoleRestart, i.eventRoleRestart)
-	rootInstance.DispatchEvent(
-		types.EventTopicInstanceBootstrapped,
-		roles.NewEvent(i.rootContext, map[string]interface{}{}),
-	)
-	i.checkFirstStart(ctx)
-	wg := sync.WaitGroup{}
-	for roleId := range i.roles {
-		wg.Add(1)
-		go i.startWatchRole(ctx, roleId, func() {
-			wg.Done()
-		})
-	}
-	go func() {
-		wg.Wait()
-		i.DispatchEvent(types.EventTopicRolesStarted, roles.NewEvent(ctx, map[string]interface{}{}))
-		sentry.TransactionFromContext(ctx).Finish()
-	}()
+	return strings.Split(roles, types.RoleSeparator)
 }
 
 func (i *Instance) eventRoleRestart(ev *roles.Event) {

pkg/instance/instance_bootstrap.go

@@ -0,0 +1,56 @@
+package instance
+
+import (
+	"context"
+	"sync"
+
+	"beryju.io/gravity/pkg/instance/types"
+	"beryju.io/gravity/pkg/roles"
+	"github.com/getsentry/sentry-go"
+)
+
+func (i *Instance) bootstrap(ctx context.Context) {
+	i.log.Debug("bootstrapping instance")
+	i.keepAliveInstanceInfo(ctx)
+	i.setupInstanceAPI()
+	rootInstance := i.ForRole("root", ctx)
+	for _, roleId := range i.getRoles(ctx) {
+		instanceRoles.WithLabelValues(roleId).Add(1)
+		rctx, cancel := context.WithCancelCause(i.rootContext)
+		rc := RoleContext{
+			RoleInstance:      i.ForRole(roleId, rctx),
+			ContextCancelFunc: cancel,
+		}
+		switch roleId {
+		case "etcd":
+			// Special handling
+			continue
+		default:
+			span := sentry.StartSpan(ctx, "gravity.instance.bootstrap.role")
+			span.SetTag("gravity.role", roleId)
+			rc.Role = roles.GetRole(roleId)(rc.RoleInstance)
+			span.Finish()
+		}
+		i.rolesM.Lock()
+		i.roles[roleId] = rc
+		i.rolesM.Unlock()
+	}
+	rootInstance.AddEventListener(types.EventTopicRoleRestart, i.eventRoleRestart)
+	rootInstance.DispatchEvent(
+		types.EventTopicInstanceBootstrapped,
+		roles.NewEvent(i.rootContext, map[string]interface{}{}),
+	)
+	i.checkFirstStart(ctx)
+	wg := sync.WaitGroup{}
+	for roleId := range i.roles {
+		wg.Add(1)
+		go i.startWatchRole(ctx, roleId, func() {
+			wg.Done()
+		})
+	}
+	go func() {
+		wg.Wait()
+		i.DispatchEvent(types.EventTopicRolesStarted, roles.NewEvent(ctx, map[string]interface{}{}))
+		sentry.TransactionFromContext(ctx).Finish()
+	}()
+}

pkg/instance/types/role.go

@@ -7,3 +7,5 @@ const (
 	KeyCluster   = "cluster"
 	KeyMigration = "migration"
 )
+
+const RoleSeparator = ";"

pkg/roles/etcd/api.go

@@ -50,9 +50,9 @@ func (r *Role) APIClusterMembers() usecase.Interactor {
 }
 
 type APIMemberJoinInput struct {
-	Peer       string `json:"peer" maxLength:"255"`
-	Roles      string `json:"roles"`
-	Identifier string `json:"identifier"`
+	Peer       string   `json:"peer" maxLength:"255"`
+	Roles      []string `json:"roles"`
+	Identifier string   `json:"identifier"`
 }
 type APIMemberJoinOutput struct {
 	EtcdInitialCluster string `json:"etcdInitialCluster"`
@@ -80,11 +80,10 @@ func (r *Role) APIClusterJoin() usecase.Interactor {
 		))
 
 		// Pre-configure roles for new node
-		roles := strings.Split(input.Roles, ",")
-		if input.Roles == "" {
-			roles = strings.Split(extconfig.Get().BootstrapRoles, ",")
+		if len(input.Roles) == 0 {
+			input.Roles = strings.Split(extconfig.Get().BootstrapRoles, ",")
 			// If we're copying our roles, exclude backup
-			roles = slices.DeleteFunc(roles, func(role string) bool {
+			input.Roles = slices.DeleteFunc(input.Roles, func(role string) bool {
 				return role == "backup"
 			})
 		}
@@ -95,7 +94,7 @@ func (r *Role) APIClusterJoin() usecase.Interactor {
 				input.Identifier,
 				types.KeyRoles,
 			).String(),
-			strings.Join(roles, ","),
+			strings.Join(input.Roles, ","),
 		)
 		if err != nil {
 			r.log.Warn("failed to put roles for node", zap.Error(err))