Merge pull request #32 from gateway-fm/optional_path

Optional Path implementation

discovery/consul_discovery.go

@@ -2,7 +2,6 @@ package discovery
 
 import (
 	"fmt"
-
 	consul "github.com/hashicorp/consul/api"
 
 	"github.com/gateway-fm/scriptorium/logger"
@@ -15,16 +14,18 @@ import (
 type ConsulDiscovery struct {
 	client    *consul.Client
 	transport TransportProtocol
+	opts      *DiscoveryOpts
 }
 
 // NewConsulDiscovery create new Consul-driven
 // service Discovery
-func NewConsulDiscovery(transport TransportProtocol, addr ...string) (IServiceDiscovery, error) {
+func NewConsulDiscovery(transport TransportProtocol, opts *DiscoveryOpts, addr ...string) (IServiceDiscovery, error) {
 	if len(addr) != 1 {
 		return nil, ErrInvalidArgumentsLength{length: len(addr), driver: DriverConsul}
 	}
 
 	config := consul.DefaultConfig()
+
 	if addr[0] != "" {
 		config.Address = addr[0]
 	}
@@ -34,7 +35,22 @@ func NewConsulDiscovery(transport TransportProtocol, addr ...string) (IServiceDi
 		return nil, fmt.Errorf("connect to consul discovery: %w", err)
 	}
 
-	return &ConsulDiscovery{client: c, transport: transport}, nil
+	if opts == nil {
+		opts = NilDiscoveryOptions()
+	}
+	if opts.isOptional {
+		if opts.optionalPath == "" {
+			return nil, ErrEmptyOptionalPath
+		}
+	}
+
+	consulDiscovery := &ConsulDiscovery{
+		client:    c,
+		transport: transport,
+		opts:      opts,
+	}
+
+	return consulDiscovery, nil
 }
 
 // Discover and return list of the active
@@ -65,12 +81,18 @@ func (d *ConsulDiscovery) createNodesFromServices(consulServices []*consul.Servi
 // instance from consul service
 func (d *ConsulDiscovery) createServiceFromConsul(srv *consul.ServiceEntry) service.IService {
 	addr := d.transport.FormatAddress(srv.Service.Address)
+	addr = fmt.Sprintf("%s:%d", addr, srv.Service.Port)
+
+	if d.opts.isOptional && d.opts.optionalPath != "" {
+		addr = AddEndOrRemoveFirstSlashIfNeeded(addr) + AddEndOrRemoveFirstSlashIfNeeded(d.opts.optionalPath)
+	}
+
 	logger.Log().Debug(fmt.Sprintf("discovered new service: %s", addr))
 
 	tagsMap := make(map[string]struct{})
 	for _, t := range srv.Service.Tags {
 		tagsMap[t] = struct{}{}
 	}
 
-	return service.NewService(fmt.Sprintf("%s:%d", addr, srv.Service.Port), srv.Service.ID, tagsMap)
+	return service.NewService(addr, srv.Service.ID, tagsMap)
 }

discovery/discovery.go

@@ -1,6 +1,7 @@
 package discovery
 
 import (
+	"errors"
 	"github.com/gateway-fm/service-pool/service"
 )
 
@@ -10,9 +11,13 @@ type IServiceDiscovery interface {
 	// Discover service by given name
 	Discover(service string) ([]service.IService, error)
 }
+type DiscoveryOpts struct {
+	isOptional   bool
+	optionalPath string
+}
 
 // Creator is discovery factory function
-type Creator func(TransportProtocol, ...string) (IServiceDiscovery, error)
+type Creator func(TransportProtocol, *DiscoveryOpts, ...string) (IServiceDiscovery, error)
 
 // ParseDiscoveryDriver create new addresses discovery
 // Creator based on given discovery driver
@@ -26,3 +31,17 @@ func ParseDiscoveryDriver(driver Driver) (Creator, error) {
 		return nil, ErrUnsupportedDriver{driver.String()}
 	}
 }
+
+func NewDiscoveryOpts(isPathOptional bool, optionalPath string) *DiscoveryOpts {
+	return &DiscoveryOpts{
+		isOptional:   isPathOptional,
+		optionalPath: optionalPath,
+	}
+}
+
+// NilDiscoveryOptions to prevent nil pointers if there are no options
+func NilDiscoveryOptions() *DiscoveryOpts {
+	return &DiscoveryOpts{}
+}
+
+var ErrEmptyOptionalPath = errors.New("optional path is empty")

discovery/manual_discovery.go

@@ -9,12 +9,14 @@ import (
 type ManualDiscovery struct {
 	addresses []string
 	transport TransportProtocol
+	opts      *DiscoveryOpts
 }
 
 // NewManualDiscovery create new manual
 // NodesDiscovery with given addresses
-func NewManualDiscovery(transport TransportProtocol, addrs ...string) (IServiceDiscovery, error) {
-	return &ManualDiscovery{addresses: addrs, transport: transport}, nil
+func NewManualDiscovery(transport TransportProtocol, opts *DiscoveryOpts, addrs ...string) (IServiceDiscovery, error) {
+	opts = NilDiscoveryOptions()
+	return &ManualDiscovery{addresses: addrs, opts: opts, transport: transport}, nil
 }
 
 // Discover is discover and return list of the active

discovery/util.go

@@ -0,0 +1,19 @@
+package discovery
+
+import "fmt"
+
+func AddEndOrRemoveFirstSlashIfNeeded(addr string) string {
+	b := []byte(addr)
+	if len(b) == 0 {
+		return ""
+	}
+	lastByte := b[len(b)-1]
+	if lastByte != '/' {
+		addr = fmt.Sprintf("%s/", addr)
+	}
+	if b[0] == '/' {
+		b = append(b[1:])
+		addr = string(b)
+	}
+	return addr
+}

testutils.go

@@ -47,7 +47,7 @@ func newHealthyService(addr string) service.IService {
 }
 
 func newServicesPool(discoveryInterval time.Duration, hcInterval time.Duration, mutationFunc func(srv service.IService) (service.IService, error)) IServicesPool {
-	manualDisc, _ := discovery.NewManualDiscovery(discovery.TransportHttp, "localhost")
+	manualDisc, _ := discovery.NewManualDiscovery(discovery.TransportHttp, nil, "localhost")
 
 	opts := &ServicesPoolsOpts{
 		Name:              "TestServicePool",