pkg: add plugable storage broker drivers

cmd/revad/main.go

@@ -14,6 +14,7 @@ import (
 	"github.com/cernbox/reva/pkg/log"
 
 	_ "github.com/cernbox/reva/cmd/revad/svcs/httpsvcs/loader"
+	_ "github.com/cernbox/reva/pkg/storage/broker/loader"
 	_ "github.com/cernbox/reva/pkg/storage/fs/loader"
 
 	"github.com/cernbox/reva/cmd/revad/config"

cmd/revad/revad.toml

@@ -57,7 +57,7 @@ driver = "demo"
 [grpc.services.storagebrokersvc]
 driver = "static"
 
-[grpc.services.storagebrokersvc.static.rules]
+[grpc.services.storagebrokersvc.drivers.static.rules]
 "/" = "localhost:9999"
 "123e4567-e89b-12d3-a456-426655440000" = "localhost:9999"
 

cmd/revad/svcs/grpcsvcs/storagebrokersvc/storagebrokersvc.go

@@ -10,7 +10,7 @@ import (
 	"github.com/cernbox/reva/pkg/err"
 	"github.com/cernbox/reva/pkg/log"
 	"github.com/cernbox/reva/pkg/storage"
-	"github.com/cernbox/reva/pkg/storage/broker/static"
+	"github.com/cernbox/reva/pkg/storage/broker/registry"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -22,8 +22,8 @@ type service struct {
 }
 
 type config struct {
-	Driver string                 `mapstructure:"driver"`
-	Static map[string]interface{} `mapstructure:"static"`
+	Driver  string                            `mapstructure:"driver"`
+	Drivers map[string]map[string]interface{} `mapstructure:"drivers"`
 }
 
 // New creates a new StorageBrokerService
@@ -55,12 +55,10 @@ func parseConfig(m map[string]interface{}) (*config, error) {
 }
 
 func getBroker(c *config) (storage.Broker, error) {
-	switch c.Driver {
-	case "static":
-		return static.New(c.Static)
-	default:
-		return nil, fmt.Errorf("driver not found: %s", c.Driver)
+	if f, ok := registry.NewFuncs[c.Driver]; ok {
+		return f(c.Drivers[c.Driver])
 	}
+	return nil, fmt.Errorf("driver not found: %s", c.Driver)
 }
 
 func (s *service) Discover(ctx context.Context, req *storagebrokerv0alphapb.DiscoverRequest) (*storagebrokerv0alphapb.DiscoverResponse, error) {

pkg/storage/broker/loader/loader.go

@@ -0,0 +1,7 @@
+package loader
+
+import (
+	// Load core storage broker drivers.
+	_ "github.com/cernbox/reva/pkg/storage/broker/static"
+	// Add your own here
+)

pkg/storage/broker/registry/registry.go

@@ -0,0 +1,16 @@
+package registry
+
+import "github.com/cernbox/reva/pkg/storage"
+
+// NewFunc is the function that storage broker implementations
+// should register at init time.
+type NewFunc func(map[string]interface{}) (storage.Broker, error)
+
+// NewFuncs is a map containing all the registered storage backends.
+var NewFuncs = map[string]NewFunc{}
+
+// Register registers a new storage broker new function.
+// Not safe for concurrent use. Safe for use from package init.
+func Register(name string, f NewFunc) {
+	NewFuncs[name] = f
+}

pkg/storage/broker/static/static.go

@@ -5,11 +5,16 @@ import (
 	"strings"
 
 	"github.com/cernbox/reva/pkg/log"
+	"github.com/cernbox/reva/pkg/storage/broker/registry"
 
 	"github.com/cernbox/reva/pkg/storage"
 	"github.com/mitchellh/mapstructure"
 )
 
+func init() {
+	registry.Register("static", New)
+}
+
 var logger = log.New("static")
 
 type broker struct {