Merge pull request #23 from spotify/rugvip/inv-store

inventory: added basic unused storage api

backend/inventory/go.mod

@@ -4,8 +4,6 @@ go 1.12
 
 require (
 	github.com/golang/protobuf v1.3.2
-	golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3 // indirect
-	golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135 // indirect
+	go.etcd.io/bbolt v1.3.3
 	google.golang.org/grpc v1.27.0
-	honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc // indirect
 )

backend/inventory/go.sum

@@ -11,6 +11,8 @@ github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+go.etcd.io/bbolt v1.3.3 h1:MUGmc65QhB3pIlaQ5bB4LwqSj6GIonVJXpZiaKNyaKk=
+go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -26,6 +28,7 @@ golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

backend/inventory/storage/storage.go

@@ -0,0 +1,66 @@
+package storage
+
+import (
+	"fmt"
+	"os"
+
+	"go.etcd.io/bbolt"
+)
+
+type Config struct {
+	Path string
+	Mode os.FileMode
+}
+
+type Storage struct {
+	db *bbolt.DB
+}
+
+func OpenStorage(config Config) (*Storage, error) {
+	if config.Path == "" {
+		config.Path = "inventory.db"
+	}
+	if config.Mode == 0 {
+		config.Mode = 0600
+	}
+	db, err := bbolt.Open(config.Path, config.Mode, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Storage{
+		db: db,
+	}, nil
+}
+
+func (s *Storage) Close() error {
+	return s.db.Close()
+}
+
+func (s *Storage) SetFact(entityUri, name, value string) error {
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		b, err := tx.CreateBucketIfNotExists([]byte(entityUri))
+		if err != nil {
+			return err
+		}
+		return b.Put([]byte(name), []byte(value))
+	})
+}
+
+func (s *Storage) GetFact(entityUri, name string) (string, error) {
+	var value string
+
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket([]byte(entityUri))
+		if b == nil {
+			return fmt.Errorf("bucket '%s' does not exist", entityUri)
+		}
+		value = string(b.Get([]byte(name)))
+		return nil
+	})
+	if err != nil {
+		return "", err
+	}
+
+	return value, nil
+}