feat: add script processor using Tengo (#428)

- Implement a new 'script' processor with 'tengo' as the only supported
  script engine.
- Add internal packages for translating asset proto value into
  map[string]interface{} and for updating asset proto value with the
  given map.

Author: sudo-suhas

.gitignore

@@ -32,3 +32,5 @@ meteor-plugin-*
 
 # build
 /dist
+
+.playground

docs/docs/reference/processors.md

@@ -28,4 +28,18 @@ processors:
 
 This processor will append Asset's Labels with value from given config.
 
-[More details](https://github.com/odpf/meteor/blob/main/plugins/processors/labels/README.md)
+[More details][labels-readme]
+
+## Script
+
+Script processor uses the user specified script to transform each asset emitted
+from the extractor. Currently, [Tengo][tengo] is the only supported script
+engine.
+
+[More details][script-readme]
+
+[labels-readme]: https://github.com/odpf/meteor/blob/main/plugins/processors/labels/README.md
+
+[script-readme]: https://github.com/odpf/meteor/blob/main/plugins/processors/script/README.md
+
+[tengo]: https://github.com/d5/tengo

go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/benbjohnson/clock v1.3.0 // indirect
 	github.com/blastrain/vitess-sqlparser v0.0.0-20201030050434-a139afbb1aba
 	github.com/cenkalti/backoff/v4 v4.1.2
+	github.com/d5/tengo/v2 v2.13.0
 	github.com/denisenkom/go-mssqldb v0.10.0
 	github.com/dnaeon/go-vcr/v2 v2.0.1
 	github.com/elastic/go-elasticsearch v0.0.0
@@ -31,7 +32,9 @@ require (
 	github.com/go-playground/validator/v10 v10.10.0
 	github.com/go-sql-driver/mysql v1.6.0
 	github.com/gocql/gocql v0.0.0-20210817081954-bc256bbb90de
+	github.com/google/go-cmp v0.5.8
 	github.com/google/go-github/v37 v37.0.0
+	github.com/gopherjs/gopherjs v0.0.0-20210503212227-fb464eba2686 // indirect
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
 	github.com/lib/pq v1.10.4
@@ -50,6 +53,7 @@ require (
 	github.com/prestodb/presto-go-client v0.0.0-20211201125635-ad28cec17d6c
 	github.com/schollz/progressbar/v3 v3.8.5
 	github.com/segmentio/kafka-go v0.4.17
+	github.com/sergi/go-diff v1.1.0 // indirect
 	github.com/sijms/go-ora/v2 v2.2.22
 	github.com/snowflakedb/gosnowflake v1.6.7
 	github.com/spf13/cast v1.5.0 // indirect
@@ -74,8 +78,3 @@ require (
 	gopkg.in/ini.v1 v1.66.6 // indirect
 	gopkg.in/yaml.v3 v3.0.1
 )
-
-require (
-	github.com/gopherjs/gopherjs v0.0.0-20210503212227-fb464eba2686 // indirect
-	github.com/sergi/go-diff v1.1.0 // indirect
-)

go.sum

@@ -501,6 +501,8 @@ github.com/d2g/dhcp4 v0.0.0-20170904100407-a1d1b6c41b1c/go.mod h1:Ct2BUK8SB0YC1S
 github.com/d2g/dhcp4client v1.0.0/go.mod h1:j0hNfjhrt2SxUOw55nL0ATM/z4Yt3t2Kd1mW34z5W5s=
 github.com/d2g/dhcp4server v0.0.0-20181031114812-7d4a0a7f59a5/go.mod h1:Eo87+Kg/IX2hfWJfwxMzLyuSZyxSoAug2nGa1G2QAi8=
 github.com/d2g/hardwareaddr v0.0.0-20190221164911-e7d9fbe030e4/go.mod h1:bMl4RjIciD2oAxI7DmWRx6gbeqrkoLqv3MV0vzNad+I=
+github.com/d5/tengo/v2 v2.13.0 h1:4pZ5mR4vjOejpp+PMeIMpjZdObK7iwWoLTpVyhT+0Jk=
+github.com/d5/tengo/v2 v2.13.0/go.mod h1:XRGjEs5I9jYIKTxly6HCF8oiiilk5E/RYXOZ5b0DZC8=
 github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964 h1:y5HC9v93H5EPKqaS1UYVg1uYah5Xf51mBfIoWehClUQ=
 github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964/go.mod h1:Xd9hchkHSWYkEqJwUGisez3G1QY8Ryz0sdWrLPMGjLk=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

plugins/internal/tengoutil/secure_script.go

@@ -0,0 +1,21 @@
+package tengoutil
+
+import (
+	"github.com/d5/tengo/v2"
+	"github.com/d5/tengo/v2/stdlib"
+)
+
+const (
+	maxAllocs = 5000
+	maxConsts = 500
+)
+
+func NewSecureScript(input []byte) *tengo.Script {
+	s := tengo.NewScript(input)
+
+	s.SetImports(stdlib.GetModuleMap(stdlib.AllModuleNames()...))
+	s.SetMaxAllocs(maxAllocs)
+	s.SetMaxConstObjects(maxConsts)
+
+	return s
+}

plugins/internal/tengoutil/secure_script_test.go

@@ -0,0 +1,36 @@
+//go:build plugins
+// +build plugins
+
+package tengoutil
+
+import (
+	"testing"
+
+	"github.com/MakeNowJust/heredoc"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewSecureScript(t *testing.T) {
+	t.Run("Allows import of builtin modules", func(t *testing.T) {
+		s := NewSecureScript(([]byte)(heredoc.Doc(`
+			math := import("math")
+			os := import("os")
+			text := import("text")
+			times := import("times")
+			rand := import("rand")
+			fmt := import("fmt")
+			json := import("json")
+			base64 := import("base64")
+			hex := import("hex")
+			enum := import("enum")
+		`)))
+		_, err := s.Compile()
+		assert.NoError(t, err)
+	})
+
+	t.Run("File import disallowed", func(t *testing.T) {
+		s := NewSecureScript(([]byte)(`sum := import("./testdata/sum")`))
+		_, err := s.Compile()
+		assert.ErrorContains(t, err, "Compile Error: module './testdata/sum' not found")
+	})
+}

plugins/internal/tengoutil/structmap/asset_wrapper.go

@@ -0,0 +1,59 @@
+package structmap
+
+import (
+	"fmt"
+
+	v1beta2 "github.com/odpf/meteor/models/odpf/assets/v1beta2"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/types/known/anypb"
+)
+
+type AssetWrapper struct {
+	A *v1beta2.Asset
+}
+
+func (w AssetWrapper) AsMap() (map[string]interface{}, error) {
+	v, err := AsMap(w.A)
+	if err != nil {
+		return nil, fmt.Errorf("structmap: asset as map: %w", err)
+	}
+
+	m, ok := v.(map[string]interface{})
+	if !ok {
+		return nil, fmt.Errorf("structmap: asset as map: unexpected type for asset map: %T", v)
+	}
+
+	return m, err
+}
+
+func (w *AssetWrapper) OverwriteWith(m map[string]interface{}) error {
+	dataMap, ok := m["data"].(map[string]interface{})
+	if !ok {
+		return fmt.Errorf("structmap: overwrite asset: unexpected type for asset data: %T", m["data"])
+	}
+
+	mt, err := protoregistry.GlobalTypes.FindMessageByName(w.A.Data.MessageName())
+	if err != nil {
+		return fmt.Errorf("structmap: overwrite asset: resolve type by full name %s: %w", w.A.Data.MessageName(), err)
+	}
+
+	msg := mt.New().Interface()
+	delete(dataMap, "@type")
+	if err := AsStruct(m["data"], &msg); err != nil {
+		return fmt.Errorf("structmap: overwrite asset: decode asset data: %w", err)
+	}
+
+	delete(m, "data")
+	if err := AsStruct(m, w.A); err != nil {
+		return fmt.Errorf("structmap: overwrite asset: decode asset: %w", err)
+	}
+
+	data, err := anypb.New(msg)
+	if err != nil {
+		return fmt.Errorf("structmap: overwrite asset: marshal data as any: %w", err)
+	}
+
+	w.A.Data = data
+
+	return nil
+}