Add stream fields to each dataset

During the generation of the datasets, a stream.yml file is created with the stream fields inside. These are required for each dataset.

dev/generator/main.go

@@ -11,6 +11,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"path"
 	"path/filepath"
 
 	"github.com/magefile/mage/sh"
@@ -25,6 +26,20 @@ var (
 
 const (
 	packageDirName = "package"
+	streamFields   = `
+- name: stream.type
+  type: constant_keyword
+  description: >
+    Stream type
+- name: stream.dataset
+  type: constant_keyword
+  description: >
+    Stream dataset.
+- name: stream.namespace
+  type: constant_keyword
+  description: >
+    Stream namespace.
+`
 )
 
 func main() {
@@ -122,6 +137,25 @@ func buildPackage(packagesBasePath string, p util.Package) error {
 
 	p.BasePath = filepath.Join(currentPath, packagesBasePath, p.GetPath())
 
+	datasets, err := p.GetDatasets()
+	if err != nil {
+		return err
+	}
+
+	// Add stream.yml to all dataset with the basic stream fields
+	for _, dataset := range datasets {
+		dirPath := path.Join(p.BasePath, "dataset", dataset, "fields")
+		err := os.MkdirAll(dirPath, 0755)
+		if err != nil {
+			return err
+		}
+
+		err = ioutil.WriteFile(path.Join(dirPath, "stream.yml"), []byte(streamFields), 0644)
+		if err != nil {
+			return err
+		}
+	}
+
 	err = p.LoadAssets(p.GetPath())
 	if err != nil {
 		return err