Merge pull request #28 from GauntletWizard/extvar

Add a flag for extvars

cmd/root.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/golang/glog"
 	"github.com/spf13/cobra"
@@ -21,13 +22,15 @@ import (
 )
 
 const (
-	flagJpath = "jpath"
+	flagJpath  = "jpath"
+	flagExtVar = "extVar"
 )
 
 var clientConfig clientcmd.ClientConfig
 
 func init() {
 	RootCmd.PersistentFlags().StringP(flagJpath, "J", "", "Additional jsonnet library search path")
+	RootCmd.PersistentFlags().StringSliceP(flagExtVar, "V", nil, "Values of external variables")
 
 	// The "usual" clientcmd/kubectl flags
 	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
@@ -76,6 +79,18 @@ func JsonnetVM(cmd *cobra.Command) (*jsonnet.VM, error) {
 		vm.JpathAdd(p)
 	}
 
+	extvars, err := flags.GetStringSlice(flagExtVar)
+	if err != nil {
+		return nil, err
+	}
+	for _, extvar := range extvars {
+		kv := strings.SplitN(extvar, "=", 2)
+		if len(kv) != 2 {
+			return nil, fmt.Errorf("Failed to parse extvar: missing '=' in %s", extvar)
+		}
+		vm.ExtVar(kv[0], kv[1])
+	}
+
 	return vm, nil
 }
 

cmd/show_test.go

@@ -45,6 +45,7 @@ func TestShow(t *testing.T) {
   "bool": true,
   "number": 42,
   "string": "bar",
+  "notAVal": "aVal",
   "array": ["one", 2, [3]],
   "object": {"foo": "bar"}
 }
@@ -60,6 +61,7 @@ func TestShow(t *testing.T) {
 			"-J", filepath.FromSlash("../testdata/lib"),
 			"-o", format,
 			filepath.FromSlash("../testdata/test.jsonnet"),
+			"-V", "aVar=aVal",
 		})
 
 		t.Log("output is", output)

testdata/test.jsonnet

 local test = import "test.libsonnet";
+local aVar = std.extVar("aVar");
 
 {
   apiVersion: "v1",
@@ -6,6 +7,7 @@ local test = import "test.libsonnet";
   items: [
     test {
       string: "bar",
+      notAVal : aVar,
     }
   ],
 }