crude var injection

Author: harsimranmaan

internal/eval/eval.go

@@ -264,6 +264,10 @@ func evaluationCode(c Context, file string) evalFn {
 			instances := load.Instances([]string{}, &load.Config{
 				Package: "_", // file that don't belong to a package
 				Dir:     filepath.Dir(file),
+				// Requires string array with values of form k=v
+				Tags: tlas,
+				// Add builtin tags
+				TagVars: load.DefaultTagVars(),
 				// Maybe we'll want to process only select files like index.cue instead of all cue files
 				//Overlay: map[string]load.Source{file: load.FromBytes(f)},
 			})

internal/eval/eval_test.go

@@ -22,6 +22,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/splunk/qbec/internal/model"
@@ -133,9 +134,11 @@ func TestEvalComponents(t *testing.T) {
 			Files: []string{"testdata/components/c.jsonnet"},
 		},
 		{
-			Name:  "cue",
-			Files: []string{"testdata/components/cue/index.cue"},
+			Name:         "cue",
+			Files:        []string{"testdata/components/cue/index.cue"},
+			TopLevelVars: []string{"fooVal=baz"},
 		},
+
 		{
 			Name:  "a",
 			Files: []string{"testdata/components/a.json"},
@@ -194,6 +197,8 @@ func TestEvalComponents(t *testing.T) {
 	obj = objs[3]
 	a.Equal("cue", obj.Component())
 	a.Equal("name-from-helper-pkg", obj.GetName())
+	a.Equal("baz", obj.GetAnnotations()["qbec.io/injectedVar"])
+	a.Equal(runtime.GOOS, obj.GetAnnotations()["qbec.io/injectedBuiltinOS"])
 
 	obj = objs[4]
 	a.Equal("d", obj.Component())

internal/eval/testdata/components/cue/index.cue

@@ -1,6 +1,12 @@
 import "qbec.io/helper"
-
+#fooVal: *"bar" | string @tag(fooVal)
 apiVersion: "v1"
 kind: "ConfigMap"
-metadata: name: helper.name
-data: foo: "bar"
+metadata: {
+  name: helper.name
+  annotations: {
+    "qbec.io/injectedVar": #fooVal
+    "qbec.io/injectedBuiltinOS": string @tag(someTagname,var=os)
+  }
+}
+data: foo: #fooVal

site/content/reference/component-evaluation.md

@@ -12,7 +12,7 @@ How qbec evaluates component code using jsonnet and what it expects the output t
 * Check immediate subdirectories of the component directory to see if they contain an `index.jsonnet`, `index.cue` or `index.yaml` file.
   If so, create a component with the sub-directory name.
     * If an `index.jsonnet` file exists load it for component processing.
-    * If an `index.cue` file exists  load it for component processing.
+    * If an `index.cue` file exists  load it for component processing (experimental).
     * If an `index.yaml` file exists load all `.json` and `.yaml` files in the subdirectory.
 
 ## Jsonnet evaluation