Merge pull request #9268 from hashicorp/jbardin/hcl-maps

Get rid of the list when parsing HCL maps for vars

command/flag_kv.go

@@ -112,6 +112,10 @@ func loadKVFile(rawPath string) (map[string]interface{}, error) {
 				"Decoding errors are usually caused by an invalid format.",
 			err)
 	}
+	err = flattenMultiMaps(result)
+	if err != nil {
+		return nil, err
+	}
 
 	return result, nil
 }
@@ -202,10 +206,34 @@ func parseVarFlagAsHCL(input string) (string, interface{}, error) {
 		return "", nil, fmt.Errorf("Cannot parse value for variable %s (%q) as valid HCL. Only one value may be specified.", probablyName, input)
 	}
 
-	for k, v := range decoded {
+	err = flattenMultiMaps(decoded)
-		return k, v, nil
+	if err != nil {
+		return probablyName, "", err
 	}
 
-	// Should be unreachable
+	var k string
-	return "", nil, fmt.Errorf("No value for variable: %s", input)
+	var v interface{}
+	for k, v = range decoded {
+		break
+	}
+	return k, v, nil
+}
+
+// Variables don't support any type that can be configured via multiple
+// declarations of the same HCL map, so any instances of
+// []map[string]interface{} are either a single map that can be flattened, or
+// are invalid config.
+func flattenMultiMaps(m map[string]interface{}) error {
+	for k, v := range m {
+		switch v := v.(type) {
+		case []map[string]interface{}:
+			switch {
+			case len(v) > 1:
+				return fmt.Errorf("multiple map declarations not supported for variables")
+			case len(v) == 1:
+				m[k] = v[0]
+			}
+		}
+	}
+	return nil
 }

command/flag_kv_test.go

@@ -119,13 +119,11 @@ func TestFlagTypedKV(t *testing.T) {
 		{
 			`key={"hello" = "world", "foo" = "bar"}`,
 			map[string]interface{}{
-				"key": []map[string]interface{}{
+				"key": map[string]interface{}{
-					map[string]interface{}{
 					"hello": "world",
 					"foo":   "bar",
 				},
 			},
-			},
 			false,
 		},
 
@@ -193,6 +191,10 @@ func TestFlagKVFile(t *testing.T) {
 	inputLibucl := `
 foo = "bar"
 `
+	inputMap := `
+foo = {
+	k = "v"
+}`
 
 	inputJson := `{
 		"foo": "bar"}`
@@ -219,6 +221,16 @@ foo = "bar"
 			map[string]interface{}{"map.key": "foo"},
 			false,
 		},
+
+		{
+			inputMap,
+			map[string]interface{}{
+				"foo": map[string]interface{}{
+					"k": "v",
+				},
+			},
+			false,
+		},
 	}
 
 	path := testTempFile(t)

terraform/eval_output.go

@@ -98,6 +98,19 @@ func (n *EvalWriteOutput) Eval(ctx EvalContext) (interface{}, error) {
 			Sensitive: n.Sensitive,
 			Value:     valueTyped,
 		}
+	case []map[string]interface{}:
+		// an HCL map is multi-valued, so if this was read out of a config the
+		// map may still be in a slice.
+		if len(valueTyped) == 1 {
+			mod.Outputs[n.Name] = &OutputState{
+				Type:      "map",
+				Sensitive: n.Sensitive,
+				Value:     valueTyped[0],
+			}
+			break
+		}
+		return nil, fmt.Errorf("output %s type (%T) with %d values not valid for type map",
+			n.Name, valueTyped, len(valueTyped))
 	default:
 		return nil, fmt.Errorf("output %s is not a valid type (%T)\n", n.Name, valueTyped)
 	}

terraform/eval_output_test.go

@@ -0,0 +1,56 @@
+package terraform
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestEvalWriteMapOutput(t *testing.T) {
+	ctx := new(MockEvalContext)
+	ctx.StateState = NewState()
+	ctx.StateLock = new(sync.RWMutex)
+
+	cases := []struct {
+		name string
+		cfg  *ResourceConfig
+		err  bool
+	}{
+		{
+			// Eval should recognize a single map in a slice, and collapse it
+			// into the map value
+			"single-map",
+			&ResourceConfig{
+				Config: map[string]interface{}{
+					"value": []map[string]interface{}{
+						map[string]interface{}{"a": "b"},
+					},
+				},
+			},
+			false,
+		},
+		{
+			// we can't apply a multi-valued map to a variable, so this should error
+			"multi-map",
+			&ResourceConfig{
+				Config: map[string]interface{}{
+					"value": []map[string]interface{}{
+						map[string]interface{}{"a": "b"},
+						map[string]interface{}{"c": "d"},
+					},
+				},
+			},
+			true,
+		},
+	}
+
+	for _, tc := range cases {
+		evalNode := &EvalWriteOutput{Name: tc.name}
+		ctx.InterpolateConfigResult = tc.cfg
+		t.Run(tc.name, func(t *testing.T) {
+			_, err := evalNode.Eval(ctx)
+			if err != nil && !tc.err {
+				t.Fatal(err)
+			}
+		})
+	}
+}