fix nil map bug

Author: mattes

config.go

@@ -147,18 +147,27 @@ func ParseConfig(b io.Reader) (*Config, error) {
 			deploy.CloudInitPath = c.Common.CloudInitPath
 		}
 
+		if deploy.Vars == nil {
+			deploy.Vars = make(map[string]string)
+		}
 		for k, v := range c.Common.Vars {
 			if _, ok := deploy.Vars[k]; !ok {
 				deploy.Vars[k] = v
 			}
 		}
 
+		if deploy.Labels == nil {
+			deploy.Labels = make(map[string]string)
+		}
 		for k, v := range c.Common.Labels {
 			if _, ok := deploy.Labels[k]; !ok {
 				deploy.Labels[k] = v
 			}
 		}
 
+		if deploy.Metadata == nil {
+			deploy.Metadata = make(map[string]string)
+		}
 		for k, v := range c.Common.Metadata {
 			if _, ok := deploy.Metadata[k]; !ok {
 				deploy.Metadata[k] = v

config_test.go

@@ -181,6 +181,30 @@ deploys:
 	assert.Equal(t, "12", c.Deploys[0].UpdatePolicy.MaxUnavailable)
 }
 
+func TestNilMaps(t *testing.T) {
+	config := `
+common: 
+  vars:
+    var1: x
+  labels:
+    label1: x
+  metadata:
+    metadata1: x
+  tags:
+    - tag1
+
+deploys:
+  - name: test
+    region: w
+    instance_group: x
+    instance_template_base: y
+    instance_template: z
+`
+
+	_, err := ParseConfig(strings.NewReader(config))
+	require.NoError(t, err)
+}
+
 func TestExpandShellRe(t *testing.T) {
 	in := `$foo $FOO ${foo} a${foo}b \$foo \${foo} a\${foo}b $foo-$foo $foo-${foo} $fo $f`