Check for config map key ref for unused config map test

checks/basic/unused_config_map.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2019 DigitalOcean
+Copyright 2020 DigitalOcean
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -155,6 +155,11 @@ func checkEnvVars(containers []corev1.Container, namespace string) []kube.Identi
 				refs = append(refs, kube.Identifier{Name: env.ConfigMapRef.LocalObjectReference.Name, Namespace: namespace})
 			}
 		}
+		for _, env := range container.Env {
+			if env.ValueFrom != nil && env.ValueFrom.ConfigMapKeyRef != nil {
+				refs = append(refs, kube.Identifier{Name: env.ValueFrom.ConfigMapKeyRef.LocalObjectReference.Name, Namespace: namespace})
+			}
+		}
 	}
 	return refs
 }

checks/basic/unused_config_map_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2019 DigitalOcean
+Copyright 2020 DigitalOcean
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -65,6 +65,11 @@ func TestUnusedConfigMapWarning(t *testing.T) {
 			objs:     configMapEnvSource(),
 			expected: nil,
 		},
+		{
+			name:     "environment variable value from references config map",
+			objs:     configMapEnvVarValueFromSource(),
+			expected: nil,
+		},
 		{
 			name:     "projected volume references config map",
 			objs:     projectedVolume(),
@@ -198,3 +203,26 @@ func configMapEnvSource() *kube.Objects {
 	}
 	return objs
 }
+
+func configMapEnvVarValueFromSource() *kube.Objects {
+	objs := initConfigMap()
+	objs.Pods.Items[0].Spec = corev1.PodSpec{
+		Containers: []corev1.Container{
+			{
+				Name:  "test-container",
+				Image: "docker.io/nginx",
+				Env: []corev1.EnvVar{
+					{
+						Name: "special_env_var",
+						ValueFrom: &corev1.EnvVarSource{
+							ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+								LocalObjectReference: corev1.LocalObjectReference{Name: "cm_foo"},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+	return objs
+}