Omit nil or empty field when calculating hash value

pkg/kubelet/container/container_hash_test.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package container
+
+import (
+	"encoding/json"
+	"testing"
+
+	"k8s.io/api/core/v1"
+)
+
+var (
+	sampleContainer = `
+{
+  "name": "test_container",
+  "image": "foo/image:v1",
+  "command": [
+    "/bin/testcmd"
+  ],
+  "args": [
+    "/bin/sh",
+    "-c",
+    "echo abc"
+  ],
+  "ports": [
+    {
+      "containerPort": 8001
+    }
+  ],
+  "env": [
+    {
+      "name": "ENV_FOO",
+      "value": "bar"
+    },
+    {
+      "name": "ENV_BAR",
+      "valueFrom": {
+        "secretKeyRef": {
+          "name": "foo",
+          "key": "bar",
+          "optional": true
+        }
+      }
+    }
+  ],
+  "resources": {
+    "limits": {
+      "foo": "1G"
+    },
+    "requests": {
+      "foo": "500M"
+    }
+  }
+}
+`
+
+	sampleV115HashValue = uint64(0x311670a)
+	sampleV116HashValue = sampleV115HashValue
+)
+
+func TestConsistentHashContainer(t *testing.T) {
+	container := &v1.Container{}
+	if err := json.Unmarshal([]byte(sampleContainer), container); err != nil {
+		t.Error(err)
+	}
+
+	currentHash := HashContainer(container)
+	if currentHash != sampleV116HashValue {
+		t.Errorf("mismatched hash value with v1.16")
+	}
+
+	if currentHash != sampleV115HashValue {
+		t.Errorf("mismatched hash value with v1.15")
+	}
+}