Adding a unit test for pkg/cgroup/fs/memory.go

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)

cgroups/fs/memory_test.go

@@ -0,0 +1,123 @@
+package fs
+
+import (
+	"testing"
+)
+
+const (
+	memoryStatContents = `cache 512
+rss 1024`
+	memoryUsageContents    = "2048\n"
+	memoryMaxUsageContents = "4096\n"
+)
+
+func TestMemoryStats(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.stat":               memoryStatContents,
+		"memory.usage_in_bytes":     memoryUsageContents,
+		"memory.max_usage_in_bytes": memoryMaxUsageContents,
+	})
+
+	memory := &memoryGroup{}
+	stats, err := memory.Stats(helper.CgroupData)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expectedStats := map[string]float64{"cache": 512.0, "rss": 1024.0, "usage_in_bytes": 2048.0, "max_usage_in_bytes": 4096.0}
+	expectStats(t, expectedStats, stats)
+}
+
+func TestMemoryStatsNoStatFile(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.usage_in_bytes":     memoryUsageContents,
+		"memory.max_usage_in_bytes": memoryMaxUsageContents,
+	})
+
+	memory := &memoryGroup{}
+	_, err := memory.Stats(helper.CgroupData)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}
+
+func TestMemoryStatsNoUsageFile(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.stat":               memoryStatContents,
+		"memory.max_usage_in_bytes": memoryMaxUsageContents,
+	})
+
+	memory := &memoryGroup{}
+	_, err := memory.Stats(helper.CgroupData)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}
+
+func TestMemoryStatsNoMaxUsageFile(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.stat":           memoryStatContents,
+		"memory.usage_in_bytes": memoryUsageContents,
+	})
+
+	memory := &memoryGroup{}
+	_, err := memory.Stats(helper.CgroupData)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}
+
+func TestMemoryStatsBadStatFile(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.stat":               "rss rss",
+		"memory.usage_in_bytes":     memoryUsageContents,
+		"memory.max_usage_in_bytes": memoryMaxUsageContents,
+	})
+
+	memory := &memoryGroup{}
+	_, err := memory.Stats(helper.CgroupData)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}
+
+func TestMemoryStatsBadUsageFile(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.stat":               memoryStatContents,
+		"memory.usage_in_bytes":     "bad",
+		"memory.max_usage_in_bytes": memoryMaxUsageContents,
+	})
+
+	memory := &memoryGroup{}
+	_, err := memory.Stats(helper.CgroupData)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}
+
+func TestMemoryStatsBadMaxUsageFile(t *testing.T) {
+	helper := NewCgroupTestUtil("memory", t)
+	defer helper.cleanup()
+	helper.writeFileContents(map[string]string{
+		"memory.stat":               memoryStatContents,
+		"memory.usage_in_bytes":     memoryUsageContents,
+		"memory.max_usage_in_bytes": "bad",
+	})
+
+	memory := &memoryGroup{}
+	_, err := memory.Stats(helper.CgroupData)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}