third_party/go/patches/k8s-native-metrics.patch

From e3b5a31bff00c89fc95f85212bf0943d46692616 Mon Sep 17 00:00:00 2001
From: Lorenz Brun <lorenz@brun.one>
Date: Tue, 17 Mar 2020 21:41:08 +0100
Subject: [PATCH 2/2] Add a native volume metrics implementation

---
 pkg/volume/metrics_native.go      | 101 +++++++++++++++++++++++++++++
 pkg/volume/metrics_native_test.go | 102 ++++++++++++++++++++++++++++++
 2 files changed, 203 insertions(+)
 create mode 100644 pkg/volume/metrics_native.go
 create mode 100644 pkg/volume/metrics_native_test.go

diff --git a/pkg/volume/metrics_native.go b/pkg/volume/metrics_native.go
new file mode 100644
index 00000000000..3934b946f2e
--- /dev/null
+++ b/pkg/volume/metrics_native.go
@@ -0,0 +1,101 @@
+/*
+Copyright 2020 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 volume
+
+import (
+	"os"
+	"path/filepath"
+
+	"golang.org/x/sys/unix"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+var _ MetricsProvider = &metricsNative{}
+
+// MetricsNative represents a MetricsProvider that calculates the volume metrics with either a quota
+// or by walking the path using syscalls.
+type metricsNative struct {
+	path string
+}
+
+// NewMetricsNative returns a new metricsNative provider
+func NewMetricsNative(path string) MetricsProvider {
+	return &metricsNative{path}
+}
+
+// GetMetrics returns an empty Metrics and an error.
+// See MetricsProvider.GetMetrics
+func (m *metricsNative) GetMetrics() (*Metrics, error) {
+	var inodesCount int64
+	var bytesCount int64
+
+	var getMetricsRecursive func(path string) error
+	getMetricsRecursive = func(path string) error {
+		var stat unix.Stat_t
+		err := unix.Lstat(path, &stat)
+		if os.IsNotExist(err) {
+			return nil
+		} else if err != nil {
+			return err
+		}
+		// TODO: This double-counts hardlinks
+		bytesCount += stat.Blocks * 512
+		inodesCount++
+		if stat.Mode&unix.S_IFDIR != 0 && stat.Mode&unix.S_IFLNK == 0 {
+			fd, err := os.Open(path)
+			if os.IsNotExist(err) {
+				return nil
+			} else if err != nil {
+				return err
+			}
+			// We manually close fd before recursing, otherwise we have too many FDs open
+
+			entries, err := fd.Readdirnames(0)
+			if err != nil {
+				fd.Close()
+				return err
+			}
+			fd.Close()
+			for _, entry := range entries {
+				if err := getMetricsRecursive(filepath.Join(path, entry)); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+
+	if err := getMetricsRecursive(m.path); err != nil {
+		return &Metrics{}, err
+	}
+
+	var statfs unix.Statfs_t
+	if err := unix.Statfs(m.path, &statfs); err != nil {
+		return &Metrics{}, err
+	}
+
+	return &Metrics{
+		Time:       metav1.Now(),
+		Used:       resource.NewQuantity(bytesCount, resource.BinarySI),
+		InodesUsed: resource.NewQuantity(inodesCount, resource.BinarySI),
+		Available:  resource.NewQuantity(int64(statfs.Bavail)*statfs.Bsize, resource.BinarySI),
+		Capacity:   resource.NewQuantity(int64(statfs.Blocks)*statfs.Bsize, resource.BinarySI),
+		Inodes:     resource.NewQuantity(int64(statfs.Files)*statfs.Bsize, resource.BinarySI),
+		InodesFree: resource.NewQuantity(int64(statfs.Ffree)*statfs.Bsize, resource.BinarySI),
+	}, nil
+}
diff --git a/pkg/volume/metrics_native_test.go b/pkg/volume/metrics_native_test.go
new file mode 100644
index 00000000000..2d5546591ce
--- /dev/null
+++ b/pkg/volume/metrics_native_test.go
@@ -0,0 +1,102 @@
+// +build linux
+
+/*
+Copyright 2015 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 volume_test
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	utiltesting "k8s.io/client-go/util/testing"
+	. "k8s.io/kubernetes/pkg/volume"
+	volumetest "k8s.io/kubernetes/pkg/volume/testing"
+)
+
+// TestMetricsNativeGetCapacity tests that MetricsNative can read disk usage
+// for path
+func TestMetricsNativeGetCapacity(t *testing.T) {
+	tmpDir, err := utiltesting.MkTmpdir("metrics_du_test")
+	if err != nil {
+		t.Fatalf("Can't make a tmp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+	metrics := NewMetricsNative(tmpDir)
+
+	expectedEmptyDirUsage, err := volumetest.FindEmptyDirectoryUsageOnTmpfs()
+	if err != nil {
+		t.Errorf("Unexpected error finding expected empty directory usage on tmpfs: %v", err)
+	}
+
+	actual, err := metrics.GetMetrics()
+	if err != nil {
+		t.Errorf("Unexpected error when calling GetMetrics %v", err)
+	}
+	if e, a := expectedEmptyDirUsage.Value(), actual.Used.Value(); e != a {
+		t.Errorf("Unexpected value for empty directory; expected %v, got %v", e, a)
+	}
+
+	// TODO(pwittroc): Figure out a way to test these values for correctness, maybe by formatting and mounting a file
+	// as a filesystem
+	if a := actual.Capacity.Value(); a <= 0 {
+		t.Errorf("Expected Capacity %d to be greater than 0.", a)
+	}
+	if a := actual.Available.Value(); a <= 0 {
+		t.Errorf("Expected Available %d to be greater than 0.", a)
+	}
+
+	// Write a file in a directory and expect Used to increase
+	os.MkdirAll(filepath.Join(tmpDir, "d1"), 0755)
+	ioutil.WriteFile(filepath.Join(tmpDir, "d1", "f1"), []byte("Hello World"), os.ModeTemporary)
+	actual, err = metrics.GetMetrics()
+	if err != nil {
+		t.Errorf("Unexpected error when calling GetMetrics %v", err)
+	}
+	if e, a := (2*expectedEmptyDirUsage.Value() + getExpectedBlockSize(filepath.Join(tmpDir, "d1", "f1"))), actual.Used.Value(); e != a {
+		t.Errorf("Unexpected Used for directory with file.  Expected %v, got %d.", e, a)
+	}
+}
+
+// TestMetricsNativeRequireInit tests that if MetricsNative is not initialized with a path, GetMetrics
+// returns an error
+func TestMetricsNativeRequirePath(t *testing.T) {
+	metrics := NewMetricsNative("")
+	actual, err := metrics.GetMetrics()
+	expected := &Metrics{}
+	if !volumetest.MetricsEqualIgnoreTimestamp(actual, expected) {
+		t.Errorf("Expected empty Metrics from uninitialized MetricsNative, actual %v", *actual)
+	}
+	if err == nil {
+		t.Errorf("Expected error when calling GetMetrics on uninitialized MetricsNative, actual nil")
+	}
+}
+
+// TestMetricsNativeRealDirectory tests that if MetricsNative is initialized to a non-existent path, GetMetrics
+// returns an error
+func TestMetricsNativeRequireRealDirectory(t *testing.T) {
+	metrics := NewMetricsNative("/not/a/real/directory")
+	actual, err := metrics.GetMetrics()
+	expected := &Metrics{}
+	if !volumetest.MetricsEqualIgnoreTimestamp(actual, expected) {
+		t.Errorf("Expected empty Metrics from incorrectly initialized MetricsNative, actual %v", *actual)
+	}
+	if err == nil {
+		t.Errorf("Expected error when calling GetMetrics on incorrectly initialized MetricsNative, actual nil")
+	}
+}
-- 
2.25.1