inject transformer prefix into metric

Change-Id: Iacab685a710d8f8d5b80ed0d35e5ccc22bd929cb

staging/src/k8s.io/apiserver/pkg/storage/value/metrics.go

@@ -63,7 +63,7 @@ var (
 			Name:      "transformation_operations_total",
 			Help:      "Total number of transformations.",
 		},
-		[]string{"transformation_type", "status"},
+		[]string{"transformation_type", "transformer_prefix", "status"},
 	)
 
 	deprecatedTransformerFailuresTotal = prometheus.NewCounterVec(
@@ -130,8 +130,8 @@ func RegisterMetrics() {
 
 // RecordTransformation records latencies and count of TransformFromStorage and TransformToStorage operations.
 // Note that transformation_failures_total metric is deprecated, use transformation_operations_total instead.
-func RecordTransformation(transformationType string, start time.Time, err error) {
+func RecordTransformation(transformationType, transformerPrefix string, start time.Time, err error) {
-	transformerOperationsTotal.WithLabelValues(transformationType, status.Code(err).String()).Inc()
+	transformerOperationsTotal.WithLabelValues(transformationType, transformerPrefix, status.Code(err).String()).Inc()
 
 	switch {
 	case err == nil:

staging/src/k8s.io/apiserver/pkg/storage/value/metrics_test.go

@@ -49,7 +49,7 @@ func TestTotals(t *testing.T) {
   apiserver_storage_transformation_failures_total{transformation_type="encrypt"} 1
 	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
   # TYPE apiserver_storage_transformation_operations_total counter
-  apiserver_storage_transformation_operations_total{status="Unknown",transformation_type="encrypt"} 1
+  apiserver_storage_transformation_operations_total{status="Unknown",transformation_type="encrypt",transformer_prefix="k8s:enc:kms:v1:"} 1
 `,
 		},
 		{
@@ -61,7 +61,7 @@ func TestTotals(t *testing.T) {
 			want: `
 	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
   # TYPE apiserver_storage_transformation_operations_total counter
-  apiserver_storage_transformation_operations_total{status="OK",transformation_type="encrypt"} 1
+  apiserver_storage_transformation_operations_total{status="OK",transformation_type="encrypt",transformer_prefix="k8s:enc:kms:v1:"} 1
 `,
 		},
 		{
@@ -77,7 +77,7 @@ func TestTotals(t *testing.T) {
   apiserver_storage_transformation_failures_total{transformation_type="encrypt"} 1
 	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
   # TYPE apiserver_storage_transformation_operations_total counter
-  apiserver_storage_transformation_operations_total{status="FailedPrecondition",transformation_type="encrypt"} 1
+  apiserver_storage_transformation_operations_total{status="FailedPrecondition",transformation_type="encrypt",transformer_prefix="k8s:enc:kms:v1:"} 1
 `,
 		},
 	}
@@ -86,7 +86,7 @@ func TestTotals(t *testing.T) {
 
 	for _, tt := range testCases {
 		t.Run(tt.desc, func(t *testing.T) {
-			RecordTransformation("encrypt", time.Now(), tt.error)
+			RecordTransformation("encrypt", "k8s:enc:kms:v1:", time.Now(), tt.error)
 			defer transformerOperationsTotal.Reset()
 			defer deprecatedTransformerFailuresTotal.Reset()
 			if err := testutil.GatherAndCompare(prometheus.DefaultGatherer, strings.NewReader(tt.want), tt.metrics...); err != nil {

staging/src/k8s.io/apiserver/pkg/storage/value/transformer.go

@@ -85,18 +85,12 @@ func (t *MutableTransformer) Set(transformer Transformer) {
 }
 
 func (t *MutableTransformer) TransformFromStorage(data []byte, context Context) (out []byte, stale bool, err error) {
-	defer func(start time.Time) {
-		RecordTransformation("from_storage", start, err)
-	}(time.Now())
 	t.lock.RLock()
 	transformer := t.transformer
 	t.lock.RUnlock()
 	return transformer.TransformFromStorage(data, context)
 }
 func (t *MutableTransformer) TransformToStorage(data []byte, context Context) (out []byte, err error) {
-	defer func(start time.Time) {
-		RecordTransformation("to_storage", start, err)
-	}(time.Now())
 	t.lock.RLock()
 	transformer := t.transformer
 	t.lock.RUnlock()
@@ -134,28 +128,37 @@ func NewPrefixTransformers(err error, transformers ...PrefixTransformer) Transfo
 // the result of transforming the value. It will always mark any transformation as stale that is not using
 // the first transformer.
 func (t *prefixTransformers) TransformFromStorage(data []byte, context Context) ([]byte, bool, error) {
+	start := time.Now()
 	for i, transformer := range t.transformers {
 		if bytes.HasPrefix(data, transformer.Prefix) {
 			result, stale, err := transformer.Transformer.TransformFromStorage(data[len(transformer.Prefix):], context)
 			// To migrate away from encryption, user can specify an identity transformer higher up
 			// (in the config file) than the encryption transformer. In that scenario, the identity transformer needs to
 			// identify (during reads from disk) whether the data being read is encrypted or not. If the data is encrypted,
-			// it shall throw an error, but that error should not prevent subsequent transformers from being tried.
+			// it shall throw an error, but that error should not prevent the next subsequent transformer from being tried.
 			if len(transformer.Prefix) == 0 && err != nil {
 				continue
 			}
+			if len(transformer.Prefix) == 0 {
+				RecordTransformation("from_storage", "identity", start, err)
+			} else {
+				RecordTransformation("from_storage", string(transformer.Prefix), start, err)
+			}
 			return result, stale || i != 0, err
 		}
 	}
+	RecordTransformation("from_storage", "unknown", start, t.err)
 	return nil, false, t.err
 }
 
 // TransformToStorage uses the first transformer and adds its prefix to the data.
 func (t *prefixTransformers) TransformToStorage(data []byte, context Context) ([]byte, error) {
+	start := time.Now()
 	transformer := t.transformers[0]
 	prefixedData := make([]byte, len(transformer.Prefix), len(data)+len(transformer.Prefix))
 	copy(prefixedData, transformer.Prefix)
 	result, err := transformer.Transformer.TransformToStorage(data, context)
+	RecordTransformation("to_storage", string(transformer.Prefix), start, err)
 	if err != nil {
 		return nil, err
 	}

staging/src/k8s.io/apiserver/pkg/storage/value/transformer_test.go

@@ -19,7 +19,11 @@ package value
 import (
 	"bytes"
 	"fmt"
+	"strings"
 	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/testutil"
 )
 
 type testTransformer struct {
@@ -99,3 +103,149 @@ func TestPrefixTo(t *testing.T) {
 		}
 	}
 }
+
+func TestPrefixFromMetrics(t *testing.T) {
+	testErr := fmt.Errorf("test error")
+	transformerErr := fmt.Errorf("test error")
+	identityTransformer := PrefixTransformer{Prefix: []byte{}, Transformer: &testTransformer{from: []byte("value1")}}
+	identityTransformerErr := PrefixTransformer{Prefix: []byte{}, Transformer: &testTransformer{err: transformerErr}}
+	otherTransformer := PrefixTransformer{Prefix: []byte("other:"), Transformer: &testTransformer{from: []byte("value1")}}
+	otherTransformerErr := PrefixTransformer{Prefix: []byte("other:"), Transformer: &testTransformer{err: transformerErr}}
+
+	testCases := []struct {
+		desc    string
+		input   []byte
+		prefix  Transformer
+		metrics []string
+		want    string
+		err     error
+	}{
+		{
+			desc:   "identity prefix",
+			input:  []byte("value"),
+			prefix: NewPrefixTransformers(testErr, identityTransformer, otherTransformer),
+			metrics: []string{
+				"apiserver_storage_transformation_operations_total",
+			},
+			want: `
+	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
+  # TYPE apiserver_storage_transformation_operations_total counter
+  apiserver_storage_transformation_operations_total{status="OK",transformation_type="from_storage",transformer_prefix="identity"} 1
+  `,
+			err: nil,
+		},
+		{
+			desc:   "other prefix (ok)",
+			input:  []byte("other:value"),
+			prefix: NewPrefixTransformers(testErr, identityTransformerErr, otherTransformer),
+			metrics: []string{
+				"apiserver_storage_transformation_operations_total",
+			},
+			want: `
+	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
+  # TYPE apiserver_storage_transformation_operations_total counter
+  apiserver_storage_transformation_operations_total{status="OK",transformation_type="from_storage",transformer_prefix="other:"} 1
+  `,
+			err: nil,
+		},
+		{
+			desc:   "other prefix (error)",
+			input:  []byte("other:value"),
+			prefix: NewPrefixTransformers(testErr, identityTransformerErr, otherTransformerErr),
+			metrics: []string{
+				"apiserver_storage_transformation_operations_total",
+			},
+			want: `
+	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
+  # TYPE apiserver_storage_transformation_operations_total counter
+  apiserver_storage_transformation_operations_total{status="Unknown",transformation_type="from_storage",transformer_prefix="other:"} 1
+  `,
+			err: nil,
+		},
+		{
+			desc:   "unknown prefix",
+			input:  []byte("foo:value"),
+			prefix: NewPrefixTransformers(testErr, identityTransformerErr, otherTransformer),
+			metrics: []string{
+				"apiserver_storage_transformation_operations_total",
+			},
+			want: `
+	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
+  # TYPE apiserver_storage_transformation_operations_total counter
+  apiserver_storage_transformation_operations_total{status="Unknown",transformation_type="from_storage",transformer_prefix="unknown"} 1
+  `,
+			err: nil,
+		},
+	}
+
+	RegisterMetrics()
+	transformerOperationsTotal.Reset()
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			tc.prefix.TransformFromStorage(tc.input, nil)
+			defer transformerOperationsTotal.Reset()
+			if err := testutil.GatherAndCompare(prometheus.DefaultGatherer, strings.NewReader(tc.want), tc.metrics...); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestPrefixToMetrics(t *testing.T) {
+	testErr := fmt.Errorf("test error")
+	transformerErr := fmt.Errorf("test error")
+	otherTransformer := PrefixTransformer{Prefix: []byte("other:"), Transformer: &testTransformer{from: []byte("value1")}}
+	otherTransformerErr := PrefixTransformer{Prefix: []byte("other:"), Transformer: &testTransformer{err: transformerErr}}
+
+	testCases := []struct {
+		desc    string
+		input   []byte
+		prefix  Transformer
+		metrics []string
+		want    string
+		err     error
+	}{
+		{
+			desc:   "ok",
+			input:  []byte("value"),
+			prefix: NewPrefixTransformers(testErr, otherTransformer),
+			metrics: []string{
+				"apiserver_storage_transformation_operations_total",
+			},
+			want: `
+	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
+  # TYPE apiserver_storage_transformation_operations_total counter
+  apiserver_storage_transformation_operations_total{status="OK",transformation_type="to_storage",transformer_prefix="other:"} 1
+  `,
+			err: nil,
+		},
+		{
+			desc:   "error",
+			input:  []byte("value"),
+			prefix: NewPrefixTransformers(testErr, otherTransformerErr),
+			metrics: []string{
+				"apiserver_storage_transformation_operations_total",
+			},
+			want: `
+	# HELP apiserver_storage_transformation_operations_total Total number of transformations.
+  # TYPE apiserver_storage_transformation_operations_total counter
+  apiserver_storage_transformation_operations_total{status="Unknown",transformation_type="to_storage",transformer_prefix="other:"} 1
+  `,
+			err: nil,
+		},
+	}
+
+	RegisterMetrics()
+	transformerOperationsTotal.Reset()
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			tc.prefix.TransformToStorage(tc.input, nil)
+			defer transformerOperationsTotal.Reset()
+			if err := testutil.GatherAndCompare(prometheus.DefaultGatherer, strings.NewReader(tc.want), tc.metrics...); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}