pkg/cdi: add Spec name generation functions.

Add functions for generating ordinary or transient
Spec file names. The generated names can be passed
to WriteSpec() to create the actual Spec files and
to RemoveSpec() to remove them.

Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

Author: klihub

pkg/cdi/cache_test.go

@@ -17,8 +17,10 @@
 package cdi
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -30,6 +32,7 @@ import (
 	oci "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/require"
+	"sigs.k8s.io/yaml"
 )
 
 func TestNewCache(t *testing.T) {
@@ -1634,6 +1637,216 @@ containerEdits:
 	}
 }
 
+func TestCacheTransientSpecs(t *testing.T) {
+	type testCase struct {
+		name         string
+		specs        []string
+		invalid      map[int]bool
+		expected     [][]string
+		numSpecFiles []int
+	}
+	for _, tc := range []*testCase{
+		{
+			name: "invalid spec",
+			specs: []string{
+				`
+cdiVersion: "0.3.0"
+kind:       "vendor.comdevice"
+devices:
+  - name: "dev1"
+    containerEdits:
+      deviceNodes:
+      - path: "/dev/vendor1-dev1"
+        type: b
+        major: 10
+        minor: 1`,
+			},
+			invalid: map[int]bool{
+				0: true,
+			},
+		},
+		{
+			name: "add/remove one valid spec",
+			specs: []string{
+				`
+cdiVersion: "0.3.0"
+kind:       "vendor.com/device"
+devices:
+  - name: "dev1"
+    containerEdits:
+      deviceNodes:
+      - path: "/dev/vendor-dev1"
+        type: b
+        major: 10
+        minor: 1
+`,
+				"-0",
+			},
+			expected: [][]string{
+				[]string{
+					"vendor.com/device=dev1",
+				},
+				nil,
+			},
+			numSpecFiles: []int{
+				1,
+				0,
+			},
+		},
+		{
+			name: "add/remove multiple valid specs",
+			specs: []string{
+				`
+cdiVersion: "0.3.0"
+kind:       "vendor.com/device"
+devices:
+  - name: "dev1"
+    containerEdits:
+      deviceNodes:
+      - path: "/dev/vendor-dev1"
+        type: b
+        major: 10
+        minor: 1
+`,
+				`
+cdiVersion: "0.3.0"
+kind:       "vendor.com/device"
+devices:
+  - name: "dev2"
+    containerEdits:
+      deviceNodes:
+      - path: "/dev/vendor-dev2"
+        type: b
+        major: 10
+        minor: 2
+`,
+				`
+cdiVersion: "0.3.0"
+kind:       "vendor.com/device"
+devices:
+  - name: "dev3"
+    containerEdits:
+      deviceNodes:
+      - path: "/dev/vendor-dev3"
+        type: b
+        major: 10
+        minor: 3
+  - name: "dev4"
+    containerEdits:
+      deviceNodes:
+      - path: "/dev/vendor-dev4"
+        type: b
+        major: 10
+        minor: 4
+`,
+				"-0",
+				"-1",
+				"-2",
+			},
+			expected: [][]string{
+				[]string{
+					"vendor.com/device=dev1",
+				},
+				[]string{
+					"vendor.com/device=dev1",
+					"vendor.com/device=dev2",
+				},
+				[]string{
+					"vendor.com/device=dev1",
+					"vendor.com/device=dev2",
+					"vendor.com/device=dev3",
+					"vendor.com/device=dev4",
+				},
+				[]string{
+					"vendor.com/device=dev2",
+					"vendor.com/device=dev3",
+					"vendor.com/device=dev4",
+				},
+				[]string{
+					"vendor.com/device=dev3",
+					"vendor.com/device=dev4",
+				},
+				nil,
+			},
+			numSpecFiles: []int{
+				1,
+				2,
+				3,
+				2,
+				1,
+				0,
+			},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			var (
+				dir       string
+				err       error
+				cache     *Cache
+				specFiles []os.DirEntry
+				specs     = map[int]string{}
+			)
+
+			dir, err = createSpecDirs(t, nil, nil)
+			require.NoError(t, err)
+			cache, err = NewCache(
+				WithSpecDirs(
+					filepath.Join(dir, "etc"),
+					filepath.Join(dir, "run"),
+				),
+				WithAutoRefresh(false),
+			)
+
+			require.NoError(t, err)
+			require.NotNil(t, cache)
+
+			for idx, data := range tc.specs {
+				var (
+					driver      = "test"
+					transientID string
+					raw         *cdi.Spec
+					delIdx      int
+					err         error
+				)
+
+				if data[0] == '-' {
+					delIdx, err = strconv.Atoi(string(data[1:]))
+					require.NoError(t, err)
+
+					err = cache.RemoveSpec(specs[delIdx])
+					require.NoError(t, err)
+				} else {
+					err = yaml.Unmarshal([]byte(data), &raw)
+					require.NoError(t, err)
+
+					transientID = fmt.Sprintf("id%d", idx)
+					specs[idx], err = GenerateNameForTransientSpec(raw, driver, transientID)
+					if tc.invalid[idx] {
+						require.NotNil(t, err)
+						continue
+					}
+					require.NoError(t, err)
+
+					err = cache.WriteSpec(raw, specs[idx])
+					require.NoError(t, err)
+				}
+
+				err = cache.Refresh()
+				require.NoError(t, err)
+
+				devices := cache.ListDevices()
+				require.Equal(t, tc.expected[idx], devices)
+
+				specFiles, err = os.ReadDir(
+					filepath.Join(dir, "run"),
+				)
+				require.NoError(t, err)
+				require.Equal(t, tc.numSpecFiles[idx], len(specFiles))
+			}
+		})
+	}
+}
+
 // Create and populate automatically cleaned up spec directories.
 func createSpecDirs(t *testing.T, etc, run map[string]string) (string, error) {
 	return mkTestDir(t, map[string]map[string]string{

pkg/cdi/spec.go

@@ -262,3 +262,75 @@ func validateSpec(raw *cdi.Spec) error {
 	}
 	return nil
 }
+
+// GenerateSpecName generates a vendor+class scoped Spec file name. The
+// name can be passed to WriteSpec() to write a Spec file to the file
+// system.
+//
+// vendor and class should match the vendor and class of the CDI Spec.
+// The file name is generated without a ".json" or ".yaml" extension.
+// The caller can append the desired extension to choose a particular
+// encoding. Otherwise WriteSpec() will use its default encoding.
+//
+// This function always returns the same name for the same vendor/class
+// combination. Therefore it cannot be used as such to generate multiple
+// Spec file names for a single vendor and class.
+func GenerateSpecName(vendor, class string) string {
+	return vendor + "-" + class
+}
+
+// GenerateTransientSpecName generates a vendor+class scoped transient
+// Spec file name. The name can be passed to WriteSpec() to write a Spec
+// file to the file system.
+//
+// Transient Specs are those whose lifecycle is tied to that of some
+// external entity, for instance a container. vendor and class should
+// match the vendor and class of the CDI Spec. driver can be left empty
+// if only a single CDI user is generating transient Spec files for the
+// given vendor/class combination on the host. Otherwise driver should
+// uniquely identify the caller among those that use the same vendor
+// and class. transientID should uniquely identify the external entity
+// within the scope of the caller/driver.
+//
+// The file name is generated without a ".json" or ".yaml" extension.
+// The caller can append the desired extension to choose a particular
+// encoding. Otherwise WriteSpec() will use its default encoding.
+func GenerateTransientSpecName(vendor, class, driver, transientID string) string {
+	name := vendor + "-" + class
+
+	if driver != "" {
+		name += "+" + driver
+	}
+
+	name = name + ".transient_" + transientID
+
+	return name
+}
+
+// GenerateNameForSpec generates a name for the given Spec using
+// GenerateSpecName with the vendor and class taken from the Spec.
+// On success it returns the generated name and a nil error. If
+// the Spec does not contain a valid vendor or class, it returns
+// an empty name and a non-nil error.
+func GenerateNameForSpec(raw *cdi.Spec) (string, error) {
+	vendor, class := ParseQualifier(raw.Kind)
+	if vendor == "" {
+		return "", errors.Errorf("invalid vendor/class %q in Spec", raw.Kind)
+	}
+
+	return GenerateSpecName(vendor, class), nil
+}
+
+// GenerateNameForTransientSpec generates a name for the given transient
+// Spec using GenerateTransientSpecName with the vendor and class taken
+// from the Spec. On success it returns the generated name and a nil error.
+// If the Spec does not contain a valid vendor or class, it returns an
+// an empty name and a non-nil error.
+func GenerateNameForTransientSpec(raw *cdi.Spec, driver, transientID string) (string, error) {
+	vendor, class := ParseQualifier(raw.Kind)
+	if vendor == "" {
+		return "", errors.Errorf("invalid vendor/class %q in Spec", raw.Kind)
+	}
+
+	return GenerateTransientSpecName(vendor, class, driver, transientID), nil
+}