cache schemas downloaded over HTTP

pkg/cache/cache.go

@@ -0,0 +1,6 @@
+package cache
+
+type Cache interface {
+	Get(resourceKind, resourceAPIVersion, k8sVersion string) (interface{}, error)
+	Set(resourceKind, resourceAPIVersion, k8sVersion string, schema interface{}) error
+}

pkg/cache/inmemory.go

@@ -0,0 +1,49 @@
+package cache
+
+import (
+	"fmt"
+	"sync"
+)
+
+// SchemaCache is a cache for downloaded schemas, so each file is only retrieved once
+// It is different from pkg/registry/http_cache.go in that:
+//   - This cache caches the parsed Schemas
+type inMemory struct {
+	sync.RWMutex
+	schemas map[string]interface{}
+}
+
+// New creates a new cache for downloaded schemas
+func NewInMemoryCache() Cache {
+	return &inMemory{
+		schemas: map[string]interface{}{},
+	}
+}
+
+func key(resourceKind, resourceAPIVersion, k8sVersion string) string {
+	return fmt.Sprintf("%s-%s-%s", resourceKind, resourceAPIVersion, k8sVersion)
+}
+
+// Get retrieves the JSON schema given a resource signature
+func (c *inMemory) Get(resourceKind, resourceAPIVersion, k8sVersion string) (interface{}, error) {
+	k := key(resourceKind, resourceAPIVersion, k8sVersion)
+	c.RLock()
+	defer c.RUnlock()
+	schema, ok := c.schemas[k]
+
+	if ok == false {
+		return nil, fmt.Errorf("schema not found in in-memory cache")
+	}
+
+	return schema, nil
+}
+
+// Set adds a JSON schema to the schema cache
+func (c *inMemory) Set(resourceKind, resourceAPIVersion, k8sVersion string, schema interface{}) error {
+	k := key(resourceKind, resourceAPIVersion, k8sVersion)
+	c.Lock()
+	defer c.Unlock()
+	c.schemas[k] = schema
+
+	return nil
+}

pkg/cache/ondisk.go

@@ -0,0 +1,48 @@
+package cache
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"sync"
+)
+
+type onDisk struct {
+	sync.RWMutex
+	folder string
+}
+
+// New creates a new cache for downloaded schemas
+func NewOnDiskCache(cache string) Cache {
+	return &onDisk{
+		folder: cache,
+	}
+}
+
+func cachePath(folder, resourceKind, resourceAPIVersion, k8sVersion string) string {
+	hash := md5.Sum([]byte(fmt.Sprintf("%s-%s-%s", resourceKind, resourceAPIVersion, k8sVersion)))
+	return path.Join(folder, hex.EncodeToString(hash[:]))
+}
+
+// Get retrieves the JSON schema given a resource signature
+func (c *onDisk) Get(resourceKind, resourceAPIVersion, k8sVersion string) (interface{}, error) {
+	c.RLock()
+	defer c.RUnlock()
+
+	f, err := os.Open(cachePath(c.folder, resourceKind, resourceAPIVersion, k8sVersion))
+	if err != nil {
+		return nil, err
+	}
+
+	return ioutil.ReadAll(f)
+}
+
+// Set adds a JSON schema to the schema cache
+func (c *onDisk) Set(resourceKind, resourceAPIVersion, k8sVersion string, schema interface{}) error {
+	c.Lock()
+	defer c.Unlock()
+	return ioutil.WriteFile(cachePath(c.folder, resourceKind, resourceAPIVersion, k8sVersion), schema.([]byte), 0644)
+}

pkg/cache/schemacache.go

@@ -1,42 +0,0 @@
-package cache
-
-import (
-	"fmt"
-	"sync"
-
-	"github.com/xeipuuv/gojsonschema"
-)
-
-// SchemaCache is a cache for downloaded schemas, so each file is only retrieved once
-type SchemaCache struct {
-	sync.RWMutex
-	schemas map[string]*gojsonschema.Schema
-}
-
-// New creates a new cache for downloaded schemas
-func New() *SchemaCache {
-	return &SchemaCache{
-		schemas: map[string]*gojsonschema.Schema{},
-	}
-}
-
-// Key computes a key for a specific JSON schema from its Kind, the resource API Version, and the
-// Kubernetes version
-func Key(resourceKind, resourceAPIVersion, k8sVersion string) string {
-	return fmt.Sprintf("%s-%s-%s", resourceKind, resourceAPIVersion, k8sVersion)
-}
-
-// Get retrieves the JSON schema given a resource signature
-func (c *SchemaCache) Get(key string) (*gojsonschema.Schema, bool) {
-	c.RLock()
-	defer c.RUnlock()
-	schema, ok := c.schemas[key]
-	return schema, ok
-}
-
-// Set adds a JSON schema to the schema cache
-func (c *SchemaCache) Set(key string, schema *gojsonschema.Schema) {
-	c.Lock()
-	defer c.Unlock()
-	c.schemas[key] = schema
-}