Move the default schema cache to the home directory

pkg/kubectl/cmd/util/factory.go

@@ -24,6 +24,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"os/user"
 	"path"
 	"strconv"
 
@@ -308,9 +309,63 @@ type schemaClient interface {
 	Get() *client.Request
 }
 
+func recursiveSplit(dir string) []string {
+	parent, file := path.Split(dir)
+	if len(parent) == 0 {
+		return []string{file}
+	}
+	return append(recursiveSplit(parent[:len(parent)-1]), file)
+}
+
+func substituteUserHome(dir string) (string, error) {
+	if len(dir) == 0 || dir[0] != '~' {
+		return dir, nil
+	}
+	parts := recursiveSplit(dir)
+	if len(parts[0]) == 1 {
+		parts[0] = os.Getenv("HOME")
+	} else {
+		usr, err := user.Lookup(parts[0][1:])
+		if err != nil {
+			return "", err
+		}
+		parts[0] = usr.HomeDir
+	}
+	return path.Join(parts...), nil
+}
+
+func writeSchemaFile(schemaData []byte, cacheDir, cacheFile, prefix, groupVersion string) error {
+	if err := os.MkdirAll(path.Join(cacheDir, prefix, groupVersion), 0755); err != nil {
+		return err
+	}
+	tmpFile, err := ioutil.TempFile(cacheDir, "schema")
+	if err != nil {
+		// If we can't write, keep going.
+		if os.IsPermission(err) {
+			return nil
+		}
+		return err
+	}
+	if _, err := io.Copy(tmpFile, bytes.NewBuffer(schemaData)); err != nil {
+		return err
+	}
+	if err := os.Link(tmpFile.Name(), cacheFile); err != nil {
+		// If we can't write due to file existing, or permission problems, keep going.
+		if os.IsExist(err) || os.IsPermission(err) {
+			return nil
+		}
+		return err
+	}
+	return nil
+}
+
 func getSchemaAndValidate(c schemaClient, data []byte, prefix, groupVersion, cacheDir string) (err error) {
 	var schemaData []byte
-	cacheFile := path.Join(cacheDir, prefix, groupVersion, schemaFileName)
+	fullDir, err := substituteUserHome(cacheDir)
+	if err != nil {
+		return err
+	}
+	cacheFile := path.Join(fullDir, prefix, groupVersion, schemaFileName)
 
 	if len(cacheDir) != 0 {
 		if schemaData, err = ioutil.ReadFile(cacheFile); err != nil && !os.IsNotExist(err) {
@@ -326,17 +381,7 @@ func getSchemaAndValidate(c schemaClient, data []byte, prefix, groupVersion, cac
 			return err
 		}
 		if len(cacheDir) != 0 {
-			if err = os.MkdirAll(path.Join(cacheDir, prefix, groupVersion), 0755); err != nil {
-				return err
-			}
-			tmpFile, err := ioutil.TempFile(cacheDir, "schema")
-			if err != nil {
-				return err
-			}
-			if _, err := io.Copy(tmpFile, bytes.NewBuffer(schemaData)); err != nil {
-				return err
-			}
-			if err := os.Link(tmpFile.Name(), cacheFile); err != nil && !os.IsExist(err) {
+			if err := writeSchemaFile(schemaData, fullDir, cacheFile, prefix, groupVersion); err != nil {
 				return err
 			}
 		}

pkg/kubectl/cmd/util/factory_test.go

@@ -22,6 +22,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
+	"os/user"
 	"path"
 	"sort"
 	"strings"
@@ -302,3 +303,32 @@ func TestValidateCachesSchema(t *testing.T) {
 		t.Errorf("unexpected cache file error: %v", err)
 	}
 }
+
+func TestSubstitueUser(t *testing.T) {
+	usr, _ := user.Current()
+	tests := []struct {
+		input     string
+		expected  string
+		expectErr bool
+	}{
+		{input: "~/foo", expected: path.Join(os.Getenv("HOME"), "foo")},
+		{input: "~" + usr.Username + "/bar", expected: usr.HomeDir + "/bar"},
+		{input: "/foo/bar", expected: "/foo/bar"},
+		{input: "~doesntexit/bar", expectErr: true},
+	}
+	for _, test := range tests {
+		output, err := substituteUserHome(test.input)
+		if test.expectErr {
+			if err == nil {
+				t.Error("unexpected non-error")
+			}
+			continue
+		}
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if output != test.expected {
+			t.Errorf("expected: %s, saw: %s", test.expected, output)
+		}
+	}
+}

pkg/kubectl/cmd/util/helpers.go

@@ -279,7 +279,7 @@ func GetFlagDuration(cmd *cobra.Command, flag string) time.Duration {
 
 func AddValidateFlags(cmd *cobra.Command) {
 	cmd.Flags().Bool("validate", true, "If true, use a schema to validate the input before sending it")
-	cmd.Flags().String("schema-cache-dir", "/tmp/kubectl.schema", "If non-empty, load/store cached API schemas in this directory, default is '/tmp/kubectl.schema'")
+	cmd.Flags().String("schema-cache-dir", fmt.Sprintf("~/%s/%s", clientcmd.RecommendedHomeDir, clientcmd.RecommendedSchemaName), fmt.Sprintf("If non-empty, load/store cached API schemas in this directory, default is '$HOME/%s/%s'", clientcmd.RecommendedHomeDir, clientcmd.RecommendedSchemaName))
 }
 
 func ReadConfigDataFromReader(reader io.Reader, source string) ([]byte, error) {