FAB-10720 Persistence for new cc install package

This CR adds a way to persist a ChaincodeInstallPackage on the
filesystem.

Change-Id: I59c066ba7b7577904cc78ba34722c3851d51b97d
Signed-off-by: Will Lahti <wtlahti@us.ibm.com>

Author: wlahti

core/chaincode/persistence/mock/iowriter.go

@@ -0,0 +1,112 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package persistence
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/hyperledger/fabric/common/flogging"
+	"github.com/hyperledger/fabric/common/util"
+	"github.com/pkg/errors"
+)
+
+var logger = flogging.MustGetLogger("chaincode/persistence")
+
+// IOWriter defines the interface needed for adding/removing/checking for existence
+// of a specified file
+type IOWriter interface {
+	WriteFile(string, []byte, os.FileMode) error
+	Stat(string) (os.FileInfo, error)
+	Remove(name string) error
+}
+
+// FilesystemWriter is the production implementation of the IOWriter interface
+type FilesystemWriter struct {
+}
+
+// WriteFile writes a file to the filesystem
+func (f *FilesystemWriter) WriteFile(filename string, data []byte, perm os.FileMode) error {
+	return ioutil.WriteFile(filename, data, perm)
+}
+
+// Stat checks for existence of the file on the filesystem
+func (f *FilesystemWriter) Stat(name string) (os.FileInfo, error) {
+	return os.Stat(name)
+}
+
+// Remove removes a file from the filesystem - used for rolling back an in-flight
+// Save operation upon a failure
+func (f *FilesystemWriter) Remove(name string) error {
+	return os.Remove(name)
+}
+
+// Store holds the information needed for persisting a chaincode install package
+type Store struct {
+	Path   string
+	Writer IOWriter
+}
+
+// Save persists chaincode install package bytes with the given name
+// and version
+func (s *Store) Save(name, version string, ccInstallPkg []byte) error {
+	metadataJSON, err := toJSON(name, version)
+	if err != nil {
+		return err
+	}
+
+	hashString := hex.EncodeToString(util.ComputeSHA256(ccInstallPkg))
+	metadataPath := filepath.Join(s.Path, hashString+".json")
+	if _, err := s.Writer.Stat(metadataPath); err == nil {
+		return errors.Errorf("chaincode metadata already exists at %s", metadataPath)
+	}
+
+	ccInstallPkgPath := filepath.Join(s.Path, hashString+".bin")
+	if _, err := s.Writer.Stat(ccInstallPkgPath); err == nil {
+		return errors.Errorf("ChaincodeInstallPackage already exists at %s", ccInstallPkgPath)
+	}
+
+	if err := s.Writer.WriteFile(metadataPath, metadataJSON, 0600); err != nil {
+		return errors.Wrapf(err, "error writing metadata file to %s", metadataPath)
+	}
+
+	if err := s.Writer.WriteFile(ccInstallPkgPath, ccInstallPkg, 0600); err != nil {
+		err = errors.Wrapf(err, "error writing chaincode install package to %s", ccInstallPkgPath)
+		logger.Error(err.Error())
+
+		// need to roll back metadata write above on error
+		if err2 := s.Writer.Remove(metadataPath); err2 != nil {
+			logger.Errorf("error removing metadata file at %s: %s", metadataPath, err2)
+		}
+		return err
+	}
+
+	return nil
+}
+
+// ChaincodeMetadata holds the name and version of a chaincode
+type ChaincodeMetadata struct {
+	Name    string `json:"Name"`
+	Version string `json:"Version"`
+}
+
+func toJSON(name, version string) ([]byte, error) {
+	metadata := &ChaincodeMetadata{
+		Name:    name,
+		Version: version,
+	}
+
+	metadataBytes, err := json.Marshal(metadata)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to marshal name and version into JSON")
+	}
+
+	return metadataBytes, nil
+}

core/chaincode/persistence/persistence.go

@@ -0,0 +1,25 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package persistence_test
+
+import (
+	"testing"
+
+	"github.com/hyperledger/fabric/core/chaincode/persistence"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+//go:generate counterfeiter -o mock/iowriter.go -fake-name IOWriter . ioWriter
+type ioWriter interface {
+	persistence.IOWriter
+}
+
+func TestPersistence(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Persistence Suite")
+}