kopia/connection.go

package kopia

import (
	"errors"
	"fmt"

	"github.com/kopia/kopia/internal/config"
	"github.com/kopia/kopia/repo"
	"github.com/kopia/kopia/storage"
	"github.com/kopia/kopia/storage/caching"
	"github.com/kopia/kopia/storage/logging"
	"github.com/kopia/kopia/vault"
)

// Connection represents open connection to Vault and Repository.
type Connection struct {
	Vault      *vault.Vault
	Repository *repo.Repository
}

// ConnectionOptions specifies the behavior of Connection.
type ConnectionOptions struct {
	CredentialsCallback func() (vault.Credentials, error) // credentials required to open the vault, unless persisted

	TraceStorage      func(f string, args ...interface{})
	RepositoryOptions []repo.RepositoryOption
}

// Close closes the underlying Vault and Repository.
func (c *Connection) Close() error {
	if c.Vault != nil {
		c.Vault.Close()
		c.Vault = nil
	}

	if c.Repository != nil {
		c.Repository.Close()
		c.Repository = nil
	}

	return nil
}

// Open connects to the Vault and Repository specified in the specified configuration file.
func Open(configFile string, options *ConnectionOptions) (*Connection, error) {
	lc, err := config.LoadFromFile(configFile)
	if err != nil {
		return nil, err
	}

	var creds vault.Credentials
	if len(lc.VaultConnection.Key) > 0 {
		creds, err = vault.MasterKey(lc.VaultConnection.Key)
	} else {
		if options.CredentialsCallback == nil {
			return nil, errors.New("vault key not persisted and no credentials specified")
		}
		creds, err = options.CredentialsCallback()
	}

	if err != nil {
		return nil, fmt.Errorf("invalid vault credentials: %v", err)
	}

	rawVaultStorage, err := storage.NewStorage(lc.VaultConnection.ConnectionInfo)
	if err != nil {
		return nil, fmt.Errorf("cannot open vault storage: %v", err)
	}

	vaultStorage := rawVaultStorage

	if options.TraceStorage != nil {
		vaultStorage = logging.NewWrapper(vaultStorage, logging.Prefix("[VAULT] "), logging.Output(options.TraceStorage))
	}

	var conn Connection
	conn.Vault, err = vault.Open(vaultStorage, creds)
	if err != nil {
		rawVaultStorage.Close()
		return nil, fmt.Errorf("unable to open vault: %v", err)
	}

	var repositoryStorage storage.Storage

	if lc.RepoConnection == nil {
		repositoryStorage = rawVaultStorage
	} else {
		repositoryStorage, err = storage.NewStorage(*lc.RepoConnection)
		if err != nil {
			vaultStorage.Close()
			return nil, err
		}
	}

	if options.TraceStorage != nil {
		repositoryStorage = logging.NewWrapper(repositoryStorage, logging.Prefix("[STORAGE] "), logging.Output(options.TraceStorage))
	}

	if lc.Caching != nil {
		rs, err := caching.NewWrapper(repositoryStorage, lc.Caching)
		if err != nil {
			vaultStorage.Close()
			repositoryStorage.Close()
			return nil, err
		}
		repositoryStorage = rs
		if options.TraceStorage != nil {
			repositoryStorage = logging.NewWrapper(repositoryStorage, logging.Prefix("[CACHE] "), logging.Output(options.TraceStorage))
		}
	}

	conn.Repository, err = repo.New(repositoryStorage, conn.Vault.RepoConfig.Format)
	if err != nil {
		vaultStorage.Close()
		repositoryStorage.Close()
		return nil, err
	}

	return &conn, nil
}