'wdcli backup': Rework backup process

This commit reworks the backup process to dynamically find the list of
components.

internal/component/sql/backup.go

@@ -0,0 +1,35 @@
+package sql
+
+import (
+	"errors"
+	"os"
+
+	"github.com/tkw1536/goprogram/stream"
+)
+
+var errSQLBackup = errors.New("SQLBackup: Mysqldump returned non-zero exit code")
+
+func (*SQL) BackupName() string {
+	return "sql.sql"
+}
+
+// Backup makes a backup of all SQL databases into the path dest.
+func (sql *SQL) Backup(io stream.IOStream, dest string) error {
+	// open the file, TODO: Outsource this to context
+	writer, err := os.Create(dest)
+	if err != nil {
+		return err
+	}
+	defer writer.Close()
+
+	// run sqldump
+	io = io.Streams(writer, nil, nil, 0).NonInteractive()
+	code, err := sql.Stack().Exec(io, "sql", "mysqldump", "--all-databases")
+	if err != nil {
+		return err
+	}
+	if code != 0 {
+		return errSQLBackup
+	}
+	return nil
+}

internal/component/sql/database.go

@@ -59,10 +59,8 @@ func (sql SQL) OpenBookkeeping(silent bool) (*gorm.DB, error) {
 	return table, nil
 }
 
-var errSQLBackup = errors.New("SQLBackup: Mysqldump returned non-zero exit code")
-
-// Backup makes a backup of the sql database into dest.
-func (sql SQL) Backup(io stream.IOStream, dest io.Writer, database string) error {
+// Snapshot makes a backup of the sql database into dest.
+func (sql SQL) Snapshot(io stream.IOStream, dest io.Writer, database string) error {
 	io = io.Streams(dest, nil, nil, 0).NonInteractive()
 
 	code, err := sql.Stack().Exec(io, "sql", "mysqldump", "--databases", database)
@@ -75,20 +73,6 @@ func (sql SQL) Backup(io stream.IOStream, dest io.Writer, database string) error
 	return nil
 }
 
-// BackupAll makes a backup of all sql databases
-func (sql SQL) BackupAll(io stream.IOStream, dest io.Writer) error {
-	io = stream.NewIOStream(dest, io.Stderr, nil, 0)
-
-	code, err := sql.Stack().Exec(io, "sql", "mysqldump", "--all-databases")
-	if err != nil {
-		return err
-	}
-	if code != 0 {
-		return errSQLBackup
-	}
-	return nil
-}
-
 // OpenShell executes a mysql shell command
 func (sql SQL) OpenShell(io stream.IOStream, argv ...string) (int, error) {
 	return sql.Stack().Exec(io, "sql", "mysql", argv...)

internal/component/sql/sql.go

@@ -22,13 +22,13 @@ func (SQL) Name() string {
 	return "sql"
 }
 
-//go:embed all:stack
+//go:embed all:sql
 var resources embed.FS
 
-func (ssh SQL) Stack() component.Installable {
-	return ssh.ComponentBase.MakeStack(component.Installable{
+func (ssh SQL) Stack() component.StackWithResources {
+	return ssh.ComponentBase.MakeStack(component.StackWithResources{
 		Resources:   resources,
-		ContextPath: "stack",
+		ContextPath: "sql",
 
 		MakeDirsPerm: fs.ModeDir | fs.ModePerm,
 		MakeDirs: []string{