Add transaction attribute to actions

docker-compose.yml

@@ -16,6 +16,6 @@ services:
     ports:
       - "8081:8081"
     environment:
-      - DATABASE_URL=postgres://krab:secret@pg:5432/krab?sslmode=disable
+      - PGWEB_DATABASE_URL=postgres://krab:secret@pg:5432/krab?sslmode=disable
     depends_on:
       - pg

krab/action.go

@@ -9,7 +9,6 @@ import (
 )
 
 // Action represents custom action to execute.
-//
 type Action struct {
 	krabhcl.Source
 
@@ -18,7 +17,8 @@ type Action struct {
 
 	Arguments *Arguments
 
-	SQL string
+	SQL         string
+	Transaction bool // wrap operation in transaction
 }
 
 func (a *Action) Addr() krabhcl.Addr {
@@ -37,6 +37,10 @@ var schemaAction = &hcl.BodySchema{
 			Name:     "sql",
 			Required: true,
 		},
+		{
+			Name:     "transaction",
+			Required: false,
+		},
 	},
 }
 
@@ -47,6 +51,7 @@ func (a *Action) DecodeHCL(ctx *hcl.EvalContext, block *hcl.Block) error {
 	a.Namespace = block.Labels[0]
 	a.RefName = block.Labels[1]
 	a.Arguments = &Arguments{}
+	a.Transaction = true
 
 	content, diags := block.Body.Content(schemaAction)
 	if diags.HasErrors() {
@@ -76,6 +81,14 @@ func (a *Action) DecodeHCL(ctx *hcl.EvalContext, block *hcl.Block) error {
 			}
 			a.SQL = val
 
+		case "transaction":
+			expr := krabhcl.Expression{Expr: v.Expr, EvalContext: ctx}
+			val, err := expr.Bool()
+			if err != nil {
+				return err
+			}
+			a.Transaction = val
+
 		default:
 			return fmt.Errorf("Unknown attribute `%s` for `%s` block", k, block.Type)
 		}

krab/cmd_action.go

@@ -9,6 +9,7 @@ import (
 	"github.com/ohkrab/krab/krabhcl"
 	"github.com/ohkrab/krab/krabtpl"
 	"github.com/ohkrab/krab/tpls"
+	"github.com/pkg/errors"
 )
 
 // CmdAction returns migration status information.
@@ -51,7 +52,19 @@ func (c *CmdAction) run(ctx context.Context, db krabdb.DB, inputs NamedInputs) (
 	c.Action.ToSQL(&sb)
 	sql := tpl.Render(sb.String())
 
-	_, err := db.ExecContext(ctx, sql)
+	tx, err := db.NewTx(ctx, c.Action.Transaction)
+	if err != nil {
+		return result, errors.Wrap(err, "failed to create transaction")
+	}
+	_, err = tx.ExecContext(ctx, sql)
+	if err != nil {
+		tx.Rollback()
+		return result, errors.Wrap(err, "action failed")
+	}
+	err = tx.Commit()
+	if err != nil {
+		return result, errors.Wrap(err, "failed to commit transaction")
+	}
 
 	return result, err
 }