feat: add generate config loading

generate/config.go

@@ -0,0 +1,97 @@
+// Copyright 2022 Mineiros GmbH
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package generate
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"github.com/mineiros-io/terramate/config"
+	"github.com/mineiros-io/terramate/stack"
+	"github.com/rs/zerolog/log"
+)
+
+// StackCfg represents code generation configuration for a stack.
+type StackCfg struct {
+	BackendCfgFilename string
+	LocalsFilename     string
+}
+
+const (
+	// BackendCfgFilename is the name of the terramate generated tf file for backend configuration.
+	BackendCfgFilename = "_gen_backend_cfg.tm.tf"
+
+	// LocalsFilename is the name of the terramate generated tf file for exported locals.
+	LocalsFilename = "_gen_locals.tm.tf"
+)
+
+// LoadStackCfg loads code generation configuration for the given stack.
+func LoadStackCfg(root string, stack stack.S) (StackCfg, error) {
+	return loadStackCfg(root, stack.AbsPath())
+}
+
+func loadStackCfg(root string, configdir string) (StackCfg, error) {
+	logger := log.With().
+		Str("action", "loadStackCfg()").
+		Str("root", root).
+		Str("configDir", configdir).
+		Logger()
+
+	logger.Trace().Msg("Check if still inside project root.")
+
+	if !strings.HasPrefix(configdir, root) {
+		logger.Trace().Msg("Outside project root, returning default config")
+		return StackCfg{
+			BackendCfgFilename: BackendCfgFilename,
+			LocalsFilename:     LocalsFilename,
+		}, nil
+	}
+
+	logger.Trace().Msg("loading config.")
+
+	parsedConfig, found, err := config.TryLoadRootConfig(configdir)
+	if err != nil {
+		return StackCfg{}, fmt.Errorf("loading stack config: %v", err)
+	}
+
+	if !found {
+		logger.Trace().Msg("config file not found.")
+		return loadStackCfg(root, filepath.Dir(configdir))
+	}
+
+	logger.Trace().Msg("loaded config.")
+
+	if parsedConfig.Terramate.RootConfig.Generate == nil {
+		logger.Trace().Msg("terramate.config.generate block not found.")
+		return loadStackCfg(root, filepath.Dir(configdir))
+	}
+
+	logger.Trace().Msg("terramate.config.generate found.")
+
+	gen := parsedConfig.Terramate.RootConfig.Generate
+
+	return StackCfg{
+		BackendCfgFilename: optstr(gen.BackendCfgFilename, BackendCfgFilename),
+		LocalsFilename:     optstr(gen.LocalsFilename, LocalsFilename),
+	}, nil
+}
+
+func optstr(val string, def string) string {
+	if val == "" {
+		return def
+	}
+	return val
+}