feat(cmd): detect changed in configuration

Signed-off-by: AtomicFS <vojtech.vesely@9elements.com>

Author: AtomicFS

cmd/firmware-action/recipes/config.go

@@ -16,6 +16,7 @@ import (
 
 	"dagger.io/dagger"
 	"github.com/9elements/firmware-action/cmd/firmware-action/container"
+	"github.com/9elements/firmware-action/cmd/firmware-action/filesystem"
 	"github.com/9elements/firmware-action/cmd/firmware-action/logging"
 	"github.com/go-playground/validator/v10"
 )
@@ -313,6 +314,18 @@ type FirmwareModule interface {
 	buildFirmware(ctx context.Context, client *dagger.Client) error
 }
 
+// ===============================
+//  Functions for FirmwareModules
+// ===============================
+
+// FilenameForFirmwareModule is used to take a user-defined module name and make it into filename, removing
+// all problematic characters
+func FilenameForFirmwareModule(name string) string {
+	// For example:
+	//   "Coreboot Example" should return "Coreboot_Example.json"
+	return fmt.Sprintf("%s.json", filesystem.Filenamify(name))
+}
+
 // ======================
 //  Functions for Config
 // ======================

cmd/firmware-action/recipes/recipes.go

@@ -16,6 +16,7 @@ import (
 
 	"dagger.io/dagger"
 	"github.com/9elements/firmware-action/cmd/firmware-action/filesystem"
+	"github.com/google/go-cmp/cmp"
 	"github.com/heimdalr/dag"
 )
 
@@ -34,8 +35,13 @@ var (
 var (
 	// ContainerWorkDir specifies directory in container used as work directory
 	ContainerWorkDir = "/workdir"
+	// StatusDir is directory for temporary files generated by firmware-action to aid change detection
+	StatusDir = ".firmware-action"
 	// TimestampsDir specifies directory for timestamps to detect changes in sources
-	TimestampsDir = ".firmware-action/timestamps"
+	TimestampsDir = filepath.Join(StatusDir, "timestamps")
+	// CompiledConfigsDir specifies directory for successfully compiled module configurations to detect changes in
+	//   configuration
+	CompiledConfigsDir = filepath.Join(StatusDir, "configs")
 )
 
 func forestAddVertex(forest *dag.DAG, key string, value FirmwareModule, dependencies [][]string) ([][]string, error) {
@@ -179,13 +185,17 @@ func Execute(ctx context.Context, target string, config *Config) error {
 	if err != nil {
 		return err
 	}
+	err = os.MkdirAll(CompiledConfigsDir, os.ModePerm)
+	if err != nil {
+		return err
+	}
 
 	// Find requested target
 	modules := config.AllModules()
 	if _, ok := modules[target]; ok {
-		// Check if up-to-date
-		// Either returns time, or zero time and error
-		// zero time means there was no previous run
+		// Check for any change in source files
+		//   Either returns time, or zero time and error
+		//   zero time means there was no previous run
 		timestampFile := filepath.Join(TimestampsDir, fmt.Sprintf("%s.txt", target))
 		lastRun, _ := filesystem.LoadLastRunTime(timestampFile)
 
@@ -199,19 +209,47 @@ func Execute(ctx context.Context, target string, config *Config) error {
 			}
 		}
 
+		// Check for any change in configuration
+		//   I did consider to save only the small struct related to each module, but it was
+		//   proving to be far too much work. Instead we save the whole configuration file (for each module
+		//   separately) and only compare the relevant modules between these two configurations
+		oldConfigPath := filepath.Join(CompiledConfigsDir, FilenameForFirmwareModule(target))
+		err = filesystem.CheckFileExists(oldConfigPath)
+		changedConfig := false
+		if errors.Is(err, os.ErrExist) {
+			oldConfig, err := ReadConfig(oldConfigPath)
+			if err != nil {
+				return err
+			}
+			oldModules := oldConfig.AllModules()
+			changedConfig = !cmp.Equal(modules[target], oldModules[target])
+		}
+		slog.Warn("Changes detected",
+			slog.Bool("sources", changesDetected),
+			slog.Bool("config", changedConfig),
+		)
+
 		// Check if output directory already exist
 		// We want to skip build if the output directory exists and is not empty
 		// If it is empty, then just continue with the building
 		// If changes in sources were detected, re-build
 		_, errExists := os.Stat(modules[target].GetOutputDir())
 		empty, _ := IsDirEmpty(modules[target].GetOutputDir())
 		if errExists == nil && !empty {
-			if changesDetected {
+			if changesDetected || changedConfig {
 				// If any of the sources changed, we need to rebuild
 				os.RemoveAll(modules[target].GetOutputDir())
 			} else {
 				// Is already up-to-date
 				slog.Warn(fmt.Sprintf("Target '%s' is up-to-date, skipping build", target))
+
+				// It is possible that the timestamp of old config files are missing
+				//   for example user deleted them, CI does not cache them, ...
+				//   but at the same time the output directory exists with all the artifacts
+				// The 'override' is false, meaning that if files already exist, they will not
+				//   be overridden
+				saveCheckpointTimeStamp(timestampFile, false)
+				saveCheckpointConfig(oldConfigPath, config, false)
 				return ErrBuildUpToDate
 			}
 		}
@@ -246,14 +284,38 @@ func Execute(ctx context.Context, target string, config *Config) error {
 		// Build the module
 		err = modules[target].buildFirmware(ctx, client)
 		if err == nil {
-			// On success update the timestamp
-			_ = filesystem.SaveCurrentRunTime(timestampFile)
+			// On successful build, save timestamp and current configuration
+			saveCheckpointTimeStamp(timestampFile, true)
+			saveCheckpointConfig(oldConfigPath, config, true)
 		}
 		return err
 	}
 	return ErrTargetMissing
 }
 
+func saveCheckpointTimeStamp(timestampFilePath string, override bool) {
+	// On success update the timestamp
+	err := filesystem.CheckFileExists(timestampFilePath)
+	if errors.Is(err, os.ErrNotExist) || override {
+		slog.Debug("Saving timestamp")
+		_ = filesystem.SaveCurrentRunTime(timestampFilePath)
+	}
+}
+
+func saveCheckpointConfig(configPath string, config *Config, override bool) {
+	// On success update the old configuration
+	err := filesystem.CheckFileExists(configPath)
+	if errors.Is(err, os.ErrNotExist) || override {
+		slog.Debug("Saving copy of configuration file")
+		err = WriteConfig(configPath, config)
+		if err != nil {
+			slog.Warn("Failed to create a snapshot of configuration for detecting future changes",
+				slog.Any("error", err),
+			)
+		}
+	}
+}
+
 // NormalizeArchitecture will translate various architecture strings into expected format
 func NormalizeArchitecture(arch string) string {
 	archMap := map[string]string{