add DUMP_OVERLAYS_TO env var

README.md

@@ -74,7 +74,6 @@ be supported in the future.
         "https://$GITLAB_TOKEN@gitlab.noris.net/mcs/components/cuegen/wekan.git?ref=v6.71-mcs.0",
       ]
       debug: false                       // print some info useful for debugging
-      dumpOverlays: false                // dump overlays for debugging
     }
 
 ## Environment Variables
@@ -83,6 +82,7 @@ Some environment variables can help working with cuegen:
     CUEGEN_DEBUG              turn on debug output with "true"
     CUEGEN_HTTP_PASSWORD      password for git authentication
     CUEGEN_HTTP_USERNAME      username for git authentication
+    DUMP_OVERLAYS_TO          directory to dump overlays to (debug only)
     SOPS_AGE_KEY              age key for decryption
     SOPS_AGE_KEY_FILE         age key file for decryption
     YQ_PRETTYPRINT            !="": run yaml output thru `yq -P`
@@ -200,7 +200,8 @@ Load all files from directory `scripts` as key/values into `configMap.scripts.da
   * `v0.7.2`  - internal cleanup
   * `v0.8.0`  - allow remote cuegen directories, rm kustomize plugin support
   * `v0.9.0`  - upgrade cue to v0.6.0
-  * `v0.10.0` - add YQ_PRETTYPRINT to filter output thru `yq -P`
+  * `v0.10.0` - add `YQ_PRETTYPRINT` to filter output thru `yq -P`
+  * `v0.11.0` - add `DUMP_OVERLAYS_TO` to dump overlays to directory (debug)
 
 [CUE]:         https://cuelang.org
 [SOPS]:        https://github.com/mozilla/sops

internal/app/schema.cue

@@ -4,6 +4,5 @@ cuegen: close({
 	checkPaths?: [ ...string]
 	secretDataPath: *"" | string
 	debug:          *false | bool
-	dumpOverlays:   *false | bool
 	components?: [string, ...]
 })

internal/cuegen/cuegen.go

@@ -252,8 +252,13 @@ func (cg Cuegen) buildLoadConfig() (*load.Config, error) {
 					if cg.Debug {
 						log.Printf("        * %v -> %v", filename, path)
 					}
-					if cg.DumpOverlays {
-						os.WriteFile(overlayFilename, data, 0644)
+					if cg.DumpOverlaysTo != "" {
+						path := filepath.Join(cg.DumpOverlaysTo, overlayFilename)
+						err := os.WriteFile(path, data, 0644)
+						if err != nil {
+							return err
+						}
+						fmt.Printf(">>> dumped overlay to %v\n", overlayFilename)
 					}
 				} else {
 					if cg.Debug {

internal/cuegen/main.go

@@ -40,7 +40,6 @@ type Config struct {
 	} `yaml:"metadata"`
 	Components     []string `yaml:"components"`
 	Debug          bool     `yaml:"debug"`
-	DumpOverlays   bool     `yaml:"dumpOverlays"`
 	ObjectsPath    string   `yaml:"objectsPath"`
 	SecretDataPath string   `yaml:"secretDataPath"`
 	ChartRoot      string
@@ -65,7 +64,7 @@ type Cuegen struct {
 	SecretDataPath string
 	CheckPaths     []string
 	ChartRoot      string
-	DumpOverlays   bool
+	DumpOverlaysTo string
 	RootFS         *fs.FS
 }
 
@@ -93,10 +92,16 @@ func Exec(config Config) error {
 		ObjectsPath:    config.ObjectsPath,
 		ChartRoot:      config.ChartRoot,
 		SecretDataPath: config.SecretDataPath,
-		DumpOverlays:   config.DumpOverlays,
 		RootFS:         config.RootFS,
 	}
 
+	if dumpDir := os.Getenv("DUMP_OVERLAYS_TO"); dumpDir != "" && strings.HasPrefix(dumpDir, "/") {
+		if _, err := os.Stat(dumpDir); err != nil {
+			return fmt.Errorf("Exec: DUMP_OVERLAYS_TO: %v", err)
+		}
+		cg.DumpOverlaysTo = dumpDir
+	}
+
 	if config.CheckPath != "" {
 		cg.CheckPaths = []string{config.CheckPath}
 	}

tests/local/components-dump.txtar

@@ -1,15 +1,17 @@
 ### components-dump.txtar
 
 # components: dump overlays
-exec cuegen chart
-exec find
-stdout overlay-ORBY4AOZPH--a.cue
-stdout overlay-CUUTIGWCVW--b.cue
-cmp chart/overlay-ORBY4AOZPH--a.cue comp_a/a.cue
-cmp chart/overlay-CUUTIGWCVW--b.cue comp_b/b.cue
+
+exec mkdir OUT
+exec bash '-c' 'DUMP_OVERLAYS_TO=$WORK/OUT cuegen chart'
+stdout 'dumped overlay to overlay-CUUTIGWCVW--b.cue'
+stdout 'dumped overlay to overlay-remoteRootFS--a.cue'
+stdout 'dumped overlay to overlay-ORBY4AOZPH--a.cue'
+
+cmp OUT/overlay-ORBY4AOZPH--a.cue comp_a/a.cue
+cmp OUT/overlay-CUUTIGWCVW--b.cue comp_b/b.cue
 
 -- chart/cuegen.yaml --
-dumpOverlays: true
 components:
     - ../comp_a
     - ../comp_b