feat: add file values provider

assembly/local/Taskfile.yaml

@@ -1,8 +1,12 @@
 version: '3'
 
 tasks:
-  nginx:
+  run:
+    desc: run as helm plugin directly from go code
+    # examples:
+    #   task local:run -- simple --chart bitnami/nginx --file ./testdata/bitnami.nginx.yaml
+    #   task local:run -- simple --chart bitnami/nginx --stdin < <(cat ./testdata/bitnami.nginx.yaml)
     env:
       HELM_PLUGINS: "{{ .INJECT_HELM_PLUGINS }}"
     cmds:
-      - cat ./testdata/bitnami.nginx.yaml | helm local {{ .CLI_ARGS }}
+      - helm local {{ .CLI_ARGS }}

cmd/helm-clean-values/simple.go

@@ -4,13 +4,16 @@ import (
 	"fmt"
 
 	"github.com/sarcaustech/helm-clean-values/pkg/core"
+	"github.com/sarcaustech/helm-clean-values/pkg/core/adapters/providers/file"
 	"github.com/sarcaustech/helm-clean-values/pkg/core/adapters/providers/helm"
 	"github.com/sarcaustech/helm-clean-values/pkg/core/adapters/providers/stdin"
 	"github.com/sarcaustech/helm-clean-values/pkg/core/adapters/selectors/simple"
 	"github.com/urfave/cli/v2"
 	"gopkg.in/yaml.v3"
 )
 
+var simpleInputMethod string // centralize once more than one selector cmd
+
 var simpleCmd = &cli.Command{
 	Name:  "simple",
 	Usage: "detect unused helm values by comparing with the chart's default values",
@@ -19,27 +22,58 @@ var simpleCmd = &cli.Command{
 			Name:  "stdin",
 			Usage: "read input values from STDIN",
 		},
+		&cli.StringFlag{
+			Name:    "file",
+			Aliases: []string{"f"},
+			Usage:   "filepath to read input values from",
+		},
 		&cli.StringFlag{
 			Name:  "chart",
 			Usage: "helm prompt to get the chart",
 		},
 	},
 	Before: func(cCtx *cli.Context) error {
-		if !cCtx.Bool("stdin") {
+		methods := 0
+
+		if cCtx.Bool("stdin") {
+			methods++
+			simpleInputMethod = "stdin"
+		}
+		if cCtx.String("file") != "" {
+			methods++
+			simpleInputMethod = "file"
+		}
+
+		if methods > 1 {
+			return fmt.Errorf("too input values provided, expected only one method")
+		}
+		if methods == 0 {
 			return fmt.Errorf("no input values provided")
 		}
+
 		return nil
 	},
 	Action: func(cCtx *cli.Context) (err error) {
 
-		inputProvider := stdin.ValuesProvider{}
-		referenceProvider := helm.ValuesProvider{
+		var inputProvider core.ValuesProvider
+		switch simpleInputMethod {
+		case "stdin":
+			inputProvider = &stdin.ValuesProvider{}
+		case "file":
+			inputProvider = &file.ValuesProvider{
+				Path: cCtx.String("file"),
+			}
+		default:
+			return fmt.Errorf("unknown input method %s", simpleInputMethod)
+		}
+
+		referenceProvider := &helm.ValuesProvider{
 			BinaryPath: cCtx.String("helm-bin"),
 			Prompt:     cCtx.String("chart"),
 		}
-		selector := simple.Selector{}
+		selector := &simple.Selector{}
 
-		cleanedValues, err := core.Run(&inputProvider, &referenceProvider, &selector)
+		cleanedValues, err := core.Run(inputProvider, referenceProvider, selector)
 		if err != nil {
 			return err
 		}

pkg/core/adapters/providers/file/file.go

@@ -0,0 +1,26 @@
+package file
+
+import (
+	"fmt"
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+type ValuesProvider struct {
+	Path string
+}
+
+func (p *ValuesProvider) Values() (map[string]interface{}, error) {
+	bytes, err := os.ReadFile(p.Path)
+	if err != nil {
+		return nil, fmt.Errorf("cannot not read file %s: %w", p.Path, err)
+	}
+
+	var data map[string]interface{}
+	err = yaml.Unmarshal(bytes, &data)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse file contents to YAML %s: %w", p.Path, err)
+	}
+	return data, nil
+}