render: fix selectors (#394)

Without this patch selectors don't work as expected.  This patch
fixes selectors such that each --selector flag value configures one
selector containing multiple positive or negative label matchers.

Result:

Render build plans for cluster dev or cluster test.  Note the use of two
flags indicating logical OR.

    holos render platform --selector cluster=test --selector cluster=dev
    rendered external-secrets for cluster test in 299.897542ms
    rendered external-secrets for cluster dev in 299.9225ms
    rendered external-secrets-crds for cluster test in 667.6075ms
    rendered external-secrets-crds for cluster dev in 708.126541ms
    rendered platform in 708.795625ms

Render build plans for prod clusters that are not customer facing.  Note
the use of one selector with comma separated labels.

    holos render platform --selector "tier=prod,scope!=customer"

internal/builder/platform.go

@@ -16,7 +16,7 @@ import (
 // platform.
 type PlatformOpts struct {
 	Fn          func(context.Context, int, holos.Component) error
-	Selector    holos.Selector
+	Selectors   holos.Selectors
 	Concurrency int
 	InfoEnabled bool
 }
@@ -31,7 +31,7 @@ type Platform struct {
 func (p *Platform) Build(ctx context.Context, opts PlatformOpts) error {
 	limit := max(opts.Concurrency, 1)
 	parentStart := time.Now()
-	components := p.Select(opts.Selector)
+	components := p.Select(opts.Selectors...)
 	total := len(components)
 
 	g, ctx := errgroup.WithContext(ctx)

internal/cli/render/render.go

@@ -45,8 +45,8 @@ func newPlatform(cfg *holos.Config, feature holos.Flagger) *cobra.Command {
 	cmd.Flags().StringVar(&platform, "platform", "./platform", "platform directory path")
 	var extractYAMLs holos.StringSlice
 	cmd.Flags().Var(&extractYAMLs, "extract-yaml", "data file paths to extract and unify with the platform config")
-	var selector holos.Selector
-	cmd.Flags().VarP(&selector, "selector", "l", "label selector (e.g. label==string,label!=string)")
+	var selectors holos.Selectors
+	cmd.Flags().VarP(&selectors, "selector", "l", "label selector (e.g. label==string,label!=string)")
 	tagMap := make(holos.TagMap)
 	cmd.Flags().VarP(&tagMap, "inject", "t", tagHelp)
 
@@ -75,7 +75,7 @@ func newPlatform(cfg *holos.Config, feature holos.Flagger) *cobra.Command {
 		}
 		opts := builder.PlatformOpts{
 			Fn:          makeComponentRenderFunc(cmd.ErrOrStderr(), prefixArgs, tagMap.Tags()),
-			Selector:    selector,
+			Selectors:   selectors,
 			Concurrency: concurrency,
 			InfoEnabled: true,
 		}

internal/cli/show.go

@@ -70,8 +70,8 @@ func newShowBuildPlanCmd() (cmd *cobra.Command) {
 	cmd.Flags().Var(&extractYAMLs, "extract-yaml", "data file paths to extract and unify with the platform config")
 	var format string
 	cmd.Flags().StringVar(&format, "format", "yaml", "yaml or json format")
-	var selector holos.Selector
-	cmd.Flags().VarP(&selector, "selector", "l", "label selector (e.g. label==string,label!=string)")
+	var selectors holos.Selectors
+	cmd.Flags().VarP(&selectors, "selector", "l", "label selector (e.g. label==string,label!=string)")
 	tagMap := make(holos.TagMap)
 	cmd.Flags().VarP(&tagMap, "inject", "t", "set the value of a cue @tag field from a key=value pair")
 	var concurrency int
@@ -102,7 +102,7 @@ func newShowBuildPlanCmd() (cmd *cobra.Command) {
 
 		platformOpts := builder.PlatformOpts{
 			Fn:          makeBuildFunc(encoder, buildPlanOpts),
-			Selector:    selector,
+			Selectors:   selectors,
 			Concurrency: concurrency,
 		}
 

internal/holos/types.go

@@ -107,6 +107,28 @@ func (e *EnvFlagger) Flag(name feature) bool {
 
 type Labels map[string]string
 
+type Selectors []Selector
+
+// String implements the flag.Value interface.
+func (s *Selectors) String() string {
+	return fmt.Sprint(*s)
+}
+
+// Type implements the pflag.Value interface and describes the type.
+func (s *Selectors) Type() string {
+	return "selectors"
+}
+
+// Set implements the flag.Value interface.
+func (s *Selectors) Set(value string) error {
+	selector := Selector{}
+	if err := selector.Set(value); err != nil {
+		return err
+	}
+	*s = append(*s, selector)
+	return nil
+}
+
 type Selector struct {
 	Positive map[string]string
 	Negative map[string]string
@@ -118,14 +140,9 @@ func (s *Selector) IsSelected(labels Labels) bool {
 		return true // Nil selector selects everything
 	}
 
-	if len(s.Positive) == 0 && len(s.Negative) == 0 {
-		return true // Empty selector selects everything
-	}
-
 	// Check positive matches
 	for k, v := range s.Positive {
-		val, ok := labels[k]
-		if !ok || v != val {
+		if val, ok := labels[k]; !ok || v != val {
 			return false
 		}
 	}
@@ -251,15 +268,18 @@ func (y *yamlEncoder) Close() error {
 	return errors.Wrap(y.enc.Close())
 }
 
-// IsSelected returns true if all selectors select the given labels or no
+// IsSelected returns true if any one selector selects the given labels or no
 // selectors are given.
 func IsSelected(labels Labels, selectors ...Selector) bool {
+	if len(selectors) == 0 {
+		return true
+	}
 	for _, selector := range selectors {
-		if !selector.IsSelected(labels) {
-			return false
+		if selector.IsSelected(labels) {
+			return true
 		}
 	}
-	return true
+	return false
 }
 
 type orderedEncoder struct {

version/embedded/patch

@@ -1 +1 @@
-3
+4