Analytics: allow more control over merging of document contexts

Signed-off-by: Richard Kosegi <richard.kosegi@gmail.com>

analytics/document_set.go

@@ -17,6 +17,7 @@ limitations under the License.
 package analytics
 
 import (
+	"errors"
 	"fmt"
 	"github.com/rkosegi/yaml-toolkit/dom"
 	"github.com/rkosegi/yaml-toolkit/k8s"
@@ -33,6 +34,10 @@ const (
 	wildcardTag = "*"
 )
 
+var (
+	ErrLayerAlreadyExists = errors.New("layer already exists")
+)
+
 var (
 	b           = dom.Builder()
 	defaultOpts = []AddLayerOpt{
@@ -60,6 +65,8 @@ type docContext struct {
 	doc dom.ContainerBuilder
 	// list of tags
 	tags []string
+	// function used to merge 2 contexts
+	mergeFn func(ctx *docContext, doc dom.ContainerBuilder) error
 }
 
 // DefaultFileDecoderProvider is FileDecoderProvider that uses file suffix to choose dom.DecoderFunc
@@ -82,6 +89,25 @@ func WithTags(tag ...string) AddLayerOpt {
 	}
 }
 
+// MergeTags does not consider newly added dom.ContainerBuilder, it just merges tags into existing context
+func MergeTags() AddLayerOpt {
+	return func(_ *documentSet, _ string, context *docContext) {
+		context.mergeFn = func(newCtx *docContext, doc dom.ContainerBuilder) error {
+			context.tags = utils.Unique(append(context.tags, newCtx.tags...))
+			return nil
+		}
+	}
+}
+
+// MustCreate ensures that layer does not already exist
+func MustCreate() AddLayerOpt {
+	return func(_ *documentSet, _ string, context *docContext) {
+		context.mergeFn = func(newCtx *docContext, doc dom.ContainerBuilder) error {
+			return ErrLayerAlreadyExists
+		}
+	}
+}
+
 func (ds *documentSet) applyOpts(name string, ctx *docContext, opts ...AddLayerOpt) *docContext {
 	for _, opt := range defaultOpts {
 		opt(ds, name, ctx)
@@ -92,31 +118,43 @@ func (ds *documentSet) applyOpts(name string, ctx *docContext, opts ...AddLayerO
 	return ctx
 }
 
-func (ds *documentSet) addContext(name string, doc dom.ContainerBuilder, ctx *docContext) {
-	ctx.doc = doc
-	ds.ctxMap[name] = ctx
+func (ds *documentSet) addContext(name string, doc dom.ContainerBuilder, newCtx *docContext) error {
+	existingCtx, exists := ds.ctxMap[name]
+	if exists {
+		if newCtx.mergeFn != nil {
+			err := newCtx.mergeFn(existingCtx, doc)
+			if err != nil {
+				return err
+			}
+		}
+		ds.ctxMap[name] = newCtx
+		return nil
+	} else {
+		newCtx.doc = doc
+		ds.ctxMap[name] = newCtx
+		return nil
+	}
 }
 
 func (ds *documentSet) newContext(name string, opts ...AddLayerOpt) *docContext {
 	return ds.applyOpts(name, &docContext{}, opts...)
 }
 
-func (ds *documentSet) AddDocument(name string, doc dom.ContainerBuilder, opts ...AddLayerOpt) {
-	ds.addContext(name, doc, ds.newContext(name, opts...))
+func (ds *documentSet) AddDocument(name string, doc dom.ContainerBuilder, opts ...AddLayerOpt) error {
+	return ds.addContext(name, doc, ds.newContext(name, opts...))
 }
 
-func (ds *documentSet) AddUnnamedDocument(doc dom.ContainerBuilder, opts ...AddLayerOpt) {
+func (ds *documentSet) AddUnnamedDocument(doc dom.ContainerBuilder, opts ...AddLayerOpt) error {
 	ds.unnamedLayerId++
-	ds.AddDocument(fmt.Sprintf("default__%d", ds.unnamedLayerId), doc, opts...)
+	return ds.AddDocument(fmt.Sprintf("default__%d", ds.unnamedLayerId), doc, opts...)
 }
 
 func (ds *documentSet) AddDocumentFromReader(name string, r io.Reader, dec dom.DecoderFunc, opts ...AddLayerOpt) error {
 	cb, err := b.FromReader(r, dec)
 	if err != nil {
 		return err
 	}
-	ds.addContext(name, cb, ds.newContext(name, opts...))
-	return nil
+	return ds.AddDocument(name, cb, opts...)
 }
 
 func (ds *documentSet) AddDocumentFromFile(file string, dec dom.DecoderFunc, opts ...AddLayerOpt) error {
@@ -164,9 +202,8 @@ func (ds *documentSet) AddPropertiesFromManifest(manifest string, opts ...AddLay
 	if err != nil {
 		return err
 	} else {
-		ds.AddDocument(manifest, doc.Document(), opts...)
+		return ds.AddDocument(manifest, doc.Document(), opts...)
 	}
-	return nil
 }
 
 func containsAnyOf(col []string, contains []string) bool {

analytics/document_set_test.go

@@ -48,3 +48,16 @@ func TestDocumentSetAdd(t *testing.T) {
 	assert.Nil(t, ds.NamedDocument("invalid"))
 	assert.NotNil(t, ds.NamedDocument("../testdata/cm2.yaml"))
 }
+
+func TestDocumentSetMergeTags(t *testing.T) {
+	ds := NewDocumentSet()
+	assert.NoError(t, ds.AddPropertiesFromManifest("../testdata/secret3.yaml", WithTags("prop1")))
+	assert.NoError(t, ds.AddPropertiesFromManifest("../testdata/secret3.yaml", WithTags("prop2"), MergeTags()))
+	assert.Equal(t, 3, len(ds.(*documentSet).ctxMap["../testdata/secret3.yaml"].tags))
+}
+
+func TestDocumentSetMustCreate(t *testing.T) {
+	ds := NewDocumentSet()
+	assert.NoError(t, ds.AddPropertiesFromManifest("../testdata/secret3.yaml", WithTags("prop1")))
+	assert.Error(t, ds.AddPropertiesFromManifest("../testdata/secret3.yaml", WithTags("prop2"), MustCreate()))
+}

analytics/types.go

@@ -41,10 +41,10 @@ type DocumentSet interface {
 	AsOne() dom.OverlayDocument
 
 	// AddDocument adds given document into documentSet.
-	AddDocument(name string, doc dom.ContainerBuilder, opts ...AddLayerOpt)
+	AddDocument(name string, doc dom.ContainerBuilder, opts ...AddLayerOpt) error
 
 	// AddUnnamedDocument adds document that has no particular name designation, one will be generated internally
-	AddUnnamedDocument(doc dom.ContainerBuilder, opts ...AddLayerOpt)
+	AddUnnamedDocument(doc dom.ContainerBuilder, opts ...AddLayerOpt) error
 
 	// AddDocumentFromFile calls AddDocumentFromFileWithDecoder with second argument set to DefaultFileDecoderProvider.
 	AddDocumentFromFile(file string, dec dom.DecoderFunc, opts ...AddLayerOpt) error