From 7e4bb365e6e7faf5520cf154a922786a1ea4e0dd Mon Sep 17 00:00:00 2001
From: Niklas Wagner <n.wagner@finatix.de>
Date: Wed, 24 Mar 2021 12:16:55 +0100
Subject: [PATCH] Allows ordering of Custom Resources

Signed-off-by: Niklas Wagner <n.wagner@finatix.de>
---
 pkg/releaseutil/kind_sorter.go     | 46 +++++++++++++++++++++---------
 pkg/releaseutil/manifest.go        |  3 ++
 pkg/releaseutil/manifest_sorter.go | 43 ++++++++++++++++++++++++++--
 3 files changed, 76 insertions(+), 16 deletions(-)

diff --git a/pkg/releaseutil/kind_sorter.go b/pkg/releaseutil/kind_sorter.go
index a340dfc29..89289c5de 100644
--- a/pkg/releaseutil/kind_sorter.go
+++ b/pkg/releaseutil/kind_sorter.go
@@ -108,12 +108,12 @@ var UninstallOrder KindSortOrder = []string{
 // sort manifests by kind.
 //
 // Results are sorted by 'ordering', keeping order of items with equal kind/priority
-func sortManifestsByKind(manifests []Manifest, ordering KindSortOrder) []Manifest {
-	sort.SliceStable(manifests, func(i, j int) bool {
-		return lessByKind(manifests[i], manifests[j], manifests[i].Head.Kind, manifests[j].Head.Kind, ordering)
+func sortManifestsByKind(m []Manifest, ordering KindSortOrder) []Manifest {
+	sort.SliceStable(m, func(i, j int) bool {
+		return lessByKind(m[i], m[j], m[i].Head.Kind, m[j].Head.Kind, m[i].InstallBefore, m[j].InstallBefore, ordering)
 	})
 
-	return manifests
+	return m
 }
 
 // sort hooks by kind, using an out-of-place sort to preserve the input parameters.
@@ -122,20 +122,15 @@ func sortManifestsByKind(manifests []Manifest, ordering KindSortOrder) []Manifes
 func sortHooksByKind(hooks []*release.Hook, ordering KindSortOrder) []*release.Hook {
 	h := hooks
 	sort.SliceStable(h, func(i, j int) bool {
-		return lessByKind(h[i], h[j], h[i].Kind, h[j].Kind, ordering)
+		return lessByKind(h[i], h[j], h[i].Kind, h[j].Kind, nil, nil, ordering)
 	})
 
 	return h
 }
 
-func lessByKind(a interface{}, b interface{}, kindA string, kindB string, o KindSortOrder) bool {
-	ordering := make(map[string]int, len(o))
-	for v, k := range o {
-		ordering[k] = v
-	}
-
-	first, aok := ordering[kindA]
-	second, bok := ordering[kindB]
+func lessByKind(a interface{}, b interface{}, kindA string, kindB string, beforeA []string, beforeB []string, o KindSortOrder) bool {
+	first, aok := installOrderIndex(kindA, beforeA, o)
+	second, bok := installOrderIndex(kindB, beforeB, o)
 
 	if !aok && !bok {
 		// if both are unknown then sort alphabetically by kind, keep original order if same kind
@@ -154,3 +149,28 @@ func lessByKind(a interface{}, b interface{}, kindA string, kindB string, o Kind
 	// sort different kinds, keep original order if same priority
 	return first < second
 }
+
+// installOrderIndex returns the lowest index number of all beforeKinds
+func installOrderIndex(kind string, beforeKinds []string, o KindSortOrder) (int, bool) {
+	ordering := make(map[string]int, len(o))
+	for v, k := range o {
+		ordering[k] = v
+	}
+
+	orderIndex, foundIndex := ordering[kind]
+
+	// reset orderIndex for unknown resources
+	if !foundIndex {
+		orderIndex = len(o)
+	}
+
+	for _, kind := range beforeKinds {
+		i, ok := ordering[kind]
+		if ok && i < orderIndex {
+			foundIndex = true
+			// set orderIndex 1 BEFORE the actual index, so it get executed BEFORE it
+			orderIndex = i - 1
+		}
+	}
+	return orderIndex, foundIndex
+}
diff --git a/pkg/releaseutil/manifest.go b/pkg/releaseutil/manifest.go
index 0b04a4599..34dd16be0 100644
--- a/pkg/releaseutil/manifest.go
+++ b/pkg/releaseutil/manifest.go
@@ -23,6 +23,9 @@ import (
 	"strings"
 )
 
+// InstallOrderAnnotation the annotation that allows manipulating the install order of custom resources
+const InstallOrderAnnotation = "helm.sh/install-before"
+
 // SimpleHead defines what the structure of the head of a manifest file
 type SimpleHead struct {
 	Version  string `json:"apiVersion"`
diff --git a/pkg/releaseutil/manifest_sorter.go b/pkg/releaseutil/manifest_sorter.go
index e83414500..8f5f61263 100644
--- a/pkg/releaseutil/manifest_sorter.go
+++ b/pkg/releaseutil/manifest_sorter.go
@@ -32,9 +32,10 @@ import (
 
 // Manifest represents a manifest file, which has a name and some content.
 type Manifest struct {
-	Name    string
-	Content string
-	Head    *SimpleHead
+	Name          string
+	Content       string
+	Head          *SimpleHead
+	InstallBefore []string
 }
 
 // manifestFile represents a file that contains a manifest.
@@ -155,6 +156,30 @@ func (file *manifestFile) sort(result *result) error {
 			continue
 		}
 
+		installBeforeKinds, ok := entry.Metadata.Annotations[InstallOrderAnnotation]
+		// InstallOrderAnnotation is only supported for unknown Kinds e.g. Custom Resources
+		if ok && isKnownKind(entry.Kind) {
+			log.Printf("info: %v annotation is not supported for Kind %v", InstallOrderAnnotation, entry.Kind)
+		} else if ok {
+			var installBefore []string
+			for _, kind := range strings.Split(installBeforeKinds, ",") {
+				kind = strings.TrimSpace(kind)
+				if isKnownKind(kind) {
+					installBefore = append(installBefore, kind)
+				} else {
+					log.Printf("info: skipping unknown install-before kind: %q", kind)
+				}
+			}
+
+			result.generic = append(result.generic, Manifest{
+				Name:          file.path,
+				Content:       m,
+				Head:          &entry,
+				InstallBefore: installBefore,
+			})
+			continue
+		}
+
 		hookTypes, ok := entry.Metadata.Annotations[release.HookAnnotation]
 		if !ok {
 			result.generic = append(result.generic, Manifest{
@@ -231,3 +256,15 @@ func operateAnnotationValues(entry SimpleHead, annotation string, operate func(p
 		}
 	}
 }
+
+// isKnownKind returns true if the given kind exists in the InstallOrder or UninstallOrder
+func isKnownKind(kind string) bool {
+	knownKinds := append(InstallOrder, UninstallOrder...)
+
+	for _, kk := range knownKinds {
+		if kk == kind {
+			return true
+		}
+	}
+	return false
+}