feat: add logic for shared annotation (#6)

* port over existing pr

* handle templating + shared services

* this works

* clarifying comments
this version works

* one less todo

* cleanup

* chose original

kontrol-service/constants/constants.go

@@ -0,0 +1,5 @@
+package constants
+
+const (
+	SharedVersionVersionString = "shared"
+)

kontrol-service/engine/docker.go

@@ -146,6 +146,11 @@ func generateClusterTopology(serviceConfigs []apitypes.ServiceConfig, ingressCon
 			clusterTopologyService.IsExternal = true
 		}
 
+		isShared, ok := serviceAnnotations["kardinal.dev.service/shared"]
+		if ok && isShared == "true" {
+			clusterTopologyService.IsShared = true
+		}
+
 		// Service plugin?
 		sPlugins, ok := serviceAnnotations["kardinal.dev.service/plugins"]
 		if ok {

kontrol-service/engine/flow/dev_flow.go

@@ -2,6 +2,7 @@ package flow
 
 import (
 	"fmt"
+	"kardinal.kontrol-service/constants"
 
 	"github.com/kurtosis-tech/stacktrace"
 
@@ -66,6 +67,28 @@ func CreateDevFlow(pluginRunner *plugins.PluginRunner, baseClusterTopologyMaybeW
 		}
 	}
 
+	// TODO(shared-annotation) - we could store "shared" versions somewhere so that the pointers are the same
+	// if we do that then the render work around isn't necessary
+	// perhaps top sort this; currently the following is possible
+	// postgres is marked as shared, we mark its parent "cartservice" as shared
+	// cartservice then happens in the loop and we try again (currently we don't as we check if version isn't shared)
+	for _, service := range topology.Services {
+		if service.IsShared && service.Version != "prod" && service.Version != constants.SharedVersionVersionString {
+			logrus.Infof("Marking service '%v' as shared, current version '%v'", service.ServiceID, service.Version)
+			originalVersion := service.Version
+			service.Version = constants.SharedVersionVersionString
+			service.OriginalVersionIfShared = originalVersion
+
+			if !service.IsHTTP() {
+				logrus.Infof("Service '%v' isn't http; marking its parents as shared", service.ServiceID)
+				err := markParentsAsShared(&topology, service)
+				if err != nil {
+					return nil, err
+				}
+			}
+		}
+	}
+
 	// Update service dependencies
 	for i, dependency := range topologyRef.ServiceDependencies {
 		if dependency.Service.Version == "prod" {
@@ -87,6 +110,28 @@ func CreateDevFlow(pluginRunner *plugins.PluginRunner, baseClusterTopologyMaybeW
 	return topologyRef, nil
 }
 
+func markParentsAsShared(topology *resolved.ClusterTopology, service *resolved.Service) error {
+	parents := topology.FindImmediateParents(service)
+	for _, parent := range parents {
+		if parent.Version == constants.SharedVersionVersionString {
+			continue
+		}
+		logrus.Infof("Marking parent '%v' as shared, current verson '%s'", parent.ServiceID, parent.Version)
+		parent.IsShared = true
+		originalVersion := parent.Version
+		parent.Version = constants.SharedVersionVersionString
+		parent.OriginalVersionIfShared = originalVersion
+
+		if !parent.IsHTTP() {
+			err := markParentsAsShared(topology, parent)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 func applyPatch(
 	pluginRunner *plugins.PluginRunner,
 	topology *resolved.ClusterTopology,

kontrol-service/engine/flow/render.go

@@ -2,6 +2,7 @@ package flow
 
 import (
 	"fmt"
+	"kardinal.kontrol-service/constants"
 	"strings"
 
 	"github.com/samber/lo"
@@ -80,8 +81,15 @@ func RenderClusterResources(clusterTopology *resolved.ClusterTopology, namespace
 
 	logrus.Infof("have total of %d envoy filters", len(envoyFilters))
 
+	sharedServiceBackupVersions := map[string][]string{}
+	for _, service := range clusterTopology.Services {
+		if service.IsShared && service.Version == constants.SharedVersionVersionString {
+			logrus.Infof("Found original version '%v' for service '%v'", service.OriginalVersionIfShared, service.ServiceID)
+			sharedServiceBackupVersions[service.ServiceID] = append(sharedServiceBackupVersions[service.ServiceID], service.OriginalVersionIfShared)
+		}
+	}
 	// TODO: make it to use a list of Ingresses
-	gatewayFilter := getEnvoyFilterForGateway(servicesAgainstVersions, versionsAgainstExtHost)
+	gatewayFilter := getEnvoyFilterForGateway(servicesAgainstVersions, versionsAgainstExtHost, sharedServiceBackupVersions)
 	envoyFilters = append(envoyFilters, *gatewayFilter)
 
 	return types.ClusterResources{
@@ -220,14 +228,21 @@ func getVirtualService(serviceID string, services []*resolved.Service, namespace
 }
 
 func getDestinationRule(serviceID string, services []*resolved.Service, namespace string) *istioclient.DestinationRule {
-	subsets := lo.Map(services, func(service *resolved.Service, _ int) *v1alpha3.Subset {
-		return &v1alpha3.Subset{
-			Name: service.Version,
-			Labels: map[string]string{
-				"version": service.Version,
-			},
-		}
-	})
+	// TODO(shared-annotation) - we could store "shared" versions somewhere so that the pointers are the same
+	// if we do that then the render work around isn't necessary
+	subsets := lo.UniqBy(
+		lo.Map(services, func(service *resolved.Service, _ int) *v1alpha3.Subset {
+			return &v1alpha3.Subset{
+				Name: service.Version,
+				Labels: map[string]string{
+					"version": service.Version,
+				},
+			}
+		}),
+		func(subset *v1alpha3.Subset) string {
+			return subset.Name
+		},
+	)
 
 	return &istioclient.DestinationRule{
 		TypeMeta: metav1.TypeMeta{
@@ -497,8 +512,8 @@ func getAuthorizationPolicy(service *resolved.Service, namespace string) *securi
 	}
 }
 
-func getEnvoyFilterForGateway(servicesAgainstVersions map[string][]string, serviceAndVersionAgainstExtHost map[string]string) *istioclient.EnvoyFilter {
-	luaScript := generateDynamicLuaScript(servicesAgainstVersions, serviceAndVersionAgainstExtHost)
+func getEnvoyFilterForGateway(servicesAgainstVersions map[string][]string, serviceAndVersionAgainstExtHost map[string]string, serviceAgainstBackupVersions map[string][]string) *istioclient.EnvoyFilter {
+	luaScript := generateDynamicLuaScript(servicesAgainstVersions, serviceAndVersionAgainstExtHost, serviceAgainstBackupVersions)
 
 	return &istioclient.EnvoyFilter{
 		TypeMeta: metav1.TypeMeta{
@@ -554,7 +569,7 @@ func getEnvoyFilterForGateway(servicesAgainstVersions map[string][]string, servi
 	}
 }
 
-func generateDynamicLuaScript(servicesAgainstVersions map[string][]string, versionAgainstExtHost map[string]string) string {
+func generateDynamicLuaScript(servicesAgainstVersions map[string][]string, versionAgainstExtHost map[string]string, serviceAgainstBackupVersions map[string][]string) string {
 	var setRouteCalls strings.Builder
 
 	// Helper function to add a setRoute call
@@ -574,11 +589,13 @@ func generateDynamicLuaScript(servicesAgainstVersions map[string][]string, versi
 `, service, destination))
 	}
 
-	// This is the one we are interested in
 	// For prod host all goes to prod
 	// For non prod host we add a non prod mapping for the non prod service and everything else falls back
 	for service, versions := range servicesAgainstVersions {
 		for _, version := range versions {
+			if version == constants.SharedVersionVersionString {
+				continue
+			}
 			setRouteCalls.WriteString(fmt.Sprintf(`
     if hostname == "%s" then`, versionAgainstExtHost[version]))
 			destination := fmt.Sprintf("%s-%s", service, version)
@@ -588,6 +605,18 @@ func generateDynamicLuaScript(servicesAgainstVersions map[string][]string, versi
 		}
 	}
 
+	// we handle shared versions separately by finding host markings for original version
+	for service, originalVersions := range serviceAgainstBackupVersions {
+		for _, originalVersion := range originalVersions {
+			setRouteCalls.WriteString(fmt.Sprintf(`
+    if hostname == "%s" then`, versionAgainstExtHost[originalVersion]))
+			destination := fmt.Sprintf("%s-%s", service, constants.SharedVersionVersionString)
+			addSetRouteCall(service, destination)
+			setRouteCalls.WriteString(`
+    end`)
+		}
+	}
+
 	// this gets consumed by the virtual source route for the gateway
 	for version, extHost := range versionAgainstExtHost {
 		destination := fmt.Sprintf("%s-%s", extHost, version)

kontrol-service/types/cluster_topology/resolved/core.go

@@ -22,13 +22,15 @@ type ClusterTopology struct {
 }
 
 type Service struct {
-	ServiceID       string                 `json:"serviceID"`
-	Version         string                 `json:"version"`
-	ServiceSpec     *corev1.ServiceSpec    `json:"serviceSpec"`
-	DeploymentSpec  *appsv1.DeploymentSpec `json:"deploymentSpec"`
-	IsExternal      bool                   `json:"isExternal"`
-	IsStateful      bool                   `json:"isStateful"`
-	StatefulPlugins []*StatefulPlugin      `json:"statefulPlugins"`
+	ServiceID               string                 `json:"serviceID"`
+	Version                 string                 `json:"version"`
+	ServiceSpec             *corev1.ServiceSpec    `json:"serviceSpec"`
+	DeploymentSpec          *appsv1.DeploymentSpec `json:"deploymentSpec"`
+	IsExternal              bool                   `json:"isExternal"`
+	IsStateful              bool                   `json:"isStateful"`
+	StatefulPlugins         []*StatefulPlugin      `json:"statefulPlugins"`
+	IsShared                bool                   `json:"isShared"`
+	OriginalVersionIfShared string                 `json:"originalVersionIfShared"`
 }
 
 type ServiceDependency struct {