feat(kuma-cp) save service's tags to header

CHANGELOG.md

@@ -1,6 +1,8 @@
 # CHANGELOG
 
 ## master
+* feat: save service's tags to header for L7-traffic
+  [#647](https://github.com/Kong/kuma/pull/647/files)
 * chore: the API root `/` now returns the hostname
   [#645](https://github.com/Kong/kuma/pull/645) 
 * feat: FaultInjection entity, support in API and `kumactl` 

pkg/xds/envoy/listeners/http_inbound_route_configurer.go

@@ -28,6 +28,7 @@ func (c *HttpInboundRouteConfigurer) Configure(filterChain *envoy_listener.Filte
 	routeName := envoy_names.GetInboundRouteName(c.service)
 	routeConfig, err := envoy_routes.NewRouteConfigurationBuilder().
 		Configure(envoy_routes.CommonRouteConfiguration(routeName)).
+		Configure(envoy_routes.ResetTagsHeader()).
 		Configure(envoy_routes.VirtualHost(envoy_routes.NewVirtualHostBuilder().
 			Configure(envoy_routes.CommonVirtualHost(c.service)).
 			Configure(envoy_routes.DefaultRoute(c.cluster)))).

pkg/xds/envoy/listeners/http_inbound_route_configurer_test.go

@@ -64,6 +64,8 @@ var _ = Describe("HttpInboundRouteConfigurer", func() {
                   - name: envoy.router
                   routeConfig:
                     name: inbound:backend
+                    requestHeadersToRemove:
+                    - x-kuma-tags
                     validateClusters: true
                     virtualHosts:
                     - domains:

pkg/xds/envoy/routes/reset_tags_header_configurer.go

@@ -0,0 +1,19 @@
+package routes
+
+import envoy_api_v2 "github.com/envoyproxy/go-control-plane/envoy/api/v2"
+
+// ResetTagsHeader adds x-kuma-tags header to the RequestHeadersToRemove list. x-kuma-tags header is planned to be used
+// internally, so we don't want to expose it to the destination application.
+func ResetTagsHeader() RouteConfigurationBuilderOpt {
+	return RouteConfigurationBuilderOptFunc(func(config *RouteConfigurationBuilderConfig) {
+		config.Add(&ResetTagsHeaderConfigurer{})
+	})
+}
+
+type ResetTagsHeaderConfigurer struct {
+}
+
+func (r *ResetTagsHeaderConfigurer) Configure(rc *envoy_api_v2.RouteConfiguration) error {
+	rc.RequestHeadersToRemove = append(rc.RequestHeadersToRemove, TagsHeaderName)
+	return nil
+}

pkg/xds/envoy/routes/reset_tags_header_configurer_test.go

@@ -0,0 +1,30 @@
+package routes_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	util_proto "github.com/Kong/kuma/pkg/util/proto"
+	"github.com/Kong/kuma/pkg/xds/envoy/routes"
+)
+
+var _ = Describe("ResetTagsHeaderConfigurer", func() {
+
+	It("should generate proper Envoy config", func() {
+		// when
+		routeConfiguration, err := routes.NewRouteConfigurationBuilder().
+			Configure(routes.ResetTagsHeader()).
+			Build()
+		// then
+		Expect(err).ToNot(HaveOccurred())
+
+		// when
+		actual, err := util_proto.ToYAML(routeConfiguration)
+		// then
+		Expect(err).ToNot(HaveOccurred())
+		// and
+		Expect(actual).To(MatchYAML(`
+            requestHeadersToRemove:
+              - x-kuma-tags`))
+	})
+})

pkg/xds/envoy/routes/tags_header_configurer.go

@@ -0,0 +1,46 @@
+package routes
+
+import (
+	"fmt"
+	"strings"
+
+	envoy_api_v2 "github.com/envoyproxy/go-control-plane/envoy/api/v2"
+	envoy_core "github.com/envoyproxy/go-control-plane/envoy/api/v2/core"
+
+	mesh_proto "github.com/Kong/kuma/api/mesh/v1alpha1"
+)
+
+const TagsHeaderName = "x-kuma-tags"
+
+func TagsHeader(tags mesh_proto.MultiValueTagSet) RouteConfigurationBuilderOpt {
+	return RouteConfigurationBuilderOptFunc(func(config *RouteConfigurationBuilderConfig) {
+		config.Add(&TagsHeaderConfigurer{
+			tags: tags,
+		})
+	})
+}
+
+type TagsHeaderConfigurer struct {
+	tags mesh_proto.MultiValueTagSet
+}
+
+func (t *TagsHeaderConfigurer) Configure(rc *envoy_api_v2.RouteConfiguration) error {
+	if len(t.tags) == 0 {
+		return nil
+	}
+	rc.RequestHeadersToAdd = append(rc.RequestHeadersToAdd, &envoy_core.HeaderValueOption{
+		Header: &envoy_core.HeaderValue{Key: TagsHeaderName, Value: serializeTags(t.tags)},
+	})
+	return nil
+}
+
+func serializeTags(tags mesh_proto.MultiValueTagSet) string {
+	var pairs []string
+	for _, key := range tags.Keys() {
+		pairs = append(pairs, fmt.Sprintf("%s=%s", key, strings.Join(tags.Values(key), ",")))
+	}
+	if len(pairs) == 0 {
+		return ""
+	}
+	return "&" + strings.Join(pairs, "&") + "&"
+}

pkg/xds/envoy/routes/tags_header_configurer_test.go

@@ -0,0 +1,53 @@
+package routes_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/ginkgo/extensions/table"
+	. "github.com/onsi/gomega"
+
+	mesh_proto "github.com/Kong/kuma/api/mesh/v1alpha1"
+	util_proto "github.com/Kong/kuma/pkg/util/proto"
+	"github.com/Kong/kuma/pkg/xds/envoy/routes"
+)
+
+var _ = Describe("TagsHeaderConfigurer", func() {
+
+	type testCase struct {
+		tags     mesh_proto.MultiValueTagSet
+		expected string
+	}
+
+	DescribeTable("should generate proper Envoy config",
+		func(given testCase) {
+			// when
+			routeConfiguration, err := routes.NewRouteConfigurationBuilder().
+				Configure(routes.TagsHeader(given.tags)).
+				Build()
+			// then
+			Expect(err).ToNot(HaveOccurred())
+
+			// when
+			actual, err := util_proto.ToYAML(routeConfiguration)
+			// then
+			Expect(err).ToNot(HaveOccurred())
+			// and
+			Expect(actual).To(MatchYAML(given.expected))
+		},
+		Entry("basic tags", testCase{
+			tags: map[string]map[string]bool{
+				"tag2": {"value21": true},
+				"tag3": {"value31": true, "value32": true, "value33": true},
+				"tag1": {"value11": true, "value12": true},
+			},
+			expected: `
+            requestHeadersToAdd:
+            - header:
+                key: x-kuma-tags
+                value: '&tag1=value11,value12&tag2=value21&tag3=value31,value32,value33&'`,
+		}),
+		Entry("empty tags", testCase{
+			tags:     map[string]map[string]bool{},
+			expected: `{}`,
+		}),
+	)
+})

pkg/xds/generator/proxy_template.go

@@ -224,12 +224,13 @@ func (g OutboundProxyGenerator) Generate(ctx xds_context.Context, proxy *model.P
 		})
 
 		// generate RDS resources
-		rdsResources, err := g.generateRds(protocol, outbound.Service, outboundRouteName, clusters)
+		rdsResources, err := g.generateRds(protocol, outbound.Service, outboundRouteName, clusters, proxy.Dataplane.Spec.Tags())
 		if err != nil {
 			return nil, err
 		}
 		resources.Add(rdsResources...)
 	}
+
 	return resources.List(), nil
 }
 
@@ -274,13 +275,14 @@ func (_ OutboundProxyGenerator) generateEds(ctx xds_context.Context, proxy *mode
 	return
 }
 
-func (_ OutboundProxyGenerator) generateRds(protocol mesh_core.Protocol, service string, outboundRouteName string, clusters []envoy_common.ClusterInfo) ([]*model.Resource, error) {
+func (_ OutboundProxyGenerator) generateRds(protocol mesh_core.Protocol, service string, outboundRouteName string, clusters []envoy_common.ClusterInfo, tags kuma_mesh.MultiValueTagSet) ([]*model.Resource, error) {
 	resources := &model.ResourceSet{}
 	switch protocol {
 	case mesh_core.ProtocolHTTP:
 		// generate RDS resource
 		routeConfiguration, err := envoy_routes.NewRouteConfigurationBuilder().
 			Configure(envoy_routes.CommonRouteConfiguration(outboundRouteName)).
+			Configure(envoy_routes.TagsHeader(tags)).
 			Configure(envoy_routes.VirtualHost(envoy_routes.NewVirtualHostBuilder().
 				Configure(envoy_routes.CommonVirtualHost(service)).
 				Configure(envoy_routes.DefaultRoute(clusters...)))).

pkg/xds/generator/testdata/inbound-proxy/3-envoy-config.golden.yaml

@@ -46,6 +46,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend1
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:

pkg/xds/generator/testdata/inbound-proxy/4-envoy-config.golden.yaml

@@ -48,6 +48,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend1
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:

pkg/xds/generator/testdata/inbound-proxy/5-envoy-config.golden.yaml

@@ -45,6 +45,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend1
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:

pkg/xds/generator/testdata/inbound-proxy/6-envoy-config.golden.yaml

@@ -47,6 +47,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend1
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:

pkg/xds/generator/testdata/inbound-proxy/7-envoy-config.golden.yaml

@@ -45,6 +45,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend1
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:
@@ -174,6 +176,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend3
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:

pkg/xds/generator/testdata/inbound-proxy/8-envoy-config.golden.yaml

@@ -47,6 +47,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend1
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:
@@ -180,6 +182,8 @@ resources:
                 - name: envoy.router
                 routeConfig:
                   name: inbound:backend3
+                  requestHeadersToRemove:
+                    - x-kuma-tags
                   validateClusters: true
                   virtualHosts:
                   - domains:

pkg/xds/generator/testdata/outbound-proxy/09.envoy.golden.yaml

@@ -172,6 +172,10 @@ resources:
   resource:
     '@type': type.googleapis.com/envoy.api.v2.RouteConfiguration
     name: outbound:api-http
+    requestHeadersToAdd:
+    - header:
+        key: x-kuma-tags
+        value: '&service=gateway&'
     validateClusters: true
     virtualHosts:
     - domains:

pkg/xds/generator/testdata/outbound-proxy/10.envoy.golden.yaml

@@ -290,6 +290,10 @@ resources:
   resource:
     '@type': type.googleapis.com/envoy.api.v2.RouteConfiguration
     name: outbound:api-http
+    requestHeadersToAdd:
+    - header:
+        key: x-kuma-tags
+        value: '&service=web&'
     validateClusters: true
     virtualHosts:
     - domains:

pkg/xds/generator/testdata/profile-source/3-envoy-config.golden.yaml

@@ -81,6 +81,8 @@ resources:
           - name: envoy.router
           routeConfig:
             name: inbound:backend
+            requestHeadersToRemove:
+              - x-kuma-tags
             validateClusters: true
             virtualHosts:
             - domains:

pkg/xds/generator/testdata/profile-source/4-envoy-config.golden.yaml

@@ -111,6 +111,8 @@ resources:
           - name: envoy.router
           routeConfig:
             name: inbound:backend
+            requestHeadersToRemove:
+              - x-kuma-tags
             validateClusters: true
             virtualHosts:
             - domains: