Add session flag to cookie config

agent/proxycfg/testing.go

@@ -1286,6 +1286,11 @@ func setupTestVariationConfigEntriesAndSnapshot(
 							FieldValue: "chocolate-chip",
 							Terminal:   true,
 						},
+						{
+							Field:        "cookie",
+							FieldValue:   "chocolate-chip",
+							CookieConfig: &structs.CookieConfig{Session: true},
+						},
 						{
 							Field:      "header",
 							FieldValue: "x-user-id",

agent/structs/config_entry_discoverychain.go

@@ -882,9 +882,14 @@ func (e *ServiceResolverConfigEntry) Validate() error {
 			if hp.FieldValue != "" && hp.Field == "" {
 				return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: FieldValue requires a Field to apply to", i)
 			}
-			if hp.CookieConfig != nil && hp.Field != HashPolicyCookie {
+			if hp.CookieConfig != nil {
+				if hp.Field != HashPolicyCookie {
 					return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: cookie_config provided for %q", i, hp.Field)
 				}
+				if hp.CookieConfig.Session && hp.CookieConfig.TTL != 0*time.Second {
+					return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: a session cookie cannot have an associated TTL", i)
+				}
+			}
 		}
 	}
 
@@ -1087,7 +1092,10 @@ type HashPolicy struct {
 // CookieConfig contains configuration for the "cookie" hash policy type.
 // This is specified to have Envoy generate a cookie for a client on its first request.
 type CookieConfig struct {
-	// TTL for generated cookies
+	// Generates a session cookie with no expiration.
+	Session bool `json:",omitempty"`
+
+	// TTL for generated cookies. Cannot be specified for session cookies.
 	TTL time.Duration `json:",omitempty"`
 
 	// The path to set for the cookie

agent/structs/config_entry_discoverychain_test.go

@@ -656,7 +656,7 @@ func TestServiceResolverConfigEntry_LoadBalancer(t *testing.T) {
 			validateErr: `HashPolicies specified for non-hash-based Policy`,
 		},
 		{
-			name: "empty policy with hash policy",
+			name: "cookie config with header policy",
 			entry: &ServiceResolverConfigEntry{
 				Kind: ServiceResolver,
 				Name: "test",
@@ -677,7 +677,28 @@ func TestServiceResolverConfigEntry_LoadBalancer(t *testing.T) {
 			validateErr: `cookie_config provided for "header"`,
 		},
 		{
-			name: "empty policy with hash policy",
+			name: "cannot generate session cookie with ttl",
+			entry: &ServiceResolverConfigEntry{
+				Kind: ServiceResolver,
+				Name: "test",
+				LoadBalancer: &LoadBalancer{
+					Policy: LBPolicyMaglev,
+					HashPolicies: []HashPolicy{
+						{
+							Field:      HashPolicyCookie,
+							FieldValue: "good-cookie",
+							CookieConfig: &CookieConfig{
+								Session: true,
+								TTL:     10 * time.Second,
+							},
+						},
+					},
+				},
+			},
+			validateErr: `a session cookie cannot have an associated TTL`,
+		},
+		{
+			name: "valid cookie policy",
 			entry: &ServiceResolverConfigEntry{
 				Kind: ServiceResolver,
 				Name: "test",

agent/structs/config_entry_test.go

@@ -531,6 +531,156 @@ func TestDecodeConfigEntry(t *testing.T) {
 				Name: "main",
 			},
 		},
+		{
+			name: "service-resolver: envoy hash lb kitchen sink",
+			snake: `
+				kind = "service-resolver"
+				name = "main"
+				load_balancer = {
+					policy = "ring_hash"
+					ring_hash_config = {
+						minimum_ring_size = 1
+						maximum_ring_size = 2
+					}
+					hash_policies = [
+						{
+							field = "cookie"
+							field_value = "good-cookie"
+							cookie_config = {
+								ttl = "1s"
+								path = "/oven"
+							}
+							terminal = true
+						},
+						{
+							field = "cookie"
+							field_value = "less-good-cookie"
+							cookie_config = {
+								session = true
+								path = "/toaster"
+							}
+							terminal = true
+						},
+						{
+							field = "header"
+							field_value = "x-user-id"
+						},
+						{
+							source_ip = true
+						}
+					]
+				}
+			`,
+			camel: `
+				Kind = "service-resolver"
+				Name = "main"
+				LoadBalancer = {
+					Policy = "ring_hash"
+					RingHashConfig = {
+						MinimumRingSize = 1
+						MaximumRingSize = 2
+					}
+					HashPolicies = [
+						{
+							Field = "cookie"
+							FieldValue = "good-cookie"
+							CookieConfig = {
+								TTL = "1s"
+								Path = "/oven"
+							}
+							Terminal = true
+						},
+						{
+							Field = "cookie"
+							FieldValue = "less-good-cookie"
+							CookieConfig = {
+								Session = true
+								Path = "/toaster"
+							}
+							Terminal = true
+						},
+						{
+							Field = "header"
+							FieldValue = "x-user-id"
+						},
+						{
+							SourceIP = true
+						}
+					]
+				}
+			`,
+			expect: &ServiceResolverConfigEntry{
+				Kind: "service-resolver",
+				Name: "main",
+				LoadBalancer: &LoadBalancer{
+					Policy: LBPolicyRingHash,
+					RingHashConfig: &RingHashConfig{
+						MinimumRingSize: 1,
+						MaximumRingSize: 2,
+					},
+					HashPolicies: []HashPolicy{
+						{
+							Field:      HashPolicyCookie,
+							FieldValue: "good-cookie",
+							CookieConfig: &CookieConfig{
+								TTL:  1 * time.Second,
+								Path: "/oven",
+							},
+							Terminal: true,
+						},
+						{
+							Field:      HashPolicyCookie,
+							FieldValue: "less-good-cookie",
+							CookieConfig: &CookieConfig{
+								Session: true,
+								Path:    "/toaster",
+							},
+							Terminal: true,
+						},
+						{
+							Field:      HashPolicyHeader,
+							FieldValue: "x-user-id",
+						},
+						{
+							SourceIP: true,
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "service-resolver: envoy least request kitchen sink",
+			snake: `
+				kind = "service-resolver"
+				name = "main"
+				load_balancer = {
+					policy = "least_request"
+					least_request_config = {
+						choice_count = 2
+					}
+				}
+			`,
+			camel: `
+				Kind = "service-resolver"
+				Name = "main"
+				LoadBalancer = {
+					Policy = "least_request"
+					LeastRequestConfig = {
+						ChoiceCount = 2
+					}
+				}
+			`,
+			expect: &ServiceResolverConfigEntry{
+				Kind: "service-resolver",
+				Name: "main",
+				LoadBalancer: &LoadBalancer{
+					Policy: LBPolicyLeastRequest,
+					LeastRequestConfig: &LeastRequestConfig{
+						ChoiceCount: 2,
+					},
+				},
+			},
+		},
 		{
 			name: "ingress-gateway: kitchen sink",
 			snake: `

agent/xds/routes.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net"
 	"strings"
+	"time"
 
 	envoy "github.com/envoyproxy/go-control-plane/envoy/api/v2"
 	envoyroute "github.com/envoyproxy/go-control-plane/envoy/api/v2/route"
@@ -614,8 +615,16 @@ func injectLBToRouteAction(lb *structs.LoadBalancer, action *envoyroute.RouteAct
 				Name: policy.FieldValue,
 			}
 			if policy.CookieConfig != nil {
-				cookie.Ttl = ptypes.DurationProto(policy.CookieConfig.TTL)
 				cookie.Path = policy.CookieConfig.Path
+
+				if policy.CookieConfig.TTL != 0*time.Second {
+					cookie.Ttl = ptypes.DurationProto(policy.CookieConfig.TTL)
+				}
+
+				// Envoy will generate a session cookie if the ttl is present and zero.
+				if policy.CookieConfig.Session {
+					cookie.Ttl = ptypes.DurationProto(0 * time.Second)
+				}
 			}
 			result = append(result, &envoyroute.RouteAction_HashPolicy{
 				PolicySpecifier: &envoyroute.RouteAction_HashPolicy_Cookie_{

agent/xds/routes_test.go

@@ -376,6 +376,62 @@ func TestEnvoyLBConfig_InjectToRouteAction(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "non-zero session ttl gets zeroed out",
+			lb: &structs.LoadBalancer{
+				Policy: structs.LBPolicyMaglev,
+				HashPolicies: []structs.HashPolicy{
+					{
+						Field:      structs.HashPolicyCookie,
+						FieldValue: "oatmeal",
+						CookieConfig: &structs.CookieConfig{
+							TTL:     10 * time.Second,
+							Session: true,
+						},
+					},
+				},
+			},
+			expected: envoyroute.RouteAction{
+				HashPolicy: []*envoyroute.RouteAction_HashPolicy{
+					{
+						PolicySpecifier: &envoyroute.RouteAction_HashPolicy_Cookie_{
+							Cookie: &envoyroute.RouteAction_HashPolicy_Cookie{
+								Name: "oatmeal",
+								Ttl:  ptypes.DurationProto(0 * time.Second),
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "zero value ttl omitted if not session cookie",
+			lb: &structs.LoadBalancer{
+				Policy: structs.LBPolicyMaglev,
+				HashPolicies: []structs.HashPolicy{
+					{
+						Field:      structs.HashPolicyCookie,
+						FieldValue: "oatmeal",
+						CookieConfig: &structs.CookieConfig{
+							Path: "/oven",
+						},
+					},
+				},
+			},
+			expected: envoyroute.RouteAction{
+				HashPolicy: []*envoyroute.RouteAction_HashPolicy{
+					{
+						PolicySpecifier: &envoyroute.RouteAction_HashPolicy_Cookie_{
+							Cookie: &envoyroute.RouteAction_HashPolicy_Cookie{
+								Name: "oatmeal",
+								Path: "/oven",
+								Ttl:  nil,
+							},
+						},
+					},
+				},
+			},
+		},
 		{
 			name: "source addr",
 			lb: &structs.LoadBalancer{
@@ -417,6 +473,14 @@ func TestEnvoyLBConfig_InjectToRouteAction(t *testing.T) {
 							Path: "/oven",
 						},
 					},
+					{
+						Field:      structs.HashPolicyCookie,
+						FieldValue: "chocolate-chip",
+						CookieConfig: &structs.CookieConfig{
+							Session: true,
+							Path:    "/oven",
+						},
+					},
 					{
 						Field:      structs.HashPolicyHeader,
 						FieldValue: "special-header",
@@ -443,6 +507,15 @@ func TestEnvoyLBConfig_InjectToRouteAction(t *testing.T) {
 							},
 						},
 					},
+					{
+						PolicySpecifier: &envoyroute.RouteAction_HashPolicy_Cookie_{
+							Cookie: &envoyroute.RouteAction_HashPolicy_Cookie{
+								Name: "chocolate-chip",
+								Ttl:  ptypes.DurationProto(0 * time.Second),
+								Path: "/oven",
+							},
+						},
+					},
 					{
 						PolicySpecifier: &envoyroute.RouteAction_HashPolicy_Header_{
 							Header: &envoyroute.RouteAction_HashPolicy_Header{

agent/xds/testdata/routes/connect-proxy-lb-in-resolver.envoy-1-12-x.golden

@@ -36,6 +36,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/connect-proxy-lb-in-resolver.envoy-1-13-x.golden

@@ -36,6 +36,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/connect-proxy-lb-in-resolver.envoy-1-14-x.golden

@@ -36,6 +36,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/connect-proxy-lb-in-resolver.envoy-1-15-x.golden

@@ -36,6 +36,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/ingress-lb-in-resolver.envoy-1-12-x.golden

@@ -37,6 +37,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/ingress-lb-in-resolver.envoy-1-13-x.golden

@@ -37,6 +37,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/ingress-lb-in-resolver.envoy-1-14-x.golden

@@ -37,6 +37,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

agent/xds/testdata/routes/ingress-lb-in-resolver.envoy-1-15-x.golden

@@ -37,6 +37,12 @@
                     },
                     "terminal": true
                   },
+                  {
+                    "cookie": {
+                      "name": "chocolate-chip",
+                      "ttl": "0s"
+                    }
+                  },
                   {
                     "header": {
                       "headerName": "x-user-id"

api/config_entry_discoverychain.go

@@ -269,7 +269,10 @@ type HashPolicy struct {
 // CookieConfig contains configuration for the "cookie" hash policy type.
 // This is specified to have Envoy generate a cookie for a client on its first request.
 type CookieConfig struct {
-	// TTL for generated cookies
+	// Generates a session cookie with no expiration.
+	Session bool `json:",omitempty"`
+
+	// TTL for generated cookies. Cannot be specified for session cookies.
 	TTL time.Duration `json:",omitempty"`
 
 	// The path to set for the cookie

api/config_entry_discoverychain_test.go

@@ -326,6 +326,14 @@ func TestAPI_ConfigEntry_ServiceResolver_LoadBalancer(t *testing.T) {
 								TTL:  20 * time.Millisecond,
 							},
 						},
+						{
+							Field:      "cookie",
+							FieldValue: "sugar",
+							CookieConfig: &CookieConfig{
+								Session: true,
+								Path:    "/tin",
+							},
+						},
 						{
 							SourceIP: true,
 						},

api/config_entry_test.go

@@ -613,6 +613,112 @@ func TestDecodeConfigEntry(t *testing.T) {
 				Name: "main",
 			},
 		},
+		{
+			name: "service-resolver: envoy hash lb kitchen sink",
+			body: `
+			{
+				"Kind": "service-resolver",
+				"Name": "main",
+				"LoadBalancer": {
+					"Policy": "ring_hash",
+					"RingHashConfig": {
+						"MinimumRingSize": 1,
+						"MaximumRingSize": 2
+					},
+					"HashPolicies": [
+						{
+							"Field": "cookie",
+							"FieldValue": "good-cookie",
+							"CookieConfig": {
+								"TTL": "1s",
+								"Path": "/oven"
+							},
+							"Terminal": true
+						},
+						{
+							"Field": "cookie",
+							"FieldValue": "less-good-cookie",
+							"CookieConfig": {
+								"Session": true,
+								"Path": "/toaster"
+							},
+							"Terminal": true
+						},
+						{
+							"Field": "header",
+							"FieldValue": "x-user-id"
+						},
+						{
+							"SourceIP": true
+						}
+					]
+				}
+			}
+			`,
+			expect: &ServiceResolverConfigEntry{
+				Kind: "service-resolver",
+				Name: "main",
+				LoadBalancer: &LoadBalancer{
+					Policy: "ring_hash",
+					RingHashConfig: &RingHashConfig{
+						MinimumRingSize: 1,
+						MaximumRingSize: 2,
+					},
+					HashPolicies: []HashPolicy{
+						{
+							Field:      "cookie",
+							FieldValue: "good-cookie",
+							CookieConfig: &CookieConfig{
+								TTL:  1 * time.Second,
+								Path: "/oven",
+							},
+							Terminal: true,
+						},
+						{
+							Field:      "cookie",
+							FieldValue: "less-good-cookie",
+							CookieConfig: &CookieConfig{
+								Session: true,
+								Path:    "/toaster",
+							},
+							Terminal: true,
+						},
+						{
+							Field:      "header",
+							FieldValue: "x-user-id",
+						},
+						{
+							SourceIP: true,
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "service-resolver: envoy least request kitchen sink",
+			body: `
+			{
+				"Kind": "service-resolver",
+				"Name": "main",
+				"LoadBalancer": {
+					"Policy": "least_request",
+					"LeastRequestConfig": {
+						"ChoiceCount": 2
+					}
+				}
+			}
+			`,
+			expect: &ServiceResolverConfigEntry{
+				Kind: "service-resolver",
+				Name: "main",
+				LoadBalancer: &LoadBalancer{
+					Policy: "least_request",
+					LeastRequestConfig: &LeastRequestConfig{
+						ChoiceCount: 2,
+					},
+				},
+			},
+		},
 		{
 			name: "ingress-gateway",
 			body: `

command/config/write/config_write_test.go

@@ -1187,6 +1187,15 @@ func TestParseConfigEntry(t *testing.T) {
 							}
 							terminal = true
 						},
+						{
+							field = "cookie"
+							field_value = "less-good-cookie"
+							cookie_config = {
+								session = true
+								path = "/toaster"
+							}
+							terminal = true
+						},
 						{
 							field = "header"
 							field_value = "x-user-id"
@@ -1216,6 +1225,15 @@ func TestParseConfigEntry(t *testing.T) {
 							}
 							Terminal = true
 						},
+						{
+							Field = "cookie"
+							FieldValue = "less-good-cookie"
+							CookieConfig = {
+								Session = true
+								Path = "/toaster"
+							}
+							Terminal = true
+						},
 						{
 							Field = "header"
 							FieldValue = "x-user-id"
@@ -1246,6 +1264,15 @@ func TestParseConfigEntry(t *testing.T) {
 							},
 							"terminal": true
 						},
+						{
+							"field": "cookie",
+							"field_value": "less-good-cookie",
+							"cookie_config": {
+								"session": true,
+								"path": "/toaster"
+							},
+							"terminal": true
+						},
 						{
 							"field": "header",
 							"field_value": "x-user-id"
@@ -1277,6 +1304,15 @@ func TestParseConfigEntry(t *testing.T) {
 							},
 							"Terminal": true
 						},
+						{
+							"Field": "cookie",
+							"FieldValue": "less-good-cookie",
+							"CookieConfig": {
+								"Session": true,
+								"Path": "/toaster"
+							},
+							"Terminal": true
+						},
 						{
 							"Field": "header",
 							"FieldValue": "x-user-id"
@@ -1307,6 +1343,15 @@ func TestParseConfigEntry(t *testing.T) {
 							},
 							Terminal: true,
 						},
+						{
+							Field:      structs.HashPolicyCookie,
+							FieldValue: "less-good-cookie",
+							CookieConfig: &api.CookieConfig{
+								Session: true,
+								Path:    "/toaster",
+							},
+							Terminal: true,
+						},
 						{
 							Field:      structs.HashPolicyHeader,
 							FieldValue: "x-user-id",

website/pages/docs/agent/config-entries/service-resolver.mdx

@@ -206,7 +206,9 @@ LoadBalancer = {
      - `CookieConfig` `(CookieConfig)` - Additional configuration for the "cookie" hash policy type.
         This is specified to have Envoy generate a cookie for a client on its first request.
         
-       - `TTL` `(duration: 0s)` - TTL for generated cookies.
+       - `Session` `(bool: false)` - Generates a session cookie with no expiration.
+
+       - `TTL` `(duration: 0s)` - TTL for generated cookies. Cannot be specified for session cookies.
          
        - `Path` `(string: "")` - The path to set for the cookie.