command: when generating envoy bootstrap configs use the datacenter returned from the agent services endpoint (#9229)

Fixes #9215

.changelog/9229.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+command: when generating envoy bootstrap configs use the datacenter returned from the agent services endpoint
+```

agent/agent_endpoint.go

@@ -170,7 +170,7 @@ func (s *HTTPHandlers) AgentReload(resp http.ResponseWriter, req *http.Request)
 	return nil, s.agent.ReloadConfig()
 }
 
-func buildAgentService(s *structs.NodeService) api.AgentService {
+func buildAgentService(s *structs.NodeService, dc string) api.AgentService {
 	weights := api.AgentWeights{Passing: 1, Warning: 1}
 	if s.Weights != nil {
 		if s.Weights.Passing > 0 {
@@ -200,6 +200,7 @@ func buildAgentService(s *structs.NodeService) api.AgentService {
 		CreateIndex:       s.CreateIndex,
 		ModifyIndex:       s.ModifyIndex,
 		Weights:           weights,
+		Datacenter:        dc,
 	}
 
 	if as.Tags == nil {
@@ -253,9 +254,11 @@ func (s *HTTPHandlers) AgentServices(resp http.ResponseWriter, req *http.Request
 	// anyway.
 	agentSvcs := make(map[string]*api.AgentService)
 
+	dc := s.agent.config.Datacenter
+
 	// Use empty list instead of nil
 	for id, s := range services {
-		agentService := buildAgentService(s)
+		agentService := buildAgentService(s, dc)
 		agentSvcs[id.ID] = &agentService
 	}
 
@@ -303,6 +306,8 @@ func (s *HTTPHandlers) AgentService(resp http.ResponseWriter, req *http.Request)
 
 	sid := structs.NewServiceID(id, &entMeta)
 
+	dc := s.agent.config.Datacenter
+
 	resultHash, service, err := s.agent.LocalBlockingQuery(false, hash, queryOpts.MaxQueryTime,
 		func(ws memdb.WatchSet) (string, interface{}, error) {
 
@@ -330,7 +335,7 @@ func (s *HTTPHandlers) AgentService(resp http.ResponseWriter, req *http.Request)
 			}
 
 			// Calculate the content hash over the response, minus the hash field
-			aSvc := buildAgentService(svc)
+			aSvc := buildAgentService(svc, dc)
 			reply := &aSvc
 
 			rawHash, err := hashstructure.Hash(reply, nil)
@@ -768,6 +773,8 @@ func (s *HTTPHandlers) AgentHealthServiceByID(resp http.ResponseWriter, req *htt
 
 	sid := structs.NewServiceID(serviceID, &entMeta)
 
+	dc := s.agent.config.Datacenter
+
 	if service := s.agent.State.Service(sid); service != nil {
 		if authz != nil && authz.ServiceRead(service.Service, &authzContext) != acl.Allow {
 			return nil, acl.ErrPermissionDenied
@@ -776,7 +783,7 @@ func (s *HTTPHandlers) AgentHealthServiceByID(resp http.ResponseWriter, req *htt
 		if returnTextPlain(req) {
 			return status, CodeWithPayloadError{StatusCode: code, Reason: status, ContentType: "text/plain"}
 		}
-		serviceInfo := buildAgentService(service)
+		serviceInfo := buildAgentService(service, dc)
 		result := &api.AgentServiceChecksInfo{
 			AggregatedStatus: status,
 			Checks:           healthChecks,
@@ -822,6 +829,8 @@ func (s *HTTPHandlers) AgentHealthServiceByName(resp http.ResponseWriter, req *h
 		return nil, acl.ErrPermissionDenied
 	}
 
+	dc := s.agent.config.Datacenter
+
 	code := http.StatusNotFound
 	status := fmt.Sprintf("ServiceName %s Not Found", serviceName)
 	services := s.agent.State.Services(&entMeta)
@@ -831,7 +840,7 @@ func (s *HTTPHandlers) AgentHealthServiceByName(resp http.ResponseWriter, req *h
 			sid := structs.NewServiceID(service.ID, &entMeta)
 
 			scode, sstatus, healthChecks := agentHealthService(sid, s)
-			serviceInfo := buildAgentService(service)
+			serviceInfo := buildAgentService(service, dc)
 			res := api.AgentServiceChecksInfo{
 				AggregatedStatus: sstatus,
 				Checks:           healthChecks,

agent/agent_endpoint_test.go

@@ -365,8 +365,9 @@ func TestAgent_Service(t *testing.T) {
 			Passing: 1,
 			Warning: 1,
 		},
-		Meta: map[string]string{},
-		Tags: []string{},
+		Meta:       map[string]string{},
+		Tags:       []string{},
+		Datacenter: "dc1",
 	}
 	fillAgentServiceEnterpriseMeta(expectedResponse, structs.DefaultEnterpriseMeta())
 
@@ -391,8 +392,9 @@ func TestAgent_Service(t *testing.T) {
 				Port:    1818,
 			},
 		},
-		Meta: map[string]string{},
-		Tags: []string{},
+		Meta:       map[string]string{},
+		Tags:       []string{},
+		Datacenter: "dc1",
 	}
 	fillAgentServiceEnterpriseMeta(expectWebResponse, structs.DefaultEnterpriseMeta())
 

api/agent.go

@@ -93,6 +93,8 @@ type AgentService struct {
 	// to include the Namespace in the hash. When we do, then we are in for lots of fun with tests.
 	// For now though, ignoring it works well enough.
 	Namespace string `json:",omitempty" bexpr:"-" hash:"ignore"`
+	// Datacenter is only ever returned and is ignored if presented.
+	Datacenter string `json:",omitempty" bexpr:"-" hash:"ignore"`
 }
 
 // AgentServiceChecksInfo returns information about a Service and its checks

api/agent_test.go

@@ -726,8 +726,9 @@ func TestAPI_AgentService(t *testing.T) {
 			Passing: 1,
 			Warning: 1,
 		},
-		Meta:      map[string]string{},
-		Namespace: defaultNamespace,
+		Meta:       map[string]string{},
+		Namespace:  defaultNamespace,
+		Datacenter: "dc1",
 	}
 	require.Equal(expect, got)
 	require.Equal(expect.ContentHash, qm.LastContentHash)

command/connect/envoy/envoy.go

@@ -478,6 +478,7 @@ func (c *cmd) templateArgs() (*BootstrapTplArgs, error) {
 		LocalAgentClusterName: xds.LocalAgentClusterName,
 		Namespace:             httpCfg.Namespace,
 		EnvoyVersion:          c.envoyVersion,
+		Datacenter:            httpCfg.Datacenter,
 	}, nil
 }
 
@@ -529,15 +530,11 @@ func (c *cmd) generateConfig() ([]byte, error) {
 		// cluster is using namespaces regardless.
 		args.Namespace = svc.Namespace
 	}
-	agent, err := c.client.Agent().Self()
-	if err != nil {
-		return nil, fmt.Errorf("failed to fetch agent config: %v", err)
+
+	if svc.Datacenter != "" {
+		// The agent will definitely have the definitive answer here.
+		args.Datacenter = svc.Datacenter
 	}
-	dc, ok := agent["Config"]["Datacenter"].(string)
-	if !ok {
-		return nil, fmt.Errorf("failed to fetch datacenter from agent. DC is: %T", agent["Config"]["Datacenter"])
-	}
-	args.Datacenter = dc
 
 	if !c.disableCentralConfig {
 		// Parse the bootstrap config

command/connect/envoy/envoy_test.go

@@ -991,9 +991,10 @@ func testMockAgentGatewayConfig(namespacesEnabled bool) http.HandlerFunc {
 
 		svc := map[string]*api.AgentService{
 			string(kind): {
-				Kind:    kind,
-				ID:      string(kind),
-				Service: string(kind),
+				Kind:       kind,
+				ID:         string(kind),
+				Service:    string(kind),
+				Datacenter: "dc1",
 			},
 		}
 
@@ -1036,6 +1037,7 @@ func testMockAgentProxyConfig(cfg map[string]interface{}, namespacesEnabled bool
 				DestinationServiceID:   serviceID,
 				Config:                 cfg,
 			},
+			Datacenter: "dc1",
 		}
 
 		if namespacesEnabled {

website/pages/api-docs/agent/service.mdx

@@ -74,6 +74,7 @@ $ curl \
     "Port": 8000,
     "Address": "",
     "EnableTagOverride": false,
+    "Datacenter": "dc1",
     "Weights": {
       "Passing": 10,
       "Warning": 1
@@ -185,6 +186,7 @@ $ curl \
     "Warning": 1
   },
   "EnableTagOverride": false,
+  "Datacenter": "dc1",
   "ContentHash": "4ecd29c7bc647ca8",
   "Proxy": {
     "DestinationServiceName": "web",
@@ -304,6 +306,7 @@ curl localhost:8500/v1/agent/health/service/name/web
       "Meta": null,
       "Port": 80,
       "EnableTagOverride": false,
+      "Datacenter": "dc1",
       "Connect": {
         "Native": false,
         "Proxy": null
@@ -331,6 +334,7 @@ curl localhost:8500/v1/agent/health/service/name/web
       "Meta": null,
       "Port": 80,
       "EnableTagOverride": false,
+      "Datacenter": "dc1",
       "Connect": {
         "Native": false,
         "Proxy": null
@@ -380,6 +384,7 @@ curl localhost:8500/v1/agent/health/service/id/web2
     "Meta": null,
     "Port": 80,
     "EnableTagOverride": false,
+    "Datacenter": "dc1",
     "Connect": {
       "Native": false,
       "Proxy": null
@@ -425,6 +430,7 @@ curl localhost:8500/v1/agent/health/service/id/web1
     "Meta": null,
     "Port": 80,
     "EnableTagOverride": false,
+    "Datacenter": "dc1",
     "Connect": {
       "Native": false,
       "Proxy": null