feat: add support for X-Request-Id header in responses and logs

go.mod

@@ -21,12 +21,7 @@ require (
 	golang.org/x/sync v0.12.0
 	gopkg.in/yaml.v3 v3.0.1
 	k8s.io/klog/v2 v2.130.1
-)
-
-require (
-	github.com/dgraph-io/ristretto/v2 v2.3.0 // indirect
-	github.com/dustin/go-humanize v1.0.1 // indirect
-	go.uber.org/multierr v1.11.0 // indirect
+	sigs.k8s.io/controller-runtime v0.21.0
 )
 
 require (
@@ -35,7 +30,9 @@ require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/daulet/tokenizers v1.22.1 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/dgraph-io/ristretto/v2 v2.3.0 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/emicklei/go-restful/v3 v3.11.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.7.0 // indirect
 	github.com/go-openapi/jsonpointer v0.21.0 // indirect
@@ -68,6 +65,7 @@ require (
 	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	go.uber.org/automaxprocs v1.6.0 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/net v0.38.0 // indirect
 	golang.org/x/oauth2 v0.27.0 // indirect
 	golang.org/x/sys v0.35.0 // indirect
@@ -83,7 +81,6 @@ require (
 	k8s.io/client-go v0.33.0 // indirect
 	k8s.io/kube-openapi v0.0.0-20250318190949-c8a335a9a2ff // indirect
 	k8s.io/utils v0.0.0-20241104100929-3ea5e8cea738 // indirect
-	sigs.k8s.io/controller-runtime v0.21.0
 	sigs.k8s.io/json v0.0.0-20241010143419-9aa6b5e7a4b3 // indirect
 	sigs.k8s.io/randfill v1.0.0 // indirect
 	sigs.k8s.io/structured-merge-diff/v4 v4.6.0 // indirect

pkg/common/config.go

@@ -223,6 +223,9 @@ type Configuration struct {
 
 	// EnableSleepMode enables sleep mode
 	EnableSleepMode bool `yaml:"enable-sleep-mode" json:"enable-sleep-mode"`
+
+	// EnableRequestIDHeaders enables including X-Request-Id header in responses
+	EnableRequestIDHeaders bool `yaml:"enable-request-id-headers" json:"enable-request-id-headers"`
 }
 
 type Metrics struct {
@@ -749,6 +752,7 @@ func ParseCommandParamsAndLoadConfig() (*Configuration, error) {
 	f.BoolVar(&config.DatasetInMemory, "dataset-in-memory", config.DatasetInMemory, "Load the entire dataset into memory for faster access")
 
 	f.BoolVar(&config.EnableSleepMode, "enable-sleep-mode", config.EnableSleepMode, "Enable sleep mode")
+	f.BoolVar(&config.EnableRequestIDHeaders, "enable-request-id-headers", config.EnableRequestIDHeaders, "Enable including X-Request-Id header in responses")
 
 	f.IntVar(&config.FailureInjectionRate, "failure-injection-rate", config.FailureInjectionRate, "Probability (0-100) of injecting failures")
 	failureTypes := getParamValueFromArgs("failure-types")

pkg/llm-d-inference-sim/server.go

@@ -109,9 +109,20 @@ func (s *VllmSimulator) startServer(ctx context.Context, listener net.Listener)
 	}
 }
 
+// getRequestID retrieves the request ID from the X-Request-Id header or generates a new one if not present
+func (s *VllmSimulator) getRequestID(ctx *fasthttp.RequestCtx) string {
+	if s.config.EnableRequestIDHeaders {
+		requestID := string(ctx.Request.Header.Peek(requestIDHeader))
+		if requestID != "" {
+			return requestID
+		}
+	}
+	return s.random.GenerateUUIDString()
+}
+
 // readRequest reads and parses data from the body of the given request according the type defined by isChatCompletion
 func (s *VllmSimulator) readRequest(ctx *fasthttp.RequestCtx, isChatCompletion bool) (openaiserverapi.CompletionRequest, error) {
-	requestID := s.random.GenerateUUIDString()
+	requestID := s.getRequestID(ctx)
 
 	if isChatCompletion {
 		var req openaiserverapi.ChatCompletionRequest
@@ -266,6 +277,11 @@ func (s *VllmSimulator) sendCompletionResponse(ctx *fasthttp.RequestCtx, resp op
 	if s.namespace != "" {
 		ctx.Response.Header.Add(namespaceHeader, s.namespace)
 	}
+	if s.config.EnableRequestIDHeaders {
+		if requestID := resp.GetRequestID(); requestID != "" {
+			ctx.Response.Header.Add(requestIDHeader, requestID)
+		}
+	}
 	ctx.Response.SetBody(data)
 }
 

pkg/llm-d-inference-sim/server_test.go

@@ -25,11 +25,13 @@ import (
 	"strings"
 	"time"
 
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"github.com/valyala/fasthttp"
+
 	"github.com/llm-d/llm-d-inference-sim/pkg/common"
 	kvcache "github.com/llm-d/llm-d-inference-sim/pkg/kv-cache"
 	vllmapi "github.com/llm-d/llm-d-inference-sim/pkg/vllm-api"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
 )
 
 const tmpDir = "./tests-tmp/"
@@ -212,6 +214,111 @@ var _ = Describe("Server", func() {
 
 	})
 
+	Context("request ID headers", func() {
+		testRequestIDHeader := func(enableRequestID bool, endpoint, reqBody, inputRequestID string, expectRequestID *string, validateBody func([]byte)) {
+			ctx := context.TODO()
+			args := []string{"cmd", "--model", testModel, "--mode", common.ModeEcho}
+			if enableRequestID {
+				args = append(args, "--enable-request-id-headers")
+			}
+			client, err := startServerWithArgs(ctx, args)
+			Expect(err).NotTo(HaveOccurred())
+
+			req, err := http.NewRequest("POST", "http://localhost"+endpoint, strings.NewReader(reqBody))
+			Expect(err).NotTo(HaveOccurred())
+			req.Header.Set(fasthttp.HeaderContentType, "application/json")
+			if inputRequestID != "" {
+				req.Header.Set(requestIDHeader, inputRequestID)
+			}
+
+			resp, err := client.Do(req)
+			Expect(err).NotTo(HaveOccurred())
+			defer func() {
+				err := resp.Body.Close()
+				Expect(err).NotTo(HaveOccurred())
+			}()
+
+			Expect(resp.StatusCode).To(Equal(http.StatusOK))
+
+			if expectRequestID != nil {
+				actualRequestID := resp.Header.Get(requestIDHeader)
+				if *expectRequestID != "" {
+					// When a request ID is provided, it should be echoed back
+					Expect(actualRequestID).To(Equal(*expectRequestID))
+				} else {
+					// When no request ID is provided, a UUID should be generated
+					Expect(actualRequestID).NotTo(BeEmpty())
+					Expect(len(actualRequestID)).To(BeNumerically(">", 30))
+				}
+			} else {
+				// When request ID headers are disabled, the header should be empty
+				Expect(resp.Header.Get(requestIDHeader)).To(BeEmpty())
+			}
+
+			if validateBody != nil {
+				body, err := io.ReadAll(resp.Body)
+				Expect(err).NotTo(HaveOccurred())
+				validateBody(body)
+			}
+		}
+
+		DescribeTable("request ID behavior",
+			testRequestIDHeader,
+			Entry("includes X-Request-Id when enabled",
+				true,
+				"/v1/chat/completions",
+				`{"messages": [{"role": "user", "content": "Hello"}], "model": "`+testModel+`", "max_tokens": 5}`,
+				"test-request-id-123",
+				ptr("test-request-id-123"),
+				nil,
+			),
+			Entry("excludes X-Request-Id when disabled",
+				false,
+				"/v1/chat/completions",
+				`{"messages": [{"role": "user", "content": "Hello"}], "model": "`+testModel+`", "max_tokens": 5}`,
+				"test-request-id-456",
+				nil,
+				nil,
+			),
+			Entry("includes X-Request-Id in streaming response",
+				true,
+				"/v1/chat/completions",
+				`{"messages": [{"role": "user", "content": "Hello"}], "model": "`+testModel+`", "max_tokens": 5, "stream": true}`,
+				"test-streaming-789",
+				ptr("test-streaming-789"),
+				nil,
+			),
+			Entry("works with text completions endpoint",
+				true,
+				"/v1/completions",
+				`{"prompt": "Hello world", "model": "`+testModel+`", "max_tokens": 5}`,
+				"text-request-111",
+				ptr("text-request-111"),
+				nil,
+			),
+			Entry("generates UUID when no request ID provided",
+				true,
+				"/v1/chat/completions",
+				`{"messages": [{"role": "user", "content": "Hello"}], "model": "`+testModel+`", "max_tokens": 5}`,
+				"",
+				ptr(""),
+				nil,
+			),
+			Entry("uses request ID in response body ID field",
+				true,
+				"/v1/chat/completions",
+				`{"messages": [{"role": "user", "content": "Hello"}], "model": "`+testModel+`", "max_tokens": 5}`,
+				"body-test-999",
+				ptr("body-test-999"),
+				func(body []byte) {
+					var resp map[string]any
+					Expect(json.Unmarshal(body, &resp)).To(Succeed())
+					Expect(resp["id"]).To(Equal("chatcmpl-body-test-999"))
+				},
+			),
+		)
+	})
+
 	Context("sleep mode", Ordered, func() {
 		AfterAll(func() {
 			err := os.RemoveAll(tmpDir)

pkg/llm-d-inference-sim/simulator.go

@@ -51,6 +51,7 @@ const (
 	podHeader       = "x-inference-pod"
 	portHeader      = "x-inference-port"
 	namespaceHeader = "x-inference-namespace"
+	requestIDHeader = "X-Request-Id"
 	podNameEnv      = "POD_NAME"
 	podNsEnv        = "POD_NAMESPACE"
 )
@@ -581,9 +582,9 @@ func (s *VllmSimulator) responseSentCallback(model string, isChatCompletion bool
 // modelName - display name returned to the client and used in metrics. It is either the first alias
 // from --served-model-name (for a base-model request) or the LoRA adapter name (for a LoRA request).
 func (s *VllmSimulator) createCompletionResponse(logprobs *int, isChatCompletion bool, respTokens []string, toolCalls []openaiserverapi.ToolCall,
-	finishReason *string, usageData *openaiserverapi.Usage, modelName string, doRemoteDecode bool) openaiserverapi.CompletionResponse {
-	baseResp := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+s.random.GenerateUUIDString(),
-		time.Now().Unix(), modelName, usageData)
+	finishReason *string, usageData *openaiserverapi.Usage, modelName string, doRemoteDecode bool, requestID string) openaiserverapi.CompletionResponse {
+	baseResp := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+requestID,
+		time.Now().Unix(), modelName, usageData, requestID)
 
 	if doRemoteDecode {
 		baseResp.KVParams = &openaiserverapi.KVTransferParams{}
@@ -663,9 +664,10 @@ func (s *VllmSimulator) sendResponse(reqCtx *openaiserverapi.CompletionReqCtx, r
 	if toolCalls == nil {
 		logprobs = reqCtx.CompletionReq.GetLogprobs()
 	}
+	requestID := reqCtx.CompletionReq.GetRequestID()
 
 	resp := s.createCompletionResponse(logprobs, reqCtx.IsChatCompletion, respTokens, toolCalls, &finishReason, usageData, modelName,
-		reqCtx.CompletionReq.IsDoRemoteDecode())
+		reqCtx.CompletionReq.IsDoRemoteDecode(), requestID)
 
 	// calculate how long to wait before returning the response, time is based on number of tokens
 	nCachedPromptTokens := reqCtx.CompletionReq.GetNumberOfCachedPromptTokens()

pkg/llm-d-inference-sim/streaming.go

@@ -60,6 +60,9 @@ func (s *VllmSimulator) sendStreamingResponse(context *streamingContext, respons
 	if s.namespace != "" {
 		context.ctx.Response.Header.Add(namespaceHeader, s.namespace)
 	}
+	if s.config.EnableRequestIDHeaders {
+		context.ctx.Response.Header.Add(requestIDHeader, context.requestID)
+	}
 
 	context.ctx.SetBodyStreamWriter(func(w *bufio.Writer) {
 		context.creationTime = time.Now().Unix()
@@ -176,8 +179,8 @@ func (s *VllmSimulator) sendTokenChunks(context *streamingContext, w *bufio.Writ
 // createUsageChunk creates and returns a CompletionRespChunk with usage data, a single chunk of streamed completion API response,
 // supports both modes (text and chat)
 func (s *VllmSimulator) createUsageChunk(context *streamingContext, usageData *openaiserverapi.Usage) openaiserverapi.CompletionRespChunk {
-	baseChunk := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+s.random.GenerateUUIDString(),
-		context.creationTime, context.model, usageData)
+	baseChunk := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+context.requestID,
+		context.creationTime, context.model, usageData, context.requestID)
 
 	if context.isChatCompletion {
 		baseChunk.Object = chatCompletionChunkObject
@@ -191,8 +194,8 @@ func (s *VllmSimulator) createUsageChunk(context *streamingContext, usageData *o
 // createTextCompletionChunk creates and returns a CompletionRespChunk, a single chunk of streamed completion API response,
 // for text completion.
 func (s *VllmSimulator) createTextCompletionChunk(context *streamingContext, token string, finishReason *string) openaiserverapi.CompletionRespChunk {
-	baseChunk := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+s.random.GenerateUUIDString(),
-		context.creationTime, context.model, nil)
+	baseChunk := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+context.requestID,
+		context.creationTime, context.model, nil, context.requestID)
 	baseChunk.Object = textCompletionObject
 
 	choice := openaiserverapi.CreateTextRespChoice(openaiserverapi.CreateBaseResponseChoice(0, finishReason), token)
@@ -214,8 +217,8 @@ func (s *VllmSimulator) createTextCompletionChunk(context *streamingContext, tok
 // API response, for chat completion. It sets either role, or token, or tool call info in the message.
 func (s *VllmSimulator) createChatCompletionChunk(context *streamingContext, token string, tool *openaiserverapi.ToolCall,
 	role string, finishReason *string) openaiserverapi.CompletionRespChunk {
-	baseChunk := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+s.random.GenerateUUIDString(),
-		context.creationTime, context.model, nil)
+	baseChunk := openaiserverapi.CreateBaseCompletionResponse(chatComplIDPrefix+context.requestID,
+		context.creationTime, context.model, nil, context.requestID)
 	baseChunk.Object = chatCompletionChunkObject
 	chunk := openaiserverapi.CreateChatCompletionRespChunk(baseChunk,
 		[]openaiserverapi.ChatRespChunkChoice{

pkg/llm-d-inference-sim/test_utils.go

@@ -541,3 +541,7 @@ func checkSimSleeping(client *http.Client, expectedToSleep bool) {
 	expect := fmt.Sprintf("{\"is_sleeping\":%t}", expectedToSleep)
 	gomega.Expect(string(body)).To(gomega.Equal(expect))
 }
+
+func ptr[T any](v T) *T {
+	return &v
+}

pkg/openai-server-api/response.go

@@ -26,7 +26,9 @@ import (
 )
 
 // CompletionResponse interface representing both completion response types (text and chat)
-type CompletionResponse interface{}
+type CompletionResponse interface {
+	GetRequestID() string
+}
 
 // baseCompletionResponse contains base completion response related information
 type baseCompletionResponse struct {
@@ -42,6 +44,8 @@ type baseCompletionResponse struct {
 	Object string `json:"object"`
 	// KVParams kv transfer related fields
 	KVParams *KVTransferParams `json:"kv_transfer_params"`
+	// RequestID is the unique request ID for tracking
+	RequestID string `json:"-"`
 }
 
 // Usage contains token Usage statistics
@@ -303,8 +307,13 @@ func CreateTextRespChoice(base baseResponseChoice, text string) TextRespChoice {
 	return TextRespChoice{baseResponseChoice: base, Text: text, Logprobs: nil}
 }
 
-func CreateBaseCompletionResponse(id string, created int64, model string, usage *Usage) baseCompletionResponse {
-	return baseCompletionResponse{ID: id, Created: created, Model: model, Usage: usage}
+func CreateBaseCompletionResponse(id string, created int64, model string, usage *Usage, requestID string) baseCompletionResponse {
+	return baseCompletionResponse{ID: id, Created: created, Model: model, Usage: usage, RequestID: requestID}
+}
+
+// GetRequestID returns the request ID from the response
+func (b baseCompletionResponse) GetRequestID() string {
+	return b.RequestID
 }
 
 func CreateChatCompletionResponse(base baseCompletionResponse, choices []ChatRespChoice) *ChatCompletionResponse {