chore(gensupport): merge x-goog-api-client vals into a single header

internal/gensupport/send.go

@@ -48,8 +48,24 @@ func SendRequest(ctx context.Context, client *http.Client, req *http.Request) (*
  if ctx != nil {
  headers := callctx.HeadersFromContext(ctx)
  for k, vals := range headers {
- for _, v := range vals {
- req.Header.Add(k, v)
+ if k == "x-goog-api-client" {
+ // Merge all values into a single "x-goog-api-client" header.
+ var mergedVal strings.Builder
+ baseXGoogHeader := req.Header.Get("X-Goog-Api-Client")
+ if baseXGoogHeader != "" {
+ mergedVal.WriteString(baseXGoogHeader)
+ mergedVal.WriteRune(' ')
+ }
+ for _, v := range vals {
+ mergedVal.WriteString(v)
+ mergedVal.WriteRune(' ')
+ }
+ // Remove the last space and replace the header on the request.
+ req.Header.Set(k, mergedVal.String()[:mergedVal.Len()-1])
+ } else {
+ for _, v := range vals {
+ req.Header.Add(k, v)
+ }
  }
  }
  }
@@ -118,7 +134,9 @@ func sendAndRetry(ctx context.Context, client *http.Client, req *http.Request, r
  var err error
  attempts := 1
  invocationID := uuid.New().String()
- baseXGoogHeader := req.Header.Get("X-Goog-Api-Client")
+
+ xGoogHeaderVals := req.Header.Values("X-Goog-Api-Client")
+ baseXGoogHeader := strings.Join(xGoogHeaderVals, " ")
 
  // Loop to retry the request, up to the context deadline.
  var pause time.Duration

internal/gensupport/send_test.go

@@ -9,6 +9,7 @@ import (
  "errors"
  "fmt"
  "net/http"
+ "regexp"
  "testing"
 
  "github.com/google/go-cmp/cmp"
@@ -36,13 +37,24 @@ func TestSendRequestWithRetry(t *testing.T) {
 }
 
 type headerRoundTripper struct {
- wantHeader http.Header
+ wantHeader http.Header
+ wantXgoogAPIRegex string // test x-goog-api-client separately
 }
 
 func (rt *headerRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
+ // Test x-goog-api-client with a regex, since invocation ids are randomly generated
+ match, err := regexp.MatchString(rt.wantXgoogAPIRegex, r.Header.Get("X-Goog-Api-Client"))
+ if err != nil {
+ return nil, fmt.Errorf("compiling regexp: %v", err)
+ }
+ if !match {
+ return nil, fmt.Errorf("X-Goog-Api-Client header has wrong format\ngot %v\nwant regex matching %v", r.Header.Get("X-Goog-Api-Client"), rt.wantXgoogAPIRegex)
+ }
+
  // Ignore x-goog headers sent by SendRequestWithRetry
- r.Header.Del("X-Goog-Api-Client")
  r.Header.Del("X-Goog-Gcs-Idempotency-Token")
+ r.Header.Del("X-Goog-Api-Client") // this was tested above already
+
  if diff := cmp.Diff(r.Header, rt.wantHeader); diff != "" {
  return nil, fmt.Errorf("headers don't match: %v", diff)
  }
@@ -53,19 +65,48 @@ func (rt *headerRoundTripper) RoundTrip(r *http.Request) (*http.Response, error)
 func TestSendRequestHeader(t *testing.T) {
  ctx := context.Background()
  ctx = callctx.SetHeaders(ctx, "foo", "100", "bar", "200")
- client := http.Client{
- Transport: &headerRoundTripper{
- wantHeader: map[string][]string{"Foo": {"100"}, "Bar": {"200"}},
- },
+ transport := &headerRoundTripper{
+ wantHeader: map[string][]string{"Foo": {"100"}, "Bar": {"200"}},
  }
+ client := http.Client{Transport: transport}
+
  req, _ := http.NewRequest("GET", "url", nil)
  if _, err := SendRequest(ctx, &client, req); err != nil {
  t.Errorf("SendRequest: %v", err)
  }
+
+ // SendRequestWithRetry adds retry and idempotency headers
+ transport.wantXgoogAPIRegex = "^gccl-invocation-id/.{36} gccl-attempt-count/[0-9]+ $"
  req2, _ := http.NewRequest("GET", "url", nil)
  if _, err := SendRequestWithRetry(ctx, &client, req2, nil); err != nil {
+ t.Errorf("SendRequestWithRetry: %v", err)
+ }
+}
+
+// Ensure that x-goog-api-client headers set via the context are merged properly
+// and passed through to the request as expected.
+func TestSendRequestXgoogHeaderxxx(t *testing.T) {
+ ctx := context.Background()
+ ctx = callctx.SetHeaders(ctx, "x-goog-api-client", "val/1", "bar", "200", "x-goog-api-client", "val/2")
+ ctx = callctx.SetHeaders(ctx, "x-goog-api-client", "val/11 val/22")
+
+ transport := &headerRoundTripper{
+ wantHeader: map[string][]string{"Bar": {"200"}},
+ wantXgoogAPIRegex: "^val/1 val/2 val/11 val/22$",
+ }
+ client := http.Client{Transport: transport}
+
+ req, _ := http.NewRequest("GET", "url", nil)
+ if _, err := SendRequest(ctx, &client, req); err != nil {
  t.Errorf("SendRequest: %v", err)
  }
+
+ // SendRequestWithRetry adds retry and idempotency headers
+ transport.wantXgoogAPIRegex = fmt.Sprintf("^gccl-invocation-id/.{36} gccl-attempt-count/[0-9]+ %s$", transport.wantXgoogAPIRegex[1:len(transport.wantXgoogAPIRegex)-1])
+ req2, _ := http.NewRequest("GET", "url", nil)
+ if _, err := SendRequestWithRetry(ctx, &client, req2, nil); err != nil {
+ t.Errorf("SendRequestWithRetry: %v", err)
+ }
 }
 
 type brokenRoundTripper struct{}