fix: don't panic when datadog APM socket cannot be found, retry to wait for it to become available

cmd/gitdb/main.go

@@ -257,7 +257,7 @@ func setupJWT(cfg config, m *mux.Router, h *gitdb.CheckoutHandler, logger *log.L
 	if err != nil {
 		return fmt.Errorf("unable to parse public key in file %s: %w", cfg.JWTPublicKey, err)
 	}
-	keyFunc := func(token *jwt.Token) (interface{}, error) {
+	keyFunc := func(_ *jwt.Token) (interface{}, error) {
 		return parsedPublicKey, nil
 	}
 	h.SetupPublicJWTHandler(m, keyFunc, repoConfig.Repositories)
@@ -300,7 +300,7 @@ func setupJWTSigning(ctx context.Context, cfg config, log *log.Logger, m *mux.Ro
 		Auth: func(username string, password string) (bool, error) {
 			return username == cfg.JWTSignInUsername && password == cfg.JWTSignInPassword, nil
 		},
-		SigningString: func(username string) *rsa.PrivateKey {
+		SigningString: func(_ string) *rsa.PrivateKey {
 			return pKey
 		},
 	}

internal/gitdb/goget/git.go

@@ -290,7 +290,7 @@ func (g *GitCheckout) LsDir(ctx context.Context, dir string, branch string) (ret
 	if err != nil {
 		return nil, &unknownBranch{branch: branch, wraps: err}
 	}
-	retErr = g.tracing.StartSpanFromContext(ctx, tracing.SpanConfig{OperationName: "ls_dir"}, func(ctx context.Context) error {
+	retErr = g.tracing.StartSpanFromContext(ctx, tracing.SpanConfig{OperationName: "ls_dir"}, func(_ context.Context) error {
 		co, err := g.repo.CommitObject(r.Hash())
 		if err != nil {
 			return fmt.Errorf("unable to make commit object for hash %s: %w", r.Hash(), err)

internal/gitdb/tracing/datadog/datadog.go

@@ -63,14 +63,25 @@ func envToStruct(env []string, into interface{}) error {
 	return json.Unmarshal(b, into)
 }
 
+func verifyFileExistsWithRetry(file string, retries int, delay time.Duration) bool {
+	for i := 0; i < retries; i++ {
+		if fileExists(file) {
+			return true
+		}
+		time.Sleep(delay)
+	}
+	return false
+}
+
 func NewTracer(originalConfig tracing.Config) (tracing.Tracing, error) {
 	var cfg config
 	if err := envToStruct(originalConfig.Env, &cfg); err != nil {
 		return nil, fmt.Errorf("unable to convert env to config: %w", err)
 	}
-	if !fileExists(cfg.apmFile()) {
+	// the datadog APM socket is mounted from the host, sometimes it is not available immediately
+	if !verifyFileExistsWithRetry(cfg.apmFile(), 10, 1*time.Second) {
 		originalConfig.Log.Info(context.Background(), "Unable to find datadog APM file", zap.String("file_name", cfg.apmFile()))
-		return nil, nil
+		return nil, fmt.Errorf("unable to find datadog APM file: %s", cfg.apmFile())
 	}
 	u := &unixRoundTripper{
 		file:        cfg.apmFile(),

internal/httpserver/server_test.go

@@ -20,7 +20,7 @@ func TestJWTSignIn(t *testing.T) {
 		Auth: func(username string, password string) (bool, error) {
 			return username == "user" && password == "pass", nil
 		},
-		SigningString: func(username string) *rsa.PrivateKey {
+		SigningString: func(_ string) *rsa.PrivateKey {
 			return pk
 		},
 	}
@@ -31,7 +31,7 @@ func TestJWTSignIn(t *testing.T) {
 	j.ServeHTTP(rec, req)
 	require.Equal(t, http.StatusOK, rec.Code)
 
-	tok, err := jwt.Parse(rec.Body.String(), func(token *jwt.Token) (interface{}, error) {
+	tok, err := jwt.Parse(rec.Body.String(), func(_ *jwt.Token) (interface{}, error) {
 		return pk.Public(), nil
 	})
 	require.NoError(t, err)