[Webhook] Expose User-Agent and X-{NAME} via Config, enhance request headers (#289)

internal/services/webhook/service.go

@@ -25,6 +25,14 @@ const (
 )
 
 type Config struct {
+	// UserAgentIdentity specifies the identity used for the user agent header
+	// IMPORTANT: do not include version.
+	UserAgentIdentity string `envconfig:"GITNESS_WEBHOOK_USER_AGENT_IDENTITY" default:"Gitness"`
+	// HeaderIdentity specifies the identity used for headers in webhook calls (e.g. X-Gitness-Trigger, ...).
+	// NOTE: If no value is provided, the UserAgentIdentity will be used.
+	HeaderIdentity string `envconfig:"GITNESS_WEBHOOK_HEADER_IDENTITY"`
+	// EventReaderName is the name used to read events from stream.
+	// Note: this should be different for every running instance.
 	EventReaderName     string `envconfig:"GITNESS_WEBHOOK_EVENT_READER_NAME"`
 	Concurrency         int    `envconfig:"GITNESS_WEBHOOK_CONCURRENCY" default:"4"`
 	MaxRetries          int    `envconfig:"GITNESS_WEBHOOK_MAX_RETRIES" default:"3"`
@@ -32,13 +40,16 @@ type Config struct {
 	AllowLoopback       bool   `envconfig:"GITNESS_WEBHOOK_ALLOW_LOOPBACK" default:"false"`
 }
 
-func (c *Config) Validate() error {
+func (c *Config) Prepare() error {
 	if c == nil {
 		return errors.New("config is required")
 	}
 	if c.EventReaderName == "" {
 		return errors.New("config.EventReaderName is required")
 	}
+	if c.UserAgentIdentity == "" {
+		return errors.New("config.UserAgentIdentity is required")
+	}
 	if c.Concurrency < 1 {
 		return errors.New("config.Concurrency has to be a positive number")
 	}
@@ -46,6 +57,11 @@ func (c *Config) Validate() error {
 		return errors.New("config.MaxRetries can't be negative")
 	}
 
+	// Backfill data
+	if c.HeaderIdentity == "" {
+		c.HeaderIdentity = c.UserAgentIdentity
+	}
+
 	return nil
 }
 
@@ -61,6 +77,8 @@ type Service struct {
 
 	secureHTTPClient   *http.Client
 	insecureHTTPClient *http.Client
+
+	config Config
 }
 
 func NewService(ctx context.Context, config Config,
@@ -69,7 +87,7 @@ func NewService(ctx context.Context, config Config,
 	webhookStore store.WebhookStore, webhookExecutionStore store.WebhookExecutionStore,
 	repoStore store.RepoStore, pullreqStore store.PullReqStore, urlProvider *url.Provider,
 	principalStore store.PrincipalStore, gitRPCClient gitrpc.Interface) (*Service, error) {
-	if err := config.Validate(); err != nil {
+	if err := config.Prepare(); err != nil {
 		return nil, fmt.Errorf("provided config is invalid: %w", err)
 	}
 	service := &Service{
@@ -83,6 +101,8 @@ func NewService(ctx context.Context, config Config,
 
 		secureHTTPClient:   newHTTPClient(config.AllowLoopback, config.AllowPrivateNetwork, false),
 		insecureHTTPClient: newHTTPClient(config.AllowLoopback, config.AllowPrivateNetwork, true),
+
+		config: config,
 	}
 
 	_, err := gitReaderFactory.Launch(ctx, eventsReaderGroupName, config.EventReaderName,

internal/services/webhook/trigger.go

@@ -212,7 +212,7 @@ func (s *Service) executeWebhook(ctx context.Context, webhook *types.Webhook, tr
 	defer cancel()
 
 	// create request from webhook and body
-	req, err := prepareHTTPRequest(ctx, &execution, webhook, body)
+	req, err := s.prepareHTTPRequest(ctx, &execution, triggerType, webhook, body)
 	if err != nil {
 		return &execution, err
 	}
@@ -266,10 +266,10 @@ func (s *Service) executeWebhook(ctx context.Context, webhook *types.Webhook, tr
 }
 
 // prepareHTTPRequest prepares a new http.Request object for the webhook using the provided body as request body.
-// All execution.Request.XXX values are set accordingly
+// All execution.Request.XXX values are set accordingly.
 // NOTE: if the body is an io.Reader, the value is used as response body as is, otherwise it'll be JSON serialized.
-func prepareHTTPRequest(ctx context.Context, execution *types.WebhookExecution,
+func (s *Service) prepareHTTPRequest(ctx context.Context, execution *types.WebhookExecution,
-	webhook *types.Webhook, body any) (*http.Request, error) {
+	triggerType enum.WebhookTrigger, webhook *types.Webhook, body any) (*http.Request, error) {
 	// set URL as is (already has been validated, any other error will be caught in request creation)
 	execution.Request.URL = webhook.URL
 
@@ -318,8 +318,12 @@ func prepareHTTPRequest(ctx context.Context, execution *types.WebhookExecution,
 	}
 
 	// setup headers
-	req.Header.Add("User-Agent", fmt.Sprintf("Gitness/%s", version.Version))
+	req.Header.Add("User-Agent", fmt.Sprintf("%s/%s", s.config.UserAgentIdentity, version.Version))
 	req.Header.Add("Content-Type", "application/json")
+	req.Header.Add(s.toXHeader("Trigger"), string(triggerType))
+	req.Header.Add(s.toXHeader("Webhook-Id"), fmt.Sprint(webhook.ID))
+	req.Header.Add(s.toXHeader("Webhook-Parent-Type"), string(webhook.ParentType))
+	req.Header.Add(s.toXHeader("Webhook-Parent-Id"), fmt.Sprint(webhook.ParentID))
 
 	// add HMAC only if a secret was provided
 	if webhook.Secret != "" {
@@ -328,8 +332,7 @@ func prepareHTTPRequest(ctx context.Context, execution *types.WebhookExecution,
 		if err != nil {
 			return nil, fmt.Errorf("failed to generate SHA256 based HMAC: %w", err)
 		}
-		// TODO: Take 'Gitness' as config input?
+		req.Header.Add(s.toXHeader("Signature"), hmac)
-		req.Header.Add("X-Gitness-Signature", hmac)
 	}
 
 	hBuffer := &bytes.Buffer{}
@@ -345,6 +348,10 @@ func prepareHTTPRequest(ctx context.Context, execution *types.WebhookExecution,
 	return req, nil
 }
 
+func (s *Service) toXHeader(name string) string {
+	return fmt.Sprintf("X-%s-%s", s.config.HeaderIdentity, name)
+}
+
 //nolint:funlen // refactor if needed
 func handleWebhookResponse(execution *types.WebhookExecution, resp *http.Response) error {
 	// store status (handle status later - want to first read body)