Added hook parser and opaque in request

remote/gitlab/client/gitlab.go

@@ -74,6 +74,10 @@ func (c *Client) Do(method, url, opaque string, body []byte) ([]byte, error) {
 
 	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", c.Token))
 
+	if len(opaque) > 0 {
+		req.URL.Opaque = opaque
+	}
+
 	resp, err := c.Client.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("Client.Do error: %q", err)

remote/gitlab/client/hook.go

@@ -1,5 +1,41 @@
 package client
 
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// ParseHook parses hook payload from GitLab
 func ParseHook(payload []byte) (*HookPayload, error) {
-	return nil, nil
+	hp := HookPayload{}
+	if err := json.Unmarshal(payload, &hp); err != nil {
+		return nil, err
+	}
+
+	// Basic sanity check
+	switch {
+	case len(hp.ObjectKind) == 0:
+		// Assume this is a post-receive within repository
+		if len(hp.After) == 0 {
+			return nil, fmt.Errorf("Invalid hook received, commit hash not found.")
+		}
+	case hp.ObjectKind == "push":
+		if hp.Repository == nil {
+			return nil, fmt.Errorf("Invalid push hook received, attributes not found")
+		}
+	case hp.ObjectKind == "tag_push":
+		if hp.Repository == nil {
+			return nil, fmt.Errorf("Invalid tag push hook received, attributes not found")
+		}
+	case hp.ObjectKind == "issue":
+		fallthrough
+	case hp.ObjectKind == "merge_request":
+		if hp.ObjectAttributes == nil {
+			return nil, fmt.Errorf("Invalid hook received, attributes not found.")
+		}
+	default:
+		return nil, fmt.Errorf("Invalid hook received, payload format not recognized.")
+	}
+
+	return &hp, nil
 }