Coverage for mcpgateway / plugins / observability_adapter.py: 100%

1# -*- coding: utf-8 -*- 

2"""Location: ./mcpgateway/plugins/observability_adapter.py 

3Copyright 2026 

4SPDX-License-Identifier: Apache-2.0 

5Authors: Fred Araujo 

6 

7Adapter bridging ObservabilityService to the plugin framework's 

8ObservabilityProvider protocol. 

9 

10The plugin framework defines a protocol-based ObservabilityProvider 

11interface so that it stays decoupled from gateway internals. This 

12adapter lives on the gateway side, wrapping ObservabilityService 

13with its own database sessions so the executor can call 

14start_span/end_span without needing a db parameter. 

15""" 

16 

17# Standard 

18import logging 

19from typing import Any, Dict, Optional 

20 

21# Third-Party 

22from sqlalchemy.orm import Session 

23 

24# First-Party 

25from mcpgateway.db import SessionLocal 

26from mcpgateway.services.observability_service import ObservabilityService 

27 

28logger = logging.getLogger(__name__) 

29 

30 

31class ObservabilityServiceAdapter: 

32 """Bridges ObservabilityService to the ObservabilityProvider protocol. 

33 

34 Satisfies the ObservabilityProvider protocol via duck typing (no explicit 

35 inheritance needed). Each call creates its own short-lived DB session, 

36 matching the pattern used in observability_middleware.py. 

37 """ 

38 

39 def __init__(self, service: Optional[ObservabilityService] = None): 

40 """Initialize the adapter. 

41 

42 Args: 

43 service: ObservabilityService instance to wrap (creates one if not provided). 

44 """ 

45 self._service = service or ObservabilityService() 

46 

47 def _make_session(self) -> Session: 

48 """Create a fresh DB session for observability writes. 

49 

50 Returns: 

51 A new SQLAlchemy session. 

52 """ 

53 return SessionLocal() 

54 

55 def start_span( 

56 self, 

57 trace_id: str, 

58 name: str, 

59 kind: str = "internal", 

60 resource_type: Optional[str] = None, 

61 resource_name: Optional[str] = None, 

62 attributes: Optional[Dict[str, Any]] = None, 

63 ) -> Optional[str]: 

64 """Start a span by delegating to ObservabilityService with a fresh DB session. 

65 

66 Args: 

67 trace_id: The trace identifier. 

68 name: The span name. 

69 kind: The span kind (e.g. "internal", "client", "server"). 

70 resource_type: Optional resource type being traced. 

71 resource_name: Optional resource name being traced. 

72 attributes: Optional key-value attributes for the span. 

73 

74 Returns: 

75 The span identifier, or None on failure. 

76 """ 

77 db: Optional[Session] = None 

78 try: 

79 db = self._make_session() 

80 return self._service.start_span( 

81 db=db, 

82 trace_id=trace_id, 

83 name=name, 

84 kind=kind, 

85 resource_type=resource_type, 

86 resource_name=resource_name, 

87 attributes=attributes, 

88 ) 

89 except Exception as exc: 

90 logger.warning("ObservabilityServiceAdapter.start_span failed: %s", exc) 

91 if db: 

92 try: 

93 db.rollback() 

94 except Exception: # nosec B110 

95 pass 

96 return None 

97 finally: 

98 if db: 

99 try: 

100 db.close() 

101 except Exception: # nosec B110 

102 pass 

103 

104 def end_span( 

105 self, 

106 span_id: Optional[str], 

107 status: str = "ok", 

108 attributes: Optional[Dict[str, Any]] = None, 

109 ) -> None: 

110 """End a span by delegating to ObservabilityService with a fresh DB session. 

111 

112 Args: 

113 span_id: The span identifier returned by start_span. 

114 status: The span status (e.g. "ok", "error"). 

115 attributes: Optional additional attributes to attach. 

116 """ 

117 if span_id is None: 

118 return 

119 db: Optional[Session] = None 

120 try: 

121 db = self._make_session() 

122 self._service.end_span( 

123 db=db, 

124 span_id=span_id, 

125 status=status, 

126 attributes=attributes, 

127 ) 

128 except Exception as exc: 

129 logger.warning("ObservabilityServiceAdapter.end_span failed: %s", exc) 

130 if db: 

131 try: 

132 db.rollback() 

133 except Exception: # nosec B110 

134 pass 

135 finally: 

136 if db: 

137 try: 

138 db.close() 

139 except Exception: # nosec B110 

140 pass