refactor(BA-2753): Move error classes to its own module

Author: hhoikoo

src/ai/backend/agent/errors/__init__.py

@@ -0,0 +1,17 @@
+from ai.backend.common.exception import (
+    BackendAIError,
+    ErrorCode,
+    ErrorDetail,
+    ErrorDomain,
+    ErrorOperation,
+)
+
+
+class AgentIdNotFoundError(BackendAIError):
+    @classmethod
+    def error_code(cls) -> ErrorCode:
+        return ErrorCode(
+            domain=ErrorDomain.AGENT,
+            operation=ErrorOperation.ACCESS,
+            error_detail=ErrorDetail.NOT_FOUND,
+        )

src/ai/backend/agent/errors/runtime.py

@@ -5,35 +5,19 @@
 
 from ai.backend.agent.agent import AbstractAgent
 from ai.backend.agent.config.unified import AgentUnifiedConfig
+from ai.backend.agent.errors.runtime import AgentIdNotFoundError
 from ai.backend.agent.etcd import AgentEtcdClientView
 from ai.backend.agent.kernel import KernelRegistry
 from ai.backend.agent.monitor import AgentErrorPluginContext, AgentStatsPluginContext
 from ai.backend.agent.types import AgentBackend
 from ai.backend.common.auth import PublicKey
 from ai.backend.common.etcd import AsyncEtcd, ConfigScopes
-from ai.backend.common.exception import (
-    BackendAIError,
-    ErrorCode,
-    ErrorDetail,
-    ErrorDomain,
-    ErrorOperation,
-)
 from ai.backend.common.types import AgentId
 
 if TYPE_CHECKING:
     from .docker.metadata.server import MetadataServer
 
 
-class AgentIdNotFoundError(BackendAIError):
-    @classmethod
-    def error_code(cls) -> ErrorCode:
-        return ErrorCode(
-            domain=ErrorDomain.AGENT,
-            operation=ErrorOperation.ACCESS,
-            error_detail=ErrorDetail.NOT_FOUND,
-        )
-
-
 class AgentRuntime:
     _local_config: AgentUnifiedConfig
     _agents: dict[AgentId, AbstractAgent]