Better ISPyB logic (#511)

* refactor: Minor log tweak

* fix: Introduces 'ping_configured_connector'

---------

Co-authored-by: Alan Christie <[email protected]>

api/remote_ispyb_connector.py

@@ -12,6 +12,8 @@
     ISPyBRetrieveFailed,
 )
 
+logger: logging.Logger = logging.getLogger(__name__)
+
 
 class SSHConnector(Connector):
     def __init__(
@@ -34,6 +36,7 @@ def __init__(
 
         self.conn_inactivity = conn_inactivity
         self.lock = threading.Lock()
+        self.conn = None
         self.server = None
         self.last_activity_ts = None
 
@@ -49,6 +52,12 @@ def __init__(
                 'db_name': db,
             }
             self.remote_connect(**creds)
+            logger.debug(
+                "Started host=%s username=%s local_bind_port=%s",
+                ssh_host,
+                ssh_user,
+                self.server.local_bind_port,
+            )
 
         else:
             self.connect(
@@ -59,6 +68,7 @@ def __init__(
                 port=port,
                 conn_inactivity=conn_inactivity,
             )
+            logger.debug("Started host=%s user=%s port=%s", host, user, port)
 
     def remote_connect(
         self, ssh_host, ssh_user, ssh_pass, db_host, db_port, db_user, db_pass, db_name
@@ -125,3 +135,11 @@ def call_sp_retrieve(self, procname, args):
         if result == []:
             raise ISPyBNoResultException
         return result
+
+    def stop(self):
+        if self.server is not None:
+            self.server.stop()
+        self.server = None
+        self.conn = None
+        self.last_activity_ts = None
+        logger.debug("Server stopped")

api/security.py

@@ -92,6 +92,7 @@ def get_conn() -> Optional[Connector]:
     #          Assume the credentials are invalid if there is no host.
     #          If a host is not defined other properties are useless.
     if not credentials["host"]:
+        logger.debug("No ISPyB host - cannot return a connector")
         return None
 
     conn: Optional[Connector] = None
@@ -115,6 +116,21 @@ def get_configured_connector() -> Optional[Union[Connector, SSHConnector]]:
     return None
 
 
+def ping_configured_connector() -> bool:
+    """Pings the connector. If a connection can be obtained it is immediately closed.
+    The ping simply provides a way to check the credentials are valid and
+    a connection can be made.
+    """
+    conn: Optional[Union[Connector, SSHConnector]] = None
+    if connector == 'ispyb':
+        conn = get_conn()
+    elif connector == 'ssh_ispyb':
+        conn = get_remote_conn()
+        if conn is not None:
+            conn.stop()
+    return conn is not None
+
+
 class ISpyBSafeQuerySet(viewsets.ReadOnlyModelViewSet):
     def get_queryset(self):
         """

viewer/services.py

@@ -9,7 +9,7 @@
 from frag.utils.network_utils import get_driver
 from pydiscourse import DiscourseClient
 
-from api.security import get_configured_connector
+from api.security import ping_configured_connector
 from viewer.squonk2_agent import get_squonk2_agent
 
 logger = logging.getLogger(__name__)
@@ -156,7 +156,7 @@ def ispyb(func_id, name, ispyb_host=None) -> bool:
     del func_id, name, ispyb_host
 
     logger.debug("+ ispyb")
-    return get_configured_connector() != None
+    return ping_configured_connector()
 
 
 @service_query