topotato: better FRR startup exceptions

Getting FileNotFoundError is confusing, and having a separate exception for start failed also helps. Signed-off-by: David Lamparter <[email protected]>
opensourcerouting · Jul 10, 2024 · 633b84d · 633b84d
1 parent 8a2a016
commit 633b84d
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Showing 2 changed files with 42 additions and 10 deletions.
diff --git a/topotato/exceptions.py b/topotato/exceptions.py
@@ -58,9 +58,9 @@ class TopotatoLogFail(TopotatoFail):
     """
 
 
-class TopotatoDaemonCrash(TopotatoFail):
+class TopotatoDaemonErrors(TopotatoFail):
     """
-    Daemon exited/crashed unexpectedly.
+    Common base for unexpected things going on with a daemon process
     """
 
     def __init__(self, daemon: str, router: str, cmdline: Optional[str] = None):
@@ -87,7 +87,12 @@ def reprcrash(self) -> Optional["ReprFileLocation"]:
         def toterminal(self, tw: TerminalWriter) -> None:
             exc = self.excinfo.value
             tw.line("")
-            tw.sep(" ", f"{exc.daemon} crashed on {exc.router}", red=True, bold=True)
+            tw.sep(
+                " ",
+                f"{exc.daemon} {exc.topotato_kind} on {exc.router}",
+                red=True,
+                bold=True,
+            )
             if exc.cmdline:
                 tw.line("")
                 tw.line(f"started as: {exc.cmdline}")
@@ -96,6 +101,22 @@ def toterminal(self, tw: TerminalWriter) -> None:
                 tw.line(f"cause: {exc.__cause__!r}")
 
 
+class TopotatoDaemonCrash(TopotatoDaemonErrors):
+    """
+    Daemon exited/crashed unexpectedly.
+    """
+
+    topotato_kind = "crashed"
+
+
+class TopotatoDaemonStartFail(TopotatoDaemonErrors):
+    """
+    Daemon did not start correctly.
+    """
+
+    topotato_kind = "failed to start"
+
+
 class TopotatoDaemonStopFail(TopotatoFail):
     """
     Daemon did not stop when requested.

diff --git a/topotato/frr/core.py b/topotato/frr/core.py
@@ -49,6 +49,7 @@ def deprecated(fn):  # type: ignore
 from .livelog import LiveLog, LogMessage
 from ..exceptions import (
     TopotatoDaemonCrash,
+    TopotatoDaemonStartFail,
     TopotatoDaemonStopFail,
     TopotatoSkipped,
     TopotatoFail,
@@ -678,17 +679,27 @@ def start_daemon(self, daemon: str, defer_config=False):
         try:
             self.check_call(cmdline, pass_fds=[logfd.fileno()])
         except subprocess.CalledProcessError as e:
-            raise TopotatoDaemonCrash(
+            raise TopotatoDaemonStartFail(
                 daemon=daemon, router=self.name, cmdline=shlex.join(cmdline)
             ) from e
 
         # want record-priority & timestamp precision...
-        pid, _, _ = self.vtysh_polled(
-            self.instance.timeline,
-            daemon,
-            "enable\nconfigure\nlog file %s\ndebug memstats-at-exit\nend\nclear log cmdline-targets"
-            % self.logfiles[daemon],
-        )
+        try:
+            pid, _, _ = self.vtysh_polled(
+                self.instance.timeline,
+                daemon,
+                "enable\nconfigure\nlog file %s\ndebug memstats-at-exit\nend\nclear log cmdline-targets"
+                % self.logfiles[daemon],
+            )
+        except ConnectionRefusedError as e:
+            raise TopotatoDaemonStartFail(
+                daemon=daemon, router=self.name, cmdline=shlex.join(cmdline)
+            ) from e
+        except FileNotFoundError as e:
+            raise TopotatoDaemonStartFail(
+                daemon=daemon, router=self.name, cmdline=shlex.join(cmdline)
+            ) from e
+
         self.pids[daemon] = pid
 
         if not defer_config: