fix(slurmctld,slurmd): correct typing for static checker

`ConfigData.get(...)` from `ops` returns a looser type than what's allowed
by pyright if we're passing the result off to `nhc.generate_config(...)`, so
we use `typing.cast(str, ...)` to ensure that the type of the output is just str.

Other changes:

- Removed stale TODO comment from development code.

Signed-off-by: Jason C. Nucciarone <[email protected]>

charms/slurmctld/src/charm.py

@@ -148,7 +148,7 @@ def _on_update_status(self, _: UpdateStatusEvent) -> None:
 
     def _on_show_current_config_action(self, event: ActionEvent) -> None:
         """Show current slurm.conf."""
-        event.set_results({"slurm.conf": str(self._slurmctld.config.get())})
+        event.set_results({"slurm.conf": str(self._slurmctld.config.load())})
 
     def _on_slurmrestd_available(self, event: SlurmrestdAvailableEvent) -> None:
         """Check that we have slurm_config when slurmrestd available otherwise defer the event."""

charms/slurmd/src/charm.py

@@ -5,7 +5,7 @@
 """Slurmd Operator Charm."""
 
 import logging
-from typing import Any, Dict
+from typing import Any, Dict, cast
 
 from interface_slurmctld import Slurmctld, SlurmctldAvailableEvent
 from ops import (
@@ -95,7 +95,9 @@ def _on_install(self, event: InstallEvent) -> None:
 
     def _on_config_changed(self, _: ConfigChangedEvent) -> None:
         """Handle charm configuration changes."""
-        if nhc_conf := self.model.config.get("nhc-conf"):
+        # Casting the type to str is required here because `get` returns a looser
+        # type than what `nhc.generate_config(...)` allows to be passed.
+        if nhc_conf := cast(str, self.model.config.get("nhc-conf", "")):
             if nhc_conf != self._stored.nhc_conf:
                 self._stored.nhc_conf = nhc_conf
                 nhc.generate_config(nhc_conf)

charms/slurmd/src/utils/nhc.py

@@ -19,7 +19,6 @@
 import tempfile
 import textwrap
 from pathlib import Path
-from typing import Optional
 
 _logger = logging.getLogger(__name__)
 
@@ -82,19 +81,14 @@ def get_config() -> str:
     return f"{target} not found."
 
 
-def generate_config(nhc_config: Optional[str] = None) -> None:
+def generate_config(nhc_config: str) -> None:
     """Generate new nhc.conf configuration file.
 
     Args:
-        nhc_config: Optional NHC configuration to override the default template.
+        nhc_config: NHC configuration to override default.
     """
-    target = Path("/etc/nhc/nhc.conf")
-    if not nhc_config:
-        template = Path(__file__).absolute().parent / "templates" / "nhc.conf.tmpl"
-        nhc_config = template.read_text()
-
     try:
-        target.write_text(nhc_config)
+        Path("/etc/nhc/nhc.conf").write_text(nhc_config)
     except FileNotFoundError as e:
         _logger.error(f"error rendering nhc.conf: {e}")
         raise