flux-jobs: support new "inactive_reason" output field and "endreason" format

doc/man1/flux-jobs.rst

@@ -453,6 +453,13 @@ the state of the job or other context:
    Returns the job runtime for jobs in RUN state or later, otherwise the
    job duration (if set) is returned.
 
+**inactive_reason**
+   If the job is inactive, returns the reason that the job is no
+   longer active.  Generally speaking, will output "Exit", "Timeout",
+   "Canceled", or signal.  If available, other contextual information
+   will also be provided such as the exit ``returncode`` or
+   cancellation message.
+
 CONFIGURATION
 =============
 

src/bindings/python/flux/Makefile.am

@@ -6,6 +6,7 @@ nobase_fluxpy_PYTHON = \
 	message.py \
 	constants.py \
 	util.py \
+	compat36.py \
 	future.py \
 	memoized_property.py \
 	debugged.py \

src/bindings/python/flux/compat36.py

@@ -0,0 +1,79 @@
+###############################################################
+# Copyright 2023 Lawrence Livermore National Security, LLC
+# (c.f. AUTHORS, NOTICE.LLNS, COPYING)
+#
+# This file is part of the Flux resource manager framework.
+# For details, see https://github.com/flux-framework.
+#
+# SPDX-License-Identifier: LGPL-3.0
+###############################################################
+
+import signal
+
+
+# strsignal() is only available on Python 3.8 and up
+def strsignal(signum):
+    if signum == signal.SIGHUP:
+        return "Hangup"
+    elif signum == signal.SIGINT:
+        return "Interrupt"
+    elif signum == signal.SIGQUIT:
+        return "Quit"
+    elif signum == signal.SIGILL:
+        return "Illegal instruction"
+    elif signum == signal.SIGTRAP:
+        return "Trace/breakpoint trap"
+    elif signum == signal.SIGABRT or signum == signal.SIGIOT:
+        return "Aborted"
+    elif signum == signal.SIGBUS:
+        return "Bus error"
+    elif signum == signal.SIGFPE:
+        return "Floating point exception"
+    elif signum == signal.SIGKILL:
+        return "Killed"
+    elif signum == signal.SIGUSR1:
+        return "User defined signal 1"
+    elif signum == signal.SIGSEGV:
+        return "Segmentation Fault"
+    elif signum == signal.SIGUSR2:
+        return "User defined signal 2"
+    elif signum == signal.SIGPIPE:
+        return "Broken pipe"
+    elif signum == signal.SIGALRM:
+        return "Alarm clock"
+    elif signum == signal.SIGTERM:
+        return "Terminated"
+    # N.B. signal.SIGSTKFLT not defined until Python 3.11
+    elif "SIGSTKFLT" in dir(signal) and signum == signal.SIGSTKFLT:  # novermin
+        return "Stack fault"
+    elif signum == signal.SIGCHLD:
+        return "Child exited"
+    elif signum == signal.SIGCONT:
+        return "Continued"
+    elif signum == signal.SIGSTOP:
+        return "Stopped (signal)"
+    elif signum == signal.SIGTSTP:
+        return "Stopped"
+    elif signum == signal.SIGTTIN:
+        return "Stopped (tty input)"
+    elif signum == signal.SIGTTOU:
+        return "Stopped (tty output)"
+    elif signum == signal.SIGURG:
+        return "Urgent I/O condition"
+    elif signum == signal.SIGXCPU:
+        return "CPU time limit exceeded"
+    elif signum == signal.SIGXFSZ:
+        return "File size limit exceeded"
+    elif signum == signal.SIGVTALRM:
+        return "Virtual timer expired"
+    elif signum == signal.SIGPROF:
+        return "Profiling timer expired"
+    elif signum == signal.SIGWINCH:
+        return "Window changed"
+    elif signum == signal.SIGIO or signum == signal.SIGPOLL:
+        return "I/O possible"
+    elif signum == signal.SIGPWR:
+        return "Power failure"
+    elif signum == signal.SIGSYS:
+        return "Bad system call"
+    raise ValueError

src/bindings/python/flux/job/info.py

@@ -29,6 +29,13 @@
 except ImportError:
     SchedResourceList = None
 
+# strsignal() is only available in Python 3.8 and up.
+# flux-core's minimum is 3.6.  Use compat library if not available.
+try:
+    from signal import strsignal  # novermin
+except ImportError:
+    from flux.compat36 import strsignal
+
 
 def statetostr(stateid, fmt="L"):
     return raw.flux_job_statetostr(stateid, fmt).decode("utf-8")
@@ -541,6 +548,55 @@ def zero_remove(key):
 
         return result
 
+    @memoized_property
+    def inactive_reason(self):
+        """
+        Generate contextual exit reason based on how the job ended
+        """
+        state = str(self.state)
+        if state != "INACTIVE":
+            return ""
+        result = str(self.result)
+        if result == "CANCELED":
+            if (
+                self.exception.occurred
+                and self.exception.type == "cancel"
+                and self.exception.note
+            ):
+                return f"Canceled: {self.exception.note}"
+            else:
+                return "Canceled"
+        elif result == "FAILED":
+            # exception.type == "exec" is special case, handled by returncode
+            if (
+                self.exception.occurred
+                and self.exception.type != "exec"
+                and self.exception.severity == 0
+            ):
+                note = None
+                if self.exception.note:
+                    note = f" note={self.exception.note}"
+                return f'Exception: type={self.exception.type}{note or ""}'
+            elif self.returncode > 128:
+                signum = self.returncode - 128
+                try:
+                    sigdesc = strsignal(signum)
+                except ValueError:
+                    sigdesc = f"Signaled {signum}"
+                return sigdesc
+            elif self.returncode == 126:
+                return "Command invoked cannot execute"
+            elif self.returncode == 127:
+                return "command not found"
+            elif self.returncode == 128:
+                return "Invalid argument to exit"
+            else:
+                return f"Exit {self.returncode}"
+        elif result == "TIMEOUT":
+            return "Timeout"
+        else:
+            return f"Exit {self.returncode}"
+
 
 def job_fields_to_attrs(fields):
     # Note there is no attr for "id", it is always returned
@@ -593,6 +649,15 @@ def job_fields_to_attrs(fields):
         "dependencies": ("dependencies",),
         "contextual_info": ("state", "dependencies", "annotations", "nodelist"),
         "contextual_time": ("state", "t_run", "t_cleanup", "duration"),
+        "inactive_reason": (
+            "state",
+            "result",
+            "waitstatus",
+            "exception_occurred",
+            "exception_severity",
+            "exception_type",
+            "exception_note",
+        ),
         # Special cases, pointers to sub-dicts in annotations
         "sched": ("annotations",),
         "user": ("annotations",),
@@ -676,6 +741,7 @@ class JobInfoFormat(flux.util.OutputFormat):
         "dependencies": "DEPENDENCIES",
         "contextual_info": "INFO",
         "contextual_time": "TIME",
+        "inactive_reason": "INACTIVE-REASON",
         # The following are special pre-defined cases per RFC27
         "annotations.sched.t_estimate": "T_ESTIMATE",
         "annotations.sched.reason_pending": "REASON",

src/bindings/python/flux/util.py

@@ -360,6 +360,12 @@ def fsd(secs):
     return strtmp
 
 
+def empty_outputs():
+    localepoch = datetime.fromtimestamp(0.0).strftime("%FT%T")
+    empty = ("", "0s", "0.0", "0:00:00", "1970-01-01T00:00:00", localepoch)
+    return empty
+
+
 class UtilFormatter(Formatter):
     # pylint: disable=too-many-branches
 
@@ -439,8 +445,7 @@ def format_field(self, value, spec):
         # must be deferred to the UtilDatetetime format() method, since
         # that method will be called after this one:
         if spec.endswith("h") and not isinstance(value, UtilDatetime):
-            localepoch = datetime.fromtimestamp(0.0).strftime("%FT%T")
-            basecases = ("", "0s", "0.0", "0:00:00", "1970-01-01T00:00:00", localepoch)
+            basecases = empty_outputs()
             value = "-" if str(value) in basecases else str(value)
             spec = spec[:-1] + "s"
         retval = super().format_field(value, spec)
@@ -639,7 +644,7 @@ def filter_empty(self, items):
 
         #  Iterate over all items, rebuilding lst each time to contain
         #  only those fields that resulted in non-"empty" strings:
-        empty = ("", "0", "0s", "0.0", "0:00:00", "1970-01-01T00:00:00")
+        empty = empty_outputs()
         for item in items:
             lst = [x for x in lst if formatter.format(x["fmt"], item) in empty]
 

src/cmd/flux-jobs.py

@@ -60,6 +60,13 @@ class FluxJobsConfig(UtilConfig):
                 "{priority:<12} {state:<8.8} {dependencies}"
             ),
         },
+        "endreason": {
+            "description": "Show why each job ended",
+            "format": (
+                "{id.f58:>12} ?:{queue:<8.8} {username:<8.8} {name:<10.10+} "
+                "{status_abbrev:>2.2} {t_inactive!d:%b%d %R::>12h} {inactive_reason}"
+            ),
+        },
     }
 
     def __init__(self):

t/Makefile.am

@@ -266,6 +266,7 @@ TESTSCRIPTS = \
 	python/t0025-uri.py \
 	python/t0026-tree.py \
 	python/t0027-constraint-parser.py \
+	python/t0028-compat36.py \
 	python/t1000-service-add-remove.py
 
 if HAVE_FLUX_SECURITY

t/python/t0028-compat36.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+###############################################################
+# Copyright 2021 Lawrence Livermore National Security, LLC
+# (c.f. AUTHORS, NOTICE.LLNS, COPYING)
+#
+# This file is part of the Flux resource manager framework.
+# For details, see https://github.com/flux-framework.
+#
+# SPDX-License-Identifier: LGPL-3.0
+###############################################################
+
+import unittest
+import subflux  # To set up PYTHONPATH
+from pycotap import TAPTestRunner
+import signal
+import flux.compat36
+
+
+class TestCompat36(unittest.TestCase):
+    def test_strsignal(self):
+        # Cover getting all signals strings, sanity check
+        # values of most common ones.
+        # N.B. SIGSTKFLT not defined until Python 3.11, will get ValueError
+        for i in range(signal.SIGHUP, signal.SIGIO):
+            try:
+                desc = flux.compat36.strsignal(i)
+            except ValueError:
+                pass
+
+        self.assertEqual(flux.compat36.strsignal(signal.SIGHUP), "Hangup")
+        self.assertEqual(flux.compat36.strsignal(signal.SIGINT), "Interrupt")
+        self.assertEqual(flux.compat36.strsignal(signal.SIGKILL), "Killed")
+        self.assertEqual(flux.compat36.strsignal(signal.SIGSEGV), "Segmentation Fault")
+        self.assertEqual(flux.compat36.strsignal(signal.SIGTERM), "Terminated")
+
+    def test_strsignal_invalid(self):
+        gotvalueerror = False
+
+        try:
+            str = flux.compat36.strsignal(0)
+        except ValueError:
+            gotvalueerror = True
+
+        self.assertIs(gotvalueerror, True)
+
+
+if __name__ == "__main__":
+    unittest.main(testRunner=TAPTestRunner())