Fixing issue with machine name

armi/bookkeeping/report/reportingUtils.py

@@ -78,7 +78,7 @@ def _writeCaseInformation(o, cs):
             (Operator_ArmiCodebase, context.ROOT),
             (Operator_WorkingDirectory, os.getcwd()),
             (Operator_PythonInterperter, sys.version),
-            (Operator_MasterMachine, os.environ.get("COMPUTERNAME", "?")),
+            (Operator_MasterMachine, getNodeName()),
             (Operator_NumProcessors, context.MPI_SIZE),
             (Operator_Date, context.START_TIME),
         ]
@@ -235,6 +235,30 @@ def _writeReactorCycleInformation(o, cs):
     _writeReactorCycleInformation(o, cs)
 
 
+def getNodeName():
+    """Get the name of this comput node.
+
+    First, look in context.py. Then try various Linux tools. Then try Windows commands.
+
+    Returns
+    -------
+    str
+        Compute node name.
+    """
+    hostNames = [
+        context.MPI_NODENAME,
+        context.MPI_NODENAMES[0],
+        subprocess.run("hostname", capture_output=True, text=True, shell=True).stdout,
+        subprocess.run("uname -n", capture_output=True, text=True, shell=True).stdout,
+        os.environ.get("COMPUTERNAME", context.LOCAL),
+    ]
+    for nodeName in hostNames:
+        if nodeName and nodeName != context.LOCAL:
+            return nodeName
+
+    return context.LOCAL
+
+
 def _getSystemInfoWindows():
     """Get system information, assuming the system is Windows.
 

armi/bookkeeping/report/tests/test_report.py

@@ -25,6 +25,7 @@
 from armi.bookkeeping.report.reportingUtils import (
     _getSystemInfoLinux,
     _getSystemInfoWindows,
+    getNodeName,
     getSystemInfo,
     makeBlockDesignReport,
     setNeutronBalancesReport,
@@ -103,6 +104,15 @@ def test_getSystemInfo(self):
 
         self.assertGreater(len(out), sum(len(sstr) + 5 for sstr in substrings))
 
+    def test_getNodeName(self):
+        """Test that the getNodeName() method returns a non-empty string.
+
+        It is hard to know what string SHOULD be return here, and it would depend on how the OS is
+        set up on your machine or cluster. But this simple test needs to pass as-is on Windows
+        and Linux.
+        """
+        self.assertGreater(len(getNodeName()), 0)
+
 
 class TestReport(unittest.TestCase):
     def setUp(self):

armi/context.py

@@ -104,8 +104,9 @@ def setMode(cls, mode):
 # MPI_SIZE is the total number of CPUs
 MPI_RANK = 0
 MPI_SIZE = 1
-MPI_NODENAME = "local"
-MPI_NODENAMES = ["local"]
+LOCAL = "local"
+MPI_NODENAME = LOCAL
+MPI_NODENAMES = [LOCAL]
 
 
 try: