devmon cron: notification email off by default

src/rtgs_lab_tools/device_monitoring/README.md

@@ -50,7 +50,8 @@ The monitoring script runs from the lab's shared workspace on Bryan's scrontab:
 Paths are overridable from the scrontab environment (never from the credentials file):
 DEVICEMON_BASE_DIR, DEVICEMON_WORK_DIR, DEVICEMON_LOG_DIR, DEVICEMON_CREDS_FILE,
 DEVICEMON_RELEASE_FILE, DEVICEMON_SA_KEY, DEVICEMON_TOKEN_SECRET, DEVICEMON_PYTHON_MODULE
-(default `python3/3.12.4_anaconda2024.06-1_libmamba`), DEVICEMON_PYTHON (absolute path).
+(default `python3/3.12.4_anaconda2024.06-1_libmamba`), DEVICEMON_PYTHON (absolute path),
+DEVICEMON_EMAIL (`1` sends the notification email after each run; off by default).
 
 Ownership (the script refuses to run if the code side is group- or world-writable):
 ```

src/rtgs_lab_tools/device_monitoring/scheduled_device_monitoring.sh

@@ -31,6 +31,8 @@
 #                              `module load python` left /usr/bin/python3 = 3.6.8 on PATH)
 #   DEVICEMON_PYTHON           interpreter to build the venv with (absolute path); skips the
 #                              module lookup
+#   DEVICEMON_EMAIL            1 = send the notification email after each run; default off
+#                              (the dashboard is the place to look; Bryan, 2026-10-18)
 #
 # Paths (defaults = the lab's shared MSI workspace):
 #   DEVICEMON_BASE_DIR    /projects/standard/runck014/shared/device_monitoring
@@ -379,6 +381,12 @@ MONITOR_ARGS=(monitor)
 [ -z "$END_DATE" ] || MONITOR_ARGS+=("--end-date=$END_DATE")
 [ -z "$NODE_IDS" ] || MONITOR_ARGS+=("--node-ids=$NODE_IDS")
 [ "$PROJECT" = "ALL" ] || MONITOR_ARGS+=("--project=$PROJECT")
+if [ "${DEVICEMON_EMAIL:-0}" = "1" ]; then
+    log "Notification email: on (DEVICEMON_EMAIL=1)"
+else
+    MONITOR_ARGS+=("--no-email")
+    log "Notification email: off (set DEVICEMON_EMAIL=1 to send it)"
+fi
 
 # Pin one timestamp for the whole day and keep it across retries, so a retried
 # report replaces the rows of the attempt it is repeating. UTC throughout.

tests/device_monitoring/test_cron_script.py

@@ -209,6 +209,24 @@ def test_builds_lean_venv_and_runs_the_devmon_cli(ws):
     assert r.returncode == 0 and "-m pip" not in log.read_text()
 
 
+def test_email_off_by_default_and_opt_in(ws):
+    sha = release_with_requirements(ws)
+    log = ws["tmp"] / "py.log"
+    pin = f"devmon-v0.0.2 {sha}\n"
+
+    def monitor_call(**extra):
+        log.write_text("")
+        r = run(ws, pin, DEVICEMON_PYTHON=str(stub_python(ws)), STUB_LOG=str(log), **extra)
+        assert r.returncode == 0, r.stdout + r.stderr
+        calls = [c.split(" ", 1)[1] for c in log.read_text().splitlines()]
+        return [c for c in calls if ".cli monitor" in c][0], r.stdout
+
+    call, out = monitor_call()
+    assert call.endswith("--no-email") and "Notification email: off" in out
+    call, out = monitor_call(DEVICEMON_EMAIL="1")
+    assert "--no-email" not in call and "Notification email: on" in out
+
+
 def test_never_runs_install_sh_or_full_extras():
     text = SCRIPT.read_text()
     assert "bash install.sh" not in text and "[dev]" not in text and "[all]" not in text