Peter van Arkel
86eee0f916
Add a scheduler helper that calculates the next due time for a cron-style schedule expression and surface that value on the dashboard and host detail pages. Show the latest run type in host summaries and backup trend tables so manual and scheduled backups are distinguishable in the Django UI. Keep the calculation derived from existing ScheduleConfig data without adding a migration.
100 lines
2.9 KiB
Python
100 lines
2.9 KiB
Python
from __future__ import annotations
|
|
|
|
from dataclasses import dataclass
|
|
from datetime import datetime, timedelta
|
|
|
|
|
|
@dataclass(frozen=True)
|
|
class CronSchedule:
|
|
minute: str
|
|
hour: str
|
|
day_of_month: str
|
|
month: str
|
|
day_of_week: str
|
|
|
|
|
|
def parse_cron_expr(expr: str) -> CronSchedule:
|
|
parts = expr.strip().split()
|
|
if len(parts) != 5:
|
|
raise ValueError("cron expression must have exactly 5 fields")
|
|
return CronSchedule(*parts)
|
|
|
|
|
|
def due_key(moment: datetime) -> str:
|
|
return moment.strftime("%Y%m%d%H%M")
|
|
|
|
|
|
def is_due(expr: str, moment: datetime) -> bool:
|
|
schedule = parse_cron_expr(expr)
|
|
cron_dow = (moment.weekday() + 1) % 7
|
|
return (
|
|
_field_matches(schedule.minute, moment.minute, 0, 59)
|
|
and _field_matches(schedule.hour, moment.hour, 0, 23)
|
|
and _field_matches(schedule.day_of_month, moment.day, 1, 31)
|
|
and _field_matches(schedule.month, moment.month, 1, 12)
|
|
and _field_matches(schedule.day_of_week, cron_dow, 0, 7, sunday_alias=True)
|
|
)
|
|
|
|
|
|
def next_due_after(expr: str, moment: datetime, *, max_days: int = 366) -> datetime | None:
|
|
parse_cron_expr(expr)
|
|
candidate = moment.replace(second=0, microsecond=0) + timedelta(minutes=1)
|
|
deadline = candidate + timedelta(days=max_days)
|
|
while candidate <= deadline:
|
|
if is_due(expr, candidate):
|
|
return candidate
|
|
candidate += timedelta(minutes=1)
|
|
return None
|
|
|
|
|
|
def _field_matches(field: str, value: int, min_value: int, max_value: int, sunday_alias: bool = False) -> bool:
|
|
for part in field.split(","):
|
|
if _part_matches(part.strip(), value, min_value, max_value, sunday_alias=sunday_alias):
|
|
return True
|
|
return False
|
|
|
|
|
|
def _part_matches(part: str, value: int, min_value: int, max_value: int, sunday_alias: bool) -> bool:
|
|
if not part:
|
|
return False
|
|
|
|
step = 1
|
|
base = part
|
|
if "/" in part:
|
|
base, step_s = part.split("/", 1)
|
|
if not step_s.isdigit():
|
|
return False
|
|
step = int(step_s)
|
|
if step <= 0:
|
|
return False
|
|
|
|
if base == "*":
|
|
start = min_value
|
|
end = max_value
|
|
elif "-" in base:
|
|
start_s, end_s = base.split("-", 1)
|
|
if not start_s.isdigit() or not end_s.isdigit():
|
|
return False
|
|
start = int(start_s)
|
|
end = int(end_s)
|
|
elif base.isdigit():
|
|
start = end = int(base)
|
|
else:
|
|
return False
|
|
|
|
values = _normalize_values(range(start, end + 1), sunday_alias=sunday_alias)
|
|
normalized_value = 0 if sunday_alias and value == 7 else value
|
|
if normalized_value not in values:
|
|
return False
|
|
return (normalized_value - min(values)) % step == 0
|
|
|
|
|
|
def _normalize_values(values: range, sunday_alias: bool) -> set[int]:
|
|
out: set[int] = set()
|
|
for value in values:
|
|
if sunday_alias and value == 7:
|
|
out.add(0)
|
|
else:
|
|
out.add(value)
|
|
return out
|