Improve crontab fact and operation (pyinfra-dev#1193)

- fix environment variables in cron tab entries
- fix cron identification
- fix handling of multiple same commands in cron tabs

This is backwards compatible from a UX/operation API perspective. It is NOT backwards compatible from a strict types perspective.

pyinfra/facts/crontab.py

@@ -0,0 +1,189 @@
+import re
+from typing import Dict, List, Optional, TypedDict, Union
+
+from typing_extensions import NotRequired
+
+from pyinfra.api import FactBase
+from pyinfra.api.util import try_int
+
+
+class CrontabDict(TypedDict):
+    command: NotRequired[str]
+    # handles cases like CRON_TZ=UTC
+    env: NotRequired[str]
+    minute: NotRequired[Union[int, str]]
+    hour: NotRequired[Union[int, str]]
+    month: NotRequired[Union[int, str]]
+    day_of_month: NotRequired[Union[int, str]]
+    day_of_week: NotRequired[Union[int, str]]
+    comments: NotRequired[List[str]]
+    special_time: NotRequired[str]
+
+
+# for compatibility, also keeps a dict of command -> crontab dict
+class CrontabFile:
+    commands: List[CrontabDict]
+
+    def __init__(self, input_dict: Optional[Dict[str, CrontabDict]] = None):
+        super().__init__()
+        self.commands = []
+        if input_dict:
+            for command, others in input_dict.items():
+                val = others.copy()
+                val["command"] = command
+                self.add_item(val)
+
+    def add_item(self, item: CrontabDict):
+        self.commands.append(item)
+
+    def __len__(self):
+        return len(self.commands)
+
+    def __bool__(self):
+        return len(self) > 0
+
+    def items(self):
+        return {item.get("command") or item.get("env"): item for item in self.commands}
+
+    def get_command(
+        self, command: Optional[str] = None, name: Optional[str] = None
+    ) -> Optional[CrontabDict]:
+        assert command or name, "Either command or name must be provided"
+
+        name_comment = "# pyinfra-name={0}".format(name)
+        for cmd in self.commands:
+            if cmd.get("command") == command:
+                return cmd
+            if cmd.get("comments") and name_comment in cmd["comments"]:
+                return cmd
+        return None
+
+    def get_env(self, env: str) -> Optional[CrontabDict]:
+        for cmd in self.commands:
+            if cmd.get("env") == env:
+                return cmd
+        return None
+
+    def get(self, item: str) -> Optional[CrontabDict]:
+        return self.get_command(command=item, name=item) or self.get_env(item)
+
+    def __getitem__(self, item) -> Optional[CrontabDict]:
+        return self.get(item)
+
+    def __repr__(self):
+        return f"CrontabResult({self.commands})"
+
+    # noinspection PyMethodMayBeStatic
+    def format_item(self, item: CrontabDict):
+        lines = []
+        for comment in item.get("comments", []):
+            lines.append(comment)
+
+        if "env" in item:
+            lines.append(item["env"])
+        elif "special_time" in item:
+            lines.append(f"{item['special_time']} {item['command']}")
+        else:
+            lines.append(
+                f"{item['minute']} {item['hour']} "
+                f"{item['day_of_month']} {item['month']} {item['day_of_week']} "
+                f"{item['command']}"
+            )
+        return "\n".join(lines)
+
+    def __str__(self):
+        return "\n".join(self.format_item(item) for item in self.commands)
+
+    def to_json(self):
+        return self.commands
+
+
+_crontab_env_re = re.compile(r"^\s*([A-Z_]+)=(.*)$")
+
+
+class Crontab(FactBase[CrontabFile]):
+    """
+    Returns a dictionary of CrontabFile.
+
+    .. code:: python
+        # CrontabFile.items()
+        {
+            "/path/to/command": {
+                "minute": "*",
+                "hour": "*",
+                "month": "*",
+                "day_of_month": "*",
+                "day_of_week": "*",
+            },
+            "echo another command": {
+                "special_time": "@daily",
+            },
+        }
+        # or CrontabFile.to_json()
+        [
+            {
+               command: "/path/to/command",
+               minute: "*",
+               hour: "*",
+               month: "*",
+               day_of_month: "*",
+               day_of_week: "*",
+            },
+            {
+                "command": "echo another command
+                "special_time": "@daily",
+            }
+        ]
+    """
+
+    default = CrontabFile
+
+    def requires_command(self, user=None) -> str:
+        return "crontab"
+
+    def command(self, user=None):
+        if user:
+            return "crontab -l -u {0} || true".format(user)
+        return "crontab -l || true"
+
+    def process(self, output):
+        crons = CrontabFile()
+        current_comments = []
+
+        for line in output:
+            line = line.strip()
+            if not line or line.startswith("#"):
+                current_comments.append(line)
+                continue
+
+            if line.startswith("@"):
+                special_time, command = line.split(None, 1)
+                item = CrontabDict(
+                    command=command,
+                    special_time=special_time,
+                    comments=current_comments,
+                )
+                crons.add_item(item)
+
+            elif _crontab_env_re.match(line):
+                # handle environment variables
+                item = CrontabDict(
+                    env=line,
+                    comments=current_comments,
+                )
+                crons.add_item(item)
+            else:
+                minute, hour, day_of_month, month, day_of_week, command = line.split(None, 5)
+                item = CrontabDict(
+                    command=command,
+                    minute=try_int(minute),
+                    hour=try_int(hour),
+                    month=try_int(month),
+                    day_of_month=try_int(day_of_month),
+                    day_of_week=try_int(day_of_week),
+                    comments=current_comments,
+                )
+                crons.add_item(item)
+
+            current_comments = []
+        return crons

pyinfra/facts/server.py

@@ -5,14 +5,15 @@
 import shutil
 from datetime import datetime
 from tempfile import mkdtemp
-from typing import Dict, List, Optional, Union
+from typing import Dict, List, Optional
 
 from dateutil.parser import parse as parse_date
 from distro import distro
-from typing_extensions import NotRequired, TypedDict
+from typing_extensions import TypedDict
 
 from pyinfra.api import FactBase, ShortFactBase
 from pyinfra.api.util import try_int
+from pyinfra.facts import crontab
 
 ISO_DATE_FORMAT = "%Y-%m-%dT%H:%M:%S%z"
 
@@ -407,75 +408,9 @@ def process(self, output) -> list[str]:
         return groups
 
 
-class CrontabDict(TypedDict):
-    minute: NotRequired[Union[int, str]]
-    hour: NotRequired[Union[int, str]]
-    month: NotRequired[Union[int, str]]
-    day_of_month: NotRequired[Union[int, str]]
-    day_of_week: NotRequired[Union[int, str]]
-    comments: Optional[list[str]]
-    special_time: NotRequired[str]
-
-
-class Crontab(FactBase[Dict[str, CrontabDict]]):
-    """
-    Returns a dictionary of cron command -> execution time.
-
-    .. code:: python
-
-        {
-            "/path/to/command": {
-                "minute": "*",
-                "hour": "*",
-                "month": "*",
-                "day_of_month": "*",
-                "day_of_week": "*",
-            },
-            "echo another command": {
-                "special_time": "@daily",
-            },
-        }
-    """
-
-    default = dict
-
-    def requires_command(self, user=None) -> str:
-        return "crontab"
-
-    def command(self, user=None):
-        if user:
-            return "crontab -l -u {0} || true".format(user)
-        return "crontab -l || true"
-
-    def process(self, output):
-        crons: dict[str, CrontabDict] = {}
-        current_comments = []
-
-        for line in output:
-            line = line.strip()
-            if not line or line.startswith("#"):
-                current_comments.append(line)
-                continue
-
-            if line.startswith("@"):
-                special_time, command = line.split(None, 1)
-                crons[command] = {
-                    "special_time": special_time,
-                    "comments": current_comments,
-                }
-            else:
-                minute, hour, day_of_month, month, day_of_week, command = line.split(None, 5)
-                crons[command] = {
-                    "minute": try_int(minute),
-                    "hour": try_int(hour),
-                    "month": try_int(month),
-                    "day_of_month": try_int(day_of_month),
-                    "day_of_week": try_int(day_of_week),
-                    "comments": current_comments,
-                }
-
-            current_comments = []
-        return crons
+# for compatibility
+CrontabDict = crontab.CrontabDict
+Crontab = crontab.Crontab
 
 
 class Users(FactBase):