about summary refs log tree commit diff
path: root/nixpkgs/nixos/lib/test-driver/test_driver/driver.py
blob: 835d60ec3b4fd736dbc4fa22bce19f61edcda8b5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
from contextlib import contextmanager
from pathlib import Path
from typing import Any, Dict, Iterator, List, Union, Optional, Callable, ContextManager
import os
import re
import tempfile

from test_driver.logger import rootlog
from test_driver.machine import Machine, NixStartScript, retry
from test_driver.vlan import VLan
from test_driver.polling_condition import PollingCondition


def get_tmp_dir() -> Path:
    """Returns a temporary directory that is defined by TMPDIR, TEMP, TMP or CWD
    Raises an exception in case the retrieved temporary directory is not writeable
    See https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir
    """
    tmp_dir = Path(tempfile.gettempdir())
    tmp_dir.mkdir(mode=0o700, exist_ok=True)
    if not tmp_dir.is_dir():
        raise NotADirectoryError(
            f"The directory defined by TMPDIR, TEMP, TMP or CWD: {tmp_dir} is not a directory"
        )
    if not os.access(tmp_dir, os.W_OK):
        raise PermissionError(
            f"The directory defined by TMPDIR, TEMP, TMP, or CWD: {tmp_dir} is not writeable"
        )
    return tmp_dir


def pythonize_name(name: str) -> str:
    return re.sub(r"^[^A-z_]|[^A-z0-9_]", "_", name)


class Driver:
    """A handle to the driver that sets up the environment
    and runs the tests"""

    tests: str
    vlans: List[VLan]
    machines: List[Machine]
    polling_conditions: List[PollingCondition]

    def __init__(
        self,
        start_scripts: List[str],
        vlans: List[int],
        tests: str,
        out_dir: Path,
        keep_vm_state: bool = False,
    ):
        self.tests = tests
        self.out_dir = out_dir

        tmp_dir = get_tmp_dir()

        with rootlog.nested("start all VLans"):
            vlans = list(set(vlans))
            self.vlans = [VLan(nr, tmp_dir) for nr in vlans]

        def cmd(scripts: List[str]) -> Iterator[NixStartScript]:
            for s in scripts:
                yield NixStartScript(s)

        self.polling_conditions = []

        self.machines = [
            Machine(
                start_command=cmd,
                keep_vm_state=keep_vm_state,
                name=cmd.machine_name,
                tmp_dir=tmp_dir,
                callbacks=[self.check_polling_conditions],
                out_dir=self.out_dir,
            )
            for cmd in cmd(start_scripts)
        ]

    def __enter__(self) -> "Driver":
        return self

    def __exit__(self, *_: Any) -> None:
        with rootlog.nested("cleanup"):
            for machine in self.machines:
                machine.release()

    def subtest(self, name: str) -> Iterator[None]:
        """Group logs under a given test name"""
        with rootlog.nested("subtest: " + name):
            try:
                yield
                return True
            except Exception as e:
                rootlog.error(f'Test "{name}" failed with error: "{e}"')
                raise e

    def test_symbols(self) -> Dict[str, Any]:
        @contextmanager
        def subtest(name: str) -> Iterator[None]:
            return self.subtest(name)

        general_symbols = dict(
            start_all=self.start_all,
            test_script=self.test_script,
            machines=self.machines,
            vlans=self.vlans,
            driver=self,
            log=rootlog,
            os=os,
            create_machine=self.create_machine,
            subtest=subtest,
            run_tests=self.run_tests,
            join_all=self.join_all,
            retry=retry,
            serial_stdout_off=self.serial_stdout_off,
            serial_stdout_on=self.serial_stdout_on,
            polling_condition=self.polling_condition,
            Machine=Machine,  # for typing
        )
        machine_symbols = {pythonize_name(m.name): m for m in self.machines}
        # If there's exactly one machine, make it available under the name
        # "machine", even if it's not called that.
        if len(self.machines) == 1:
            (machine_symbols["machine"],) = self.machines
        vlan_symbols = {
            f"vlan{v.nr}": self.vlans[idx] for idx, v in enumerate(self.vlans)
        }
        print(
            "additionally exposed symbols:\n    "
            + ", ".join(map(lambda m: m.name, self.machines))
            + ",\n    "
            + ", ".join(map(lambda v: f"vlan{v.nr}", self.vlans))
            + ",\n    "
            + ", ".join(list(general_symbols.keys()))
        )
        return {**general_symbols, **machine_symbols, **vlan_symbols}

    def test_script(self) -> None:
        """Run the test script"""
        with rootlog.nested("run the VM test script"):
            symbols = self.test_symbols()  # call eagerly
            exec(self.tests, symbols, None)

    def run_tests(self) -> None:
        """Run the test script (for non-interactive test runs)"""
        self.test_script()
        # TODO: Collect coverage data
        for machine in self.machines:
            if machine.is_up():
                machine.execute("sync")

    def start_all(self) -> None:
        """Start all machines"""
        with rootlog.nested("start all VMs"):
            for machine in self.machines:
                machine.start()

    def join_all(self) -> None:
        """Wait for all machines to shut down"""
        with rootlog.nested("wait for all VMs to finish"):
            for machine in self.machines:
                machine.wait_for_shutdown()

    def create_machine(self, args: Dict[str, Any]) -> Machine:
        tmp_dir = get_tmp_dir()

        if args.get("startCommand"):
            start_command: str = args.get("startCommand", "")
            cmd = NixStartScript(start_command)
            name = args.get("name", cmd.machine_name)
        else:
            cmd = Machine.create_startcommand(args)  # type: ignore
            name = args.get("name", "machine")

        return Machine(
            tmp_dir=tmp_dir,
            out_dir=self.out_dir,
            start_command=cmd,
            name=name,
            keep_vm_state=args.get("keep_vm_state", False),
        )

    def serial_stdout_on(self) -> None:
        rootlog._print_serial_logs = True

    def serial_stdout_off(self) -> None:
        rootlog._print_serial_logs = False

    def check_polling_conditions(self) -> None:
        for condition in self.polling_conditions:
            condition.maybe_raise()

    def polling_condition(
        self,
        fun_: Optional[Callable] = None,
        *,
        seconds_interval: float = 2.0,
        description: Optional[str] = None,
    ) -> Union[Callable[[Callable], ContextManager], ContextManager]:
        driver = self

        class Poll:
            def __init__(self, fun: Callable):
                self.condition = PollingCondition(
                    fun,
                    seconds_interval,
                    description,
                )

            def __enter__(self) -> None:
                driver.polling_conditions.append(self.condition)

            def __exit__(self, a, b, c) -> None:  # type: ignore
                res = driver.polling_conditions.pop()
                assert res is self.condition

            def wait(self, timeout: int = 900) -> None:
                def condition(last: bool) -> bool:
                    if last:
                        rootlog.info(f"Last chance for {self.condition.description}")
                    ret = self.condition.check(force=True)
                    if not ret and not last:
                        rootlog.info(
                            f"({self.condition.description} failure not fatal yet)"
                        )
                    return ret

                with rootlog.nested(f"waiting for {self.condition.description}"):
                    retry(condition, timeout=timeout)

        if fun_ is None:
            return Poll
        else:
            return Poll(fun_)