computer-playbook/tests/unit/python/roles/sys-svc-container/test_sandbox_placement.py

import unittest
from pathlib import Path

from jinja2 import Environment, FileSystemLoader, StrictUndefined, select_autoescape

from utils import PROJECT_ROOT

TEMPLATES = Path(PROJECT_ROOT) / "roles" / "sys-svc-container" / "templates"

SANDBOX_LABEL = "kata-capable"


def _ansible_bool(value):
    if isinstance(value, bool):
        return value
    if value is None:
        return False
    if isinstance(value, str):
        return value.strip().lower() in {"y", "yes", "true", "on", "1"}
    return bool(value)


BASE = {
    "compose_mode": "swarm",
    "application_id": "web-app-hermes",
    "service_name": "hermes",
    "RUNTIME": "local",
    "SANDBOX_NODE_LABEL": SANDBOX_LABEL,
    "DOCKER_RESTART_POLICY": "unless-stopped",
    "RESOURCE_CPUS": "1",
    "RESOURCE_MEM_LIMIT": "1g",
    "RESOURCE_MEM_RESERVATION": "256m",
    "RESOURCE_PIDS_LIMIT": "512",
}


class TestSandboxPlacement(unittest.TestCase):
    def _render(
        self, kata_enabled, manager_placed=False, sandbox_tier=True, **overrides
    ):
        env = Environment(
            loader=FileSystemLoader(str(TEMPLATES)),
            trim_blocks=True,
            lstrip_blocks=False,
            undefined=StrictUndefined,
            autoescape=select_autoescape(),
        )
        env.filters["bool"] = _ansible_bool
        env.filters["resource_filter"] = lambda _apps, *_a, **_k: ""
        env.filters["swarm_restart_condition"] = lambda value: value

        def _lookup(name, *args, **kwargs):
            if name == "applications":
                return {}
            if name == "compose_replicas":
                return "replicas: 3"
            if name == "roles_with_placement":
                return ["web-app-hermes"] if manager_placed else []
            if name == "config":
                return kata_enabled
            raise AssertionError(f"unexpected lookup: {name}")

        env.globals["lookup"] = _lookup
        groups = {"svc-virt-kata": ["wrk-02"]} if sandbox_tier else {}
        return env.get_template("deploy.yml.j2").render(
            {**BASE, "groups": groups, **overrides}
        )

    def _constraints(self, rendered):
        lines = [line.strip() for line in rendered.splitlines()]
        return [line[2:] for line in lines if line.startswith("- node.")]

    def test_sandbox_consumer_is_pinned_to_a_sandbox_node(self):
        constraints = self._constraints(self._render(kata_enabled=True))
        self.assertIn(f"node.labels.{SANDBOX_LABEL} == true", constraints)

    def test_every_other_service_is_kept_off_the_sandbox_nodes(self):
        constraints = self._constraints(self._render(kata_enabled=False))
        self.assertIn(f"node.labels.{SANDBOX_LABEL} != true", constraints)

    def test_the_two_directions_are_mutually_exclusive(self):
        for enabled in (True, False):
            with self.subTest(kata_enabled=enabled):
                constraints = self._constraints(self._render(kata_enabled=enabled))
                self.assertEqual(len([c for c in constraints if SANDBOX_LABEL in c]), 1)

    def test_a_cluster_without_a_sandbox_tier_gets_no_sandbox_constraint(self):
        for enabled in (True, False):
            with self.subTest(kata_enabled=enabled):
                constraints = self._constraints(
                    self._render(kata_enabled=enabled, sandbox_tier=False)
                )
                self.assertEqual([c for c in constraints if SANDBOX_LABEL in c], [])

    def test_manager_placement_composes_with_the_sandbox_constraint(self):
        constraints = self._constraints(
            self._render(kata_enabled=False, manager_placed=True)
        )
        self.assertIn("node.role == manager", constraints)
        self.assertIn(f"node.labels.{SANDBOX_LABEL} != true", constraints)

    def test_manager_placement_survives_without_a_sandbox_tier(self):
        constraints = self._constraints(
            self._render(kata_enabled=False, manager_placed=True, sandbox_tier=False)
        )
        self.assertEqual(constraints, ["node.role == manager"])

    def test_compose_mode_emits_no_deploy_block(self):
        rendered = self._render(kata_enabled=True, compose_mode="compose")
        self.assertEqual(rendered.strip(), "")

    def test_a_failed_task_does_not_latch_the_rollout(self):
        """Swarm's default pauses forever on the first task that fails.

        With no failure_action, swarmkit applies pause at a max_failure_ratio
        of zero, so one transient failure stops the rollout for good and no
        step in the deploy resumes it. The restart policy replaces the task and
        the service ends up healthy, while the update status stays latched and
        the convergence check reports the deploy as failed.
        """
        rendered = self._render(kata_enabled=False)
        self.assertIn("failure_action: continue", rendered)


if __name__ == "__main__":
    unittest.main()