working on harmonia

tests/harmonia/test-script.py

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+import functools
+from pathlib import Path
+from pprint import pformat
+import shlex
+import textwrap
+import tomllib
+from typing import Any, cast, TYPE_CHECKING
+
+from beartype import beartype
+
+from test_driver.machine import Machine
+from test_driver.errors import RequestedAssertionFailed
+
+if TYPE_CHECKING:
+    global machine
+    machine = cast(Machine, ...)
+    assert machine.shell is not None
+
+ls = "eza -lah --color=always --group-directories-first"
+
+indent = functools.partial(textwrap.indent, prefix='  ')
+
+@beartype
+def run_log(machine: Machine, *commands: str, timeout: int | None = 60) -> str:
+    output = ""
+    for command in commands:
+        with machine.nested(f"must succeed: {command}"):
+            (status, out) = machine.execute(f"{command} | tee /dev/stderr", timeout=timeout)
+            if status != 0:
+                machine.log(f"output: {out}")
+                raise RequestedAssertionFailed(
+                    f"command `{command}` failed (exit code {status})",
+                )
+            output += out
+
+    return output
+
+@beartype
+def get_config_file() -> dict[str, Any]:
+    machine.wait_for_unit("harmonia.service")
+    pid = int(machine.get_unit_property("harmonia.service", "MainPID"))
+    env_lines: list[str] = machine.succeed(f"cat /proc/{pid}/environ").replace("\0", "\n").splitlines()
+    pairs: list[list[str]] = [line.split("=", maxsplit=1) for line in env_lines]
+    env = dict(pairs)
+
+    config_file = Path(env["CONFIG_FILE"])
+
+    machine.log(f"copying from VM: {config_file=}")
+    machine.copy_from_vm(config_file.as_posix())
+
+    config_file_path = machine.out_dir / config_file.name
+    with open(config_file_path, "rb") as f:
+        config_data = tomllib.load(f)
+
+    config_file_path.unlink()
+    return config_data
+
+machine.wait_for_unit("default.target")
+assert "lix" in machine.succeed("nix --version").lower()
+machine.log("INIT")
+
+# Config should have our initial values.
+config_toml = get_config_file()
+machine.log(f"config.toml BEFORE first rebuild (initial): {indent(pformat(config_toml))}")
+assert int(config_toml['workers']) == 4, f"{config_toml['workers']=} != 4"
+assert int(config_toml['max_connection_rate']) == 256, f"{config_toml['max_connection_rate']=} != 256"
+
+with machine.nested("must succeed: initial nixos-rebuild switch"):
+    machine.succeed("nixos-generate-config")
+    machine.succeed("mkdir -vp /etc/nixos")
+    # Dereference is required since that configuration.nix is probably a symlink to the store.
+    machine.succeed("cp -rv --dereference /run/current-system/sw/share/nixos/configuration.nix /etc/nixos/")
+    machine.succeed("env PAGER= nixos-rebuild switch --log-format raw-with-logs --fallback")
+
+# Config should not have changed.
+config_toml = get_config_file()
+machine.log(f"config.toml after first rebuild: {indent(pformat(config_toml))}")
+assert int(config_toml['workers']) == 4, f"{config_toml['workers']=} != 4"
+assert int(config_toml['max_connection_rate']) == 256, f"{config_toml['max_connection_rate']=} != 256"
+
+new_workers = 20
+expr = textwrap.dedent(f"""
+    let
+        nixos = import <nixpkgs/nixos> {{ }};
+    in nixos.config.dynamicism.doChange {{
+        option = "services.harmonia.settings.workers";
+        value = {new_workers};
+    }}
+""").strip()
+machine.succeed(rf"""
+    nix run --show-trace --log-format raw-with-logs --impure -E {shlex.quote(expr)}
+""".strip())
+
+# Workers, but not max connection rate, should have changed.
+config_toml = get_config_file()
+machine.log(f"config.toml after DYNAMIC ACTIVATION: {indent(pformat(config_toml))}")
+assert int(config_toml['workers']) == new_workers, f"{config_toml['workers']=} != {new_workers}"
+assert int(config_toml['max_connection_rate']) == 256, f"{config_toml['max_connection_rate']=} != 256"
+
+new_max_connection_rate = 100
+expr = textwrap.dedent(f"""
+    let
+        nixos = import <nixpkgs/nixos> {{ }};
+    in nixos.config.dynamicism.doChange {{
+        option = [ "services" "harmonia" "settings" "max_connection_rate" ];
+        value = {new_max_connection_rate};
+    }}
+""").strip()
+machine.succeed(rf"""
+    nix run --show-trace --log-format raw-with-logs --impure -E {shlex.quote(expr)}
+""".strip())
+
+# Max connection rate should have changed, but workers should have reverted.
+config_toml = get_config_file()
+machine.log(f"config_toml after SECOND dynamic activation: {indent(pformat(config_toml))}")
+assert int(config_toml['max_connection_rate']) == new_max_connection_rate, f"{config_toml['max_connection_rate']=} != {new_max_connection_rate}"
+
+# And this should set everything back.
+machine.succeed("env PAGER= nixos-rebuild switch --log-format raw-with-logs --fallback")
+machine.systemctl("restart harmonia.service")
+machine.wait_for_unit("harmonia.service")
+config_toml = get_config_file()
+machine.log(f"config_toml after NORMAL activation: {indent(pformat(config_toml))}")
+assert int(config_toml['max_connection_rate']) == 256, f'{config_toml["max_connection_rate"]=} != 256'
+assert int(config_toml['workers']) == 4, f'{config_toml["workers"]=} != 4'