Capturing logs from the device-under-test

You can configure the Stb-tester Node to capture logs from the device-under-test during test-runs and manual control recordings.

This is configured using a pytest fixture that allows you to run code before and after a test-run to start and stop log capture. Stb-tester will look in your test-pack at tests/conftest.py for a fixture called capture_dut_logs.

How you implement capture_dut_logs depends on the type of device you are testing, and other details of your system (for example, you might also want to capture server logs).

If your test-farm has many different types of devices, you can use stbt.get_config("device_under_test", "device_type") to check the device type, and start the appropriate log capture process. To configure the device_type of each Stb-tester Node in your test-farm, see Node-specific configuration files.

For example:

tests/conftest.py

import pytest
import stbt

@pytest.fixture(autouse=True)
def capture_dut_logs():
    device_type = stbt.get_config("device_under_test", "device_type", None)
    match device_type:
        case "firetv":
            # start adb capture here
            yield
            # stop adb capture here
        case "roku":
            # start roku capture here
            yield
            # stop roku capture here
        case _:
            print(f"No log capture for device type {device_type}.")
            yield

Note that conftest.py is a special file that pytest imports automatically. autouse=True means that every test will automatically use the fixture; you don’t have to explicitly request it in each test. For more information see pytest’s documentation on fixtures and conftest.py.

Android log capture

For Android devices you can use Stb-tester’s stbt.android.AdbDevice.logcat Python API to capture logs using adb logcat.

To save logs to a file called “logcat.log”, add this fixture to tests/conftest.py:

tests/conftest.py

import pytest
from stbt.android import AdbDevice

@pytest.fixture(autouse=True)
def capture_dut_logs():
    adb = AdbDevice()
    with adb.logcat("logcat.log"):
        yield

To save logcat logs inline into the Stb-tester log (so you can view it in Stb-tester’s Interactive log viewer with timestamps synchronised to the video recording) use this fixture:

tests/conftest.py

import pytest
from stbt.android import AdbDevice

@pytest.fixture(autouse=True)
def capture_dut_logs():
    # Print logcat logs to standard output; Stb-tester automatically timestamps
    # each line and saves it to "stbt.log". logcat's "brief" format disables
    # logcat's own timestamping, to avoid double timestamps.
    adb = AdbDevice()
    with adb.logcat(
            "/dev/stdout",
            ["-v", "brief", "-v", "color", "-v", "printable"]):
        yield

Roku log capture

Roku devices expose a debug console over the network. You can capture logs from this console using Stb-tester’s stbt.Roku.save_logs Python API. For example, add this fixture to tests/conftest.py:

tests/conftest.py

import pytest
import stbt

@pytest.fixture(autouse=True)
def capture_dut_logs():
    roku = stbt.Roku.from_config()
    with roku.save_logs("roku.log"):
        yield