X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=docs%2F5_Component_Documentation%2F7_pyagl.md;h=40f0a538e522839d2689a487175cd4c27506d49a;hb=4d6b3f3501c136f56229ec0150ea20f441193af7;hp=6de0a07fa65a8c3cd4acbac37372436e71480fab;hpb=f81a7f42d8f10467108bab784117a380e0070ece;p=AGL%2Fdocumentation.git diff --git a/docs/5_Component_Documentation/7_pyagl.md b/docs/5_Component_Documentation/7_pyagl.md index 6de0a07..40f0a53 100644 --- a/docs/5_Component_Documentation/7_pyagl.md +++ b/docs/5_Component_Documentation/7_pyagl.md @@ -2,6 +2,249 @@ title: PyAGL --- -# PyAGL +# 0. Intro +## Main purpose +PyAGL was written to be used as a testing framework replacing the Lua afb-test one, +however the modules are written in a way that could be used as standalone utilities to query +and evaluate apis and verbs from the App Framework Binder services in AGL. + +## High level overview +Python compatibility: **Python 3.8 preferred**, **should** be compatible with **3.6** + +Initial development PyAGL was done with Python **3.6** in mind, heavily using f-strings and a few typings. As of writing this +documentation(June 3rd 2021), current stable AGL version is Koi 11.0.2 which has Python 3.8, and further development is +done using 3.8 and 3.9 runtimes although **no** version-specific features are used from later versions; +features **used** are kept within features offered by Python **3.8**. + +The test suite is written in a relatively standard way of extending **pytest** with a couple tweaks +tailored to Jenkins CI and LAVA for AGL with regards to output and timings/timeouts, and these tweaks +are enabled by running `pytest -L` in order to enable LAVA logging behavior. + +The way PyAGL works could be summarized in several bullets below: + +* `websockets` package is used to communicate to the services, `x-afb-ws-json1` is used as a subprotocol, +* base.py provides AGLBaseService to be extended for each service +* AGLBaseService has a `portfinder()` routine which will use `asyncssh` if used remotely, +to figure out the port of the service's websocket that is listening on. When this was implemented services had a hardcoded listening port, +and was often changed when a new service was introduced. If you specify port, pyagl will connect to it directly. If no port is specified and +portfinder() cannot find the process or listening port should throw an exception and exit. +* main() implementations in most PyAGL services' bindings are intended to be used as a convenient standalone utility to query verbs, although +not necessarily available. +* PyAGL bindings are organized in classes, method names and respective parameters mostly adhere to service verbs/apis described +per service in https://git.automotivelinux.org/apps/agl-service-*/about +For example, in https://git.automotivelinux.org/apps/agl-service-audiomixer/about/ the docs for the service describe 5 verbs - +subscribe, unsubscribe, list_controls, volume, mute - and their respective methods in audiomixer.py. +* as mentioned above `pytest` package is required for unit tests. +* `pytest-async` is needed by pytest to cooperate with asyncio +* `pytest-dependency` is used in cases where specific testing order is needed and used via decorators + +# 1. Using PyAGL +Command line execution is intended for debugging and quick evaluation. +There are few prerequisites to start using it. First, your AGL image **must** be bitbaked with **agl-devel** feature when sourcing __aglsetup.sh__; +if not - the running AGL instance won't have websocket services exposed to listening TCP ports and PyAGL will fail to connect. + +```bash +git clone "https://gerrit.automotivelinux.org/gerrit/src/pyagl" +``` +Preferably create a virtualenv and install the packages in the env +```bash +user@debian:~$ python3 -mvenv ~/.virtualenvs/aglenv +user@debian:~$ source ~/.virtualenvs/aglenv/bin/activate +(aglenv) user@debian:~$ pip install -r requirements.txt +``` +Hard requirements are asyncssh, websockets, pytest, pytest-dependency, pytest-async; the others in the file are dependencies of the mentioned packages. + +If you have installed PyAGL as python package or current working directory is in the project root: +``` +(aglenv) user@debian:~/pyagl$ python3 -m pyagl.services.audiomixer 192.168.234.34 --list_controls +``` +should produce the following or similar result depending on how many controls are exposed and which AGL version you are running: +``` +matching services: ['afm-service-agl-service-audiomixer--0.1--main@1001.service'] +Requesting list_controls with id 359450446 +[RESPONSE][Status: success][359450446][Info: None][Data: [{'control': 'Master Playback', 'volume': 1.0, 'mute': 0}, +{'control': 'Playback: Speech-Low', 'volume': 1.0, 'mute': 0}, {'control': 'Playback: Emergency', 'volume': 1.0, 'mute': 0}, +{'control': 'Playback: Speech-High', 'volume': 1.0, 'mute': 0}, {'control': 'Playback: Navigation', 'volume': 1.0, 'mute': 0}, +{'control': 'Playback: Multimedia', 'volume': 1.0, 'mute': 0}, {'control': 'Playback: Custom-Low', 'volume': 1.0, 'mute': 0}, +{'control': 'Playback: Communication', 'volume': 1.0, 'mute': 0}, {'control': 'Playback: Custom-High', 'volume': 1.0, 'mute': 0}]] +``` + +# 2. Running the tests + +## Markers +Before running the tests it must be noted that __Markers__ are metavariables applied to the tests which play important part +in the behavior of pyagl and add great flexibility when deciding which tests to run. +Each test suite usually have unambiguous marker and description in `pytest.ini` for the reason above. +The default markers are applied in the list variable `pytestmark` in the beginning of each test file. +Each test suite has at least 2 default markers. + +`pytest.mark.asyncio` is a special marker needed because we are running pytest in async mode, +and the other marker is the name of the testsuite - for example `pytest.mark.geoclue` is for `geoclue` tests. + +`pytest.mark.dependency` is another special marker used by the pytest-dependency library helping for +running tests in a particular order when a more complicated setup other than a fixture is needed for +a test or the setup itself is a test or sequence of tests. + +`pytest.mark.hwrequired` is a marker signifying that additional hardware is required for tests to be successful - e.g. bluetooth phonebook tests need a phone with a pbap profile connected + +`pytest.mark.internet` is a marker for tests which require internet connection + +As mentioned above, behavior of pytest is altered by the markers because pytest does expression matching by marker and test names for which suite to be run. +In the example below we select all internet requiring and subscription tests but skip those that require additional hardware. +If we have a match with `internet or subscribe` the test will be selected, but if the test has `hwrequired` will be skipped, otherwise deselected overall. +``` +h3ulcb:~# pyagl -vk "internet or subscribe and not hwrequired" +============================ test session starts ============================ +platform linux -- Python 3.8.2, pytest-5.3.5, py-1.8.1, pluggy-0.13.1 -- /usr/bin/python3 +cachedir: .pytest_cache +rootdir: /usr/lib/python3.8/site-packages/pyagl, inifile: pytest.ini +plugins: asyncio-0.10.0, dependency-0.5.1, reverse-1.0.1 +collected 218 items / 163 deselected / 55 selected + +test_bluetooth.py::test_subscribe_device_changes PASSED [ 1%] +... +test_radio.py::test_unsubscribe_all PASSED [ 90%] +test_signal_composer.py::test_subscribe SKIPPED [ 92%] +test_signal_composer.py::test_unsubscribe SKIPPED [ 94%] +test_weather.py::test_current_weather FAILED [ 96%] +test_weather.py::test_subscribe_weather PASSED [ 98%] +test_weather.py::test_unsubscribe_weather PASSED [100%] +==== 1 failed, 37 passed, 17 skipped, 163 deselected, 1 warning in 3.23s ==== + +``` + +## Locally - On the board itself +There is the /usr/bin/pyagl convenience wrapper script which invokes pytest +with the tests residing in `/usr/lib/python3.8/site-packages/pyagl/tests` which +also will pass all commandline arguments down to pytest + +```console +qemux86-64:~# pyagl +=================== test session starts ============================= +platform linux -- Python 3.8.2, pytest-5.3.5, py-1.8.1, pluggy-0.13.1 +rootdir: /usr/lib/python3.8/site-packages/pyagl, inifile: pytest.ini +plugins: dependency-0.5.1, asyncio-0.10.0, reverse-1.0.1 +collected 213 items + +test_audiomixer.py ....... [ 3%] +test_bluetooth.py ............xxxsxx [ 11%] +test_bluetooth_map.py .x.xs. [ 12%] +... +``` + +## Remotely +You must export `AGL_TGT_IP` environment variable first, containing a string with a reachable IP address +configured(either DHCP or static) on one of the interfeces on the AGL instance(board or vm) on your network. +`AGL_TGT_PORT` is not required, however can be exported to skip over connecting to the board via ssh first +in order to figure out the listening port of service. + +```console +user@debian:~$ source ~/.virtualenvs/aglenv/bin/activate +(pyagl) user@debian:~$ export AGL_TGT_IP=192.168.234.34 +(pyagl) user@debian:~$ cd pydev/pyagl/pyagl/tests +(pyagl) user@debian:~/pydev/pyagl/pyagl/tests$ pytest test_geoclue.py +========================= test session starts ========================= +platform linux -- Python 3.9.2, pytest-5.4.1, py-1.8.1, pluggy-0.13.1 +rootdir: /home/user/pydev/pyagl/pyagl, inifile: pytest.ini +plugins: dependency-0.5.1, asyncio-0.11.0 +collected 3 items + +test_geoclue.py ... [100%] +``` +# 3. Writing bindings and/or tests for new services +This assumes you have already went through ["3. Developer Guides > Creating a new service"](../3_Developer_Guides/2_Creating_a_New_Service.md). + +Templates directory contains barebone _cookiecutter_ templates to create your project. +If you do not intend to use cookiecutter, you need a simple service file in which you inherit AGLBaseService +from base.py. +You can take a look at pyagl/services/geoclue.py and pyagl/tests/test_geoclue.py which is probably the +simplest binding in PyAGL for a reference and example. All basic methods like +[send|receive|un/subscribe|portfinder] are implemented in the base class. +You would need to do minimal work to create new service binding from scratch and by example of the geoclue service you need to do the following: + +* do the basic imports +```python3 +from pyagl.services.base import AGLBaseService, AFBResponse +import asyncio +``` + +* inherit AGLBaseService and type in the service class member the service name presuming you are following the AGL naming convention: +(if your new service does not follow the convention, the portfider routine wont work and you'll have to specify service port manually) +```python3 +class GeoClueService(AGLBaseService): + service = 'agl-service-geoclue' +``` + +* if you intend to run the new service binding as a standalone utility, you might want to add your new options to the argparser +```python3 + parser = AGLBaseService.getparser() + parser.add_argument('--location', help='Get current location', action='store_true') +``` + +* override the __init__ method with the respective parameters as api(used in the binding) and systemd service slug +``` + def __init__(self, ip, port=None, api='geoclue'): + super().__init__(ip=ip, port=port, api=api, service='agl-service-geoclue') +``` + +* define your methods and send requests with .request() which prepares the data in a JSON format, request returns message id +``` + async def location(self): + return await self.request('location') +``` + +* get the raw response with data = await .response() or use .afbresponse() to get structured data + +PyAGL is written with asyncio so you'd need an event loop to get your code running. +Most modules have standalone CLI functionality, which is done via ArgumentParser and each module that +is CLI usable inherits static base parser and extends its arguments as shown in the example below: + +```python3 +async def main(loop): + args = GeoClueService.parser.parse_args() + gcs = await GeoClueService(args.ipaddr) + + if args.location: + msgid = await gcs.location() + print(f'Sent location request with messageid {msgid}') + print(await gcs.afbresponse()) + +if __name__ == '__main__': + loop = asyncio.get_event_loop() + loop.run_until_complete(main(loop)) +``` +`GeoClueService` will try to return an instance with connection to the service. It will throw an exception if it fails to do so. +`AGLBaseService.afbresponse()` method is a wrapper on top of .response() which will prepare, validate and format data for a convenient usage intended for CLI usage. +`AFBResponse.__str__` is also a convenience method to be able to print all relevant data in regarding state of the response. + +```console +(aglenv) user@debian:~$ python3 -m pyagl.services.geoclue 192.168.234.251 --location +matching services: ['afm-service-agl-service-geoclue--1.0--main.service'] +Sent location request with messageid 29188435 +[RESPONSE][Status: success][29188435][Info: GeoClue location data][Data: {'latitude': 42.6898421, 'longitude': 23.3099069, 'accuracy': 107.4702045}] +``` + + +# 4. Environment variables +The following environment variables are used in the PyAGL project: + +Variable | Description +--- | --- +**AGL_TGT_IP** | **required** +**AGL_TGT_PORT** | **optional**, when this is used portfinder() routine is skipped, attempts direct websocket connection to this port. +**AGL_TEST_TIMEOUT** | **optional**, over-ride the default 5 second timeout value for binding responses. This is useful in many cases where a long-standing request has taken place - e.g. importing few thousand entries from a phonebook +**AGL_AVAILABLE_INTERFACES** | **optional**, specify which of ethernet, wifi, and bluetooth interfaces are available. The value is a comma separated list, with a default value of "ethernet,wifi,bluetooth". +**AGL_BTMAP_RECIPIENT** | **optional**, when running Bluetooth MAP tests, this would be used as phone number to write text messages to. +**AGL_BTMAP_TEXT** | **optional**, when running Bluetooth MAP tests, messages will be composed with this text. +**AGL_CAN_INTERFACE** | **optional**, specify the CAN interface to use for CAN testing, default value is "can0". +**AGL_PBAP_PHONENUM** | **optional**, when running Bluetooth PBAP tests, this phone number will be used to .search(). +**AGL_PBAP_VCF** | **optional**, for the Bluetooh PBAP tests query a contact entry out of the phonebook. +**AGL_BT_TEST_ADDR** | **optional**, for the Bluetooth tests pair/connect/disconnect with an actual Bluetooth device(phone)'s address . The address should have the DBus address style as "dev_00_01_02_03_04_05" instead of a regular colon-separated MAC address. + +# 5. Debugging +PyAGL uses pythons logger library so you can rise the logging level and see the output from most of the modules, +but was disabled by default because of the massive amount of output produced. When the default logger is enabled +all other libraries will show their output with pyagl - e.g. websockets, asyncssh etc. + +README.md in the root directory of the project also contains useful information. -FIXME.