Add a way to discover Evas on your network programmatically

Author: LouisBrunner

.github/workflows/build.yml

@@ -12,27 +12,31 @@ jobs:
         python-version: [3.5, 3.6, 3.7]
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v1
+      uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install pipenv
       uses: dschep/install-pipenv-action@v1
     - name: Install dependencies
-      uses: "VaultVulp/action-pipenv@master"
+      uses: VaultVulp/action-pipenv@v2.0.1
       with:
         command: install --dev
     - name: Run linter
-      uses: "VaultVulp/action-pipenv@master"
+      uses: VaultVulp/action-pipenv@v2.0.1
       with:
-        command: run flake8
+        command: run lint
+    - name: Run type checker
+      uses: VaultVulp/action-pipenv@v2.0.1
+      with:
+        command: run type
     - name: Run tests
-      uses: "VaultVulp/action-pipenv@master"
+      uses: VaultVulp/action-pipenv@v2.0.1
       with:
         command: run test --cov=evasdk --cov-branch --cov-report=xml
     - name: Upload to codecov
-      uses: codecov/codecov-action@v1.0.3
+      uses: codecov/codecov-action@v1.0.7
       with:
         token: ${{secrets.CODECOV_TOKEN}}
         file: ./coverage.xml

.gitignore

@@ -5,3 +5,4 @@ build/
 dist/
 .pytest_cache
 *coverage*
+.mypy_cache

LICENSE

@@ -1,4 +1,4 @@
-   Copyright 2018 Automata Technologies Ltd
+   Copyright 2015-2020 Automata Technologies Ltd
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

Pipfile

@@ -6,15 +6,21 @@ name = "pypi"
 [packages]
 requests = "*"
 websockets = "*"
+zeroconf = "==0.27.1"
 
 [dev-packages]
 flake8 = "*"
 requests-mock = "*"
 pytest = "*"
 "pytest-cov" = "*"
+"pytest-flake8" = "*"
+"pytest-mypy" = "*"
+mypy = "*"
 
 [requires]
 
 [scripts]
-test = "python -m pytest tests/"
+test = "pipenv run testd tests/"
+testd = "python -m pytest --mypy --flake8"
 lint = "flake8"
+type = "mypy evasdk examples tests"

Pipfile.lock

@@ -162,7 +162,7 @@ $ pipenv run test
 
 # or to run a single test file:
 $ pipenv shell
-$ python -m pytest tests/<test-name>_test.py
+$ pipenv run testd tests/<test-name>_test.py
 
 # some test require supplying ip and token via the `--ip` and `--token` arguements:
 $ pipenv run test --ip 172.16.16.2 --token abc-123-def-456

README.md

@@ -0,0 +1,121 @@
+from typing import Callable
+from dataclasses import dataclass
+from threading import Condition
+from .Eva import Eva
+from zeroconf import ServiceBrowser, Zeroconf
+
+
+CHOREO_SERVICE = "_automata-eva._tcp.local."
+
+
+@dataclass
+class DiscoveredEva:
+    name: str
+    host: str
+
+    def connect(self, token) -> Eva:
+        return Eva(self.host, token)
+
+
+DiscoverCallback = Callable[[str, DiscoveredEva], None]
+
+
+class EvaDiscoverer:
+
+
+    def __init__(self, callback: DiscoverCallback, name: str = None):
+        self.name = name
+        self.callback = callback
+        self.zeroconf = None
+
+    def __enter__(self):
+        self.zeroconf = Zeroconf()
+        self.browser = ServiceBrowser(self.zeroconf, CHOREO_SERVICE, self)
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.zeroconf.close()
+
+    def __get_eva(self, zeroconf: Zeroconf, service_type: str, service_name: str):
+        info = zeroconf.get_service_info(service_type, service_name)
+        if info is None:
+            return None
+        return DiscoveredEva(host=info.server, name=info.properties[b'name'].decode("utf-8"))
+
+    def __filter_name(self, eva):
+        return self.name is not None and self.name != eva.name
+
+    def add_service(self, zeroconf: Zeroconf, service_type: str, service_name: str):
+        eva = self.__get_eva(zeroconf, service_type, service_name)
+        if eva is None or self.__filter_name(eva):
+            return
+        self.callback('added', eva)
+
+    def remove_service(self, zeroconf: Zeroconf, service_type: str, service_name: str):
+        eva = self.__get_eva(zeroconf, service_type, service_name)
+        if eva is None or self.__filter_name(eva):
+            return
+        self.callback('removed', eva)
+
+
+def __find_evas(callback: DiscoverCallback, timeout: float, name: str = None, condition: Condition = None):
+    if condition is None:
+        condition = Condition()
+    with EvaDiscoverer(name=name, callback=callback):
+        with condition:
+            condition.wait(timeout=timeout)
+
+
+def find_evas(timeout: float = 5):
+    """Blocks for `timeout` seconds and returns a dictionary of DiscoveredEva (with their names as key) discovered in that time"""
+    evas = {}
+
+    def __callback(event: str, eva: DiscoveredEva):
+        if event == 'added':
+            evas[eva.name] = eva
+        elif event == 'deleted':
+            del evas[eva.name]
+
+    __find_evas(callback=__callback, timeout=timeout)
+    return evas
+
+
+def find_eva(name: str, timeout: float = 5):
+    """Blocks for a maximum of `timeout` seconds and returns a DiscoveredEva if a robot named `name` was found, or `None`"""
+    eva = None
+    cv = Condition()
+
+    def __callback(event: str, eva_found: DiscoveredEva):
+        nonlocal eva
+        if event == 'added':
+            eva = eva_found
+            with cv:
+                cv.notify()
+
+    __find_evas(name=name, callback=__callback, timeout=timeout, condition=cv)
+    return eva
+
+
+def find_first_eva(timeout: float = 5):
+    """Blocks for a maximum of `timeout` seconds and returns a DiscoveredEva if one was found, or `None`"""
+    eva = None
+    cv = Condition()
+
+    def __callback(event: str, eva_found: DiscoveredEva):
+        nonlocal eva
+        if event == 'added' and eva is None:
+            eva = eva_found
+            with cv:
+                cv.notify()
+
+    __find_evas(callback=__callback, timeout=timeout, condition=cv)
+    return eva
+
+
+def discover_evas(callback: DiscoverCallback):
+    """Returns a context that will discovers robots until exited
+
+    It will call `callback` with 2 arguments: the event (either `added` or `removed`) and a Discovered Eva object
+
+    Note that `callback` will be called from another thread so you will need to ensure any data accessed there is done in a thread-safe manner
+    """
+    return EvaDiscoverer(callback=callback)

evasdk/EvaDiscoverer.py

@@ -77,3 +77,7 @@
     EvaValidationError, EvaAuthError, EvaAutoRenewError,
     EvaAdminError, EvaServerError)
 from .version import __version__
+from .EvaDiscoverer import (
+    DiscoverCallback, DiscoveredEva,
+    find_evas, find_eva, find_first_eva, discover_evas,
+)

evasdk/__init__.py

@@ -186,7 +186,7 @@ def gpio_get(self, pin, pin_type):
     def __globals_editing(self, keys, values):
         data = {'changes': []}
         if (isinstance(keys, list) and isinstance(values, list)):
-            [data['changes'].append({'key': c[0], 'value': c[1]}) for c in zip(keys, values)]
+            data['changes'] = [{'key': k, 'value': v} for k, v in zip(keys, values)]
         else:
             data['changes'].append({'key': keys, 'value': values})
         data = json.dumps(data)

evasdk/eva_http_client.py

@@ -0,0 +1,4 @@
+[mypy]
+
+[mypy-pytest.*]
+ignore_missing_imports = True

mypy.ini

@@ -15,7 +15,11 @@
     packages=setuptools.find_packages(),
     long_description=long_description,
     long_description_content_type="text/markdown",
-    install_requires=['requests', 'websockets'],
+    install_requires=[
+        'requests',
+        'websockets',
+        'zeroconf',
+    ],
     classifiers=[
         "Programming Language :: Python :: 3",
         "Development Status :: 4 - Beta",