python: start building a Python API for controlling VILLASnode

python/setup.py

@@ -43,6 +43,7 @@ setup(
         'Programming Language :: Python :: 3'
     ],
     install_requires = [
+        'requests'
     ],
     setup_requires = [
         'm2r'

python/villas/node/node.py

@@ -2,25 +2,96 @@ import json
 import tempfile
 import subprocess
 import logging
+import signal
+import requests
+import uuid
+import datetime
 
 LOGGER = logging.getLogger('villas.node')
 
 class Node(object):
 
-    def __init__(self, cfg):
-        self.config = cfg
+    def __init__(self, log_filename = None, config_filename = None, config = { }, api = 'http://localhost:8080', executable = 'villas-node', **kwargs):
+        self.config = config
+        self.config_filename = config_filename
+        self.log_filename = log_filename
+        self.api_endpoint = api
+        self.executable = executable
+
+        self.child = None
 
     def start(self):
         self.config_file = tempfile.NamedTemporaryFile(mode='w+', suffix='.json')
 
-        json.dump(self.config, self.config_file)
+        if self.config_filename:
+            with open(self.config_filename) as f:
+                self.config_file.write(f.read())
+        else:
+            json.dump(self.config, self.config_file)
+
         self.config_file.flush()
 
+        if self.log_filename is None:
+            now = datetime.datetime.now()
+            self.log_filename = now.strftime('villas-node_%Y-%m%-%d_%H-%M-%S.log')
+
+        self.log = open(self.log_filename, 'w+')
+
         LOGGER.info("Starting VILLASnode with config: %s", self.config_file.name)
 
-        self.child = subprocess.Popen(['villas-node', self.config_file.name])
+        self.child = subprocess.Popen([self.executable, self.config_file.name], stdout=self.log, stderr=self.log)
+
+    def pause(self):
+        self.child.send_signal(signal.SIGSTOP)
+
+    def resume(self):
+        self.child.send_signal(signal.SIGCONT)
 
     def stop(self):
-        self.child.kill()
+        self.child.send_signal(signal.SIGTERM)
         self.child.wait()
 
+        self.log.close()
+
+    def restart(self):
+        self.request('restart')
+
+    @property
+    def active_config(self):
+        resp = self.request('config')
+
+        return resp['response']
+
+    @property
+    def nodes(self):
+        return self.request('nodes')['response']
+
+    @property
+    def paths(self):
+        return self.request('paths')['response']
+
+    def request(self, action, req = None):
+        body = {
+            'action' : action,
+            'id' : str(uuid.uuid4())
+        }
+
+        if req is not None:
+            body['request'] = req
+
+        r = requests.post(self.api_endpoint + '/api/v1', json=body, timeout=1)
+
+        r.raise_for_status()
+
+        return r.json()
+
+    def get_version(self):
+            ver = subprocess.check_output([ self.executable, '-V'], )
+
+            return ver.decode('ascii').rstrip()
+
+    def is_running(self):
+        if self.child is None:
+            return False
+        else:
+            return self.child.poll() is None