Add Multinode support (#17)

Bump to version 1.0.0 as it is now feature comparable
with its Polyscope 5 sister

Co-authored-by: Felix Exner <[email protected]>

Author: urrsk

.github/workflows/build-and-test.yml

@@ -3,14 +3,31 @@ name: Build and Test
 on:
   workflow_dispatch:
   pull_request:
-    branches:
-      - master
   push:
     branches:
       - master
 
 jobs:
-  build:
+  backend-test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.13'
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r external-control-backend/requirements.txt
+          pip install pytest
+      - name: Run backend tests
+        working-directory: external-control-backend/tests
+        run: pytest
+
+  build-frontend-and-test:
     runs-on: ubuntu-latest
 
     steps:
@@ -40,7 +57,26 @@ jobs:
       working-directory: external-control-frontend
       run: npm run test
 
-    - name: Upload build artifacts
+    # Store build artifacts as workflow artifacts (temporary)
+    - name: Store build artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: build-temp-artifacts
+        path: target/external-control-*.urcapx
+        if-no-files-found: error
+
+  upload-urcapx:
+    runs-on: ubuntu-latest
+    needs: [backend-test, build-frontend-and-test]  # Only runs if both jobs succeed
+
+    steps:
+    - name: Download build artifacts
+      uses: actions/download-artifact@v4
+      with:
+        name: build-temp-artifacts
+        path: target/
+
+    - name: Upload final artifacts
       uses: actions/upload-artifact@v4
       with:
         name: external-control-urcapx

external-control-backend/Dockerfile

@@ -1,17 +1,20 @@
-FROM python:3.11-alpine
+FROM python:3.13-alpine
+
+# # Create necessary directories and set permissions
+RUN mkdir -p /tmp && chmod 777 /tmp
 
 # Install Flask
 COPY requirements.txt ./
 RUN pip install --no-cache-dir -r requirements.txt
 
 # Copy the application into the image
-COPY src/* .
+COPY src/ ./
 
 # Tell Flask where to load the application from
-ENV FLASK_APP simple-rest-api.py
+ENV FLASK_APP simple_rest_api.py
 
 # Expose Flask's default port
 EXPOSE 5000
 
-# Run the REST service
-ENTRYPOINT ["flask", "run", "--host", "0.0.0.0", "--port", "5000"]
+# Run the REST service with Flask development server
+ENTRYPOINT ["python", "simple_rest_api.py"]

external-control-backend/requirements.txt

@@ -1,4 +1,3 @@
 # Flask Framework
-Flask==2.0.1
-flask-cors==3.0.10
-Werkzeug==2.2.2
+Flask>=2.2
+flask-cors>=3.0.10

external-control-backend/src/__init__.py

@@ -0,0 +1 @@
+# This file makes the src directory a package for Python imports.

external-control-backend/src/request_program.py

@@ -1,4 +1,5 @@
 import socket
+import time
 
 class RequestProgram(object):
     def __init__(self, port, robotIP):
@@ -49,33 +50,36 @@ def send_command(self, command: str):
             str: The program code received from the robot.
 
         Raises:
-            Exception: If the connection to the remote PC could not be established.
+            Exception: If the connection to the remote PC could not be established or no data is received.
         """
-
         program = ""
         timeout = 5
-        # Create a socket connection with the robot IP and port number defined above
-        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        s.connect((self.robotIP, self.port))
-        s.sendall(command.encode('us-ascii'))
-        s.settimeout(timeout)  # Set timeout for receiving data
-        
-        #Receive script code
-        raw_data = b""
-        while True:
-            try:
-                data = s.recv(1024)
-                if not data:
-                    break
-                
-                raw_data += data
-            
-            except socket.timeout:
-                break
-
-        program = raw_data.decode("us-ascii")
-
-        # Close the connection
-        s.close()
-
-        return program
+        try:
+            # Create a socket connection with the robot IP and port number defined above
+            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            s.settimeout(0.1)
+            s.connect((self.robotIP, self.port))
+            s.sendall(command.encode('us-ascii'))
+            # Receive script code
+            raw_data = b""
+            begin = time.time()
+            while True:
+                try:
+                    data = s.recv(1024)
+                    if not data:
+                        break  # Connection closed by the server
+                    raw_data += data
+                except socket.timeout:
+                    if raw_data != b"":
+                        print("Done receiving data")
+                        break
+                    elif time.time() - begin > timeout:
+                        s.close()
+                        raise Exception(f"Connection timeout")
+            program = raw_data.decode("us-ascii")
+            s.close()
+            if not bool(program and program.strip()):
+                raise Exception(f"Did not receive any script lines")
+            return program
+        except Exception as e:
+            raise Exception(f"Connectivity problem with {self.robotIP}:{self.port}: {e}")

external-control-backend/src/simple-rest-api.py

@@ -0,0 +1,99 @@
+import flask
+from flask import Flask, jsonify
+from flask_cors import CORS
+import request_program
+import socket
+import time
+import logging
+import sys
+
+# Configure logging
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
+    stream=sys.stdout
+)
+logger = logging.getLogger(__name__)
+
+command = "request_program\n"
+
+# Create a simple rest api with Flask (https://flask.palletsprojects.com/en/2.0.x/)
+app = Flask(__name__)
+CORS(app)
+
+# Log startup message
+logger.info("Starting Flask application...")
+logger.info(f"Server hostname: {socket.gethostname()}")
+logger.info(f"Server IP: {socket.gethostbyname(socket.gethostname())}")
+
+# Simple in-memory cache: {(port, robotIP): (timestamp, program)}
+program_cache = {}
+CACHE_TTL = 2  # seconds
+
+def split_program_sections(program_text):
+    preamble = ''
+    program_node = ''
+    header_start = '# HEADER_BEGIN'
+    header_end = '# HEADER_END'
+    start_idx = program_text.find(header_start)
+    end_idx = program_text.find(header_end)
+    if start_idx != -1 and end_idx != -1 and end_idx > start_idx:
+        end_idx += len(header_end)
+        preamble = program_text[start_idx:end_idx]
+        # Everything after header_end is the program node
+        program_node = program_text[end_idx:].lstrip('\n')
+    else:
+        # If no header, treat all as program_node
+        program_node = program_text
+    return preamble, program_node
+
+def get_cached_response(cache_key, now):
+    if cache_key in program_cache:
+        ts, json_str = program_cache[cache_key]
+        if now - ts < CACHE_TTL:
+            return flask.Response(json_str, mimetype='application/json')
+    return None
+
+def build_json_response(program, valid, status_text):
+    preamble, program_node = split_program_sections(program)
+    json_obj = {
+        "preamble": preamble,
+        "program_node": program_node,
+        "valid": valid,
+        "status": status_text
+    }
+    return flask.json.dumps(json_obj)
+
+def store_in_cache(cache_key, now, json_str, valid):
+    if valid:
+        program_cache[cache_key] = (now, json_str)
+
+@app.route('/<int:port>/<robotIP>/', methods=["GET"])
+def read_params(port, robotIP):
+    logger.info(f"Received request for port {port} and robot IP {robotIP}")
+    cache_key = (port, robotIP)
+    now = time.time()
+    cached_resp = get_cached_response(cache_key, now)
+    if cached_resp:
+        logger.info(f"Returning cached response for port {port} and robot IP {robotIP}")
+        return cached_resp
+    status = None
+    try:
+        logger.info(f"Connecting to robot at {robotIP}:{port}")
+        con = request_program.RequestProgram(port, robotIP)
+        program = con.send_command(command)
+        valid = bool(program and program.strip())
+        status = "ok"
+        logger.info(f"Successfully retrieved program from robot at {robotIP}:{port}")
+    except Exception as e:
+        program = ''
+        valid = False
+        status = str(e)
+        logger.error(f"Error connecting to robot at {robotIP}:{port}: {str(e)}")
+    json_str = build_json_response(program, valid, status)
+    store_in_cache(cache_key, now, json_str, valid)
+    return flask.Response(json_str, mimetype='application/json')
+
+if __name__ == '__main__':
+    logger.info("Flask application is ready to serve requests")
+    app.run(host='0.0.0.0', port=5000)

external-control-backend/src/simple_rest_api.py

@@ -0,0 +1,75 @@
+import sys, os
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '../src')))
+import pytest
+import socket
+from request_program import RequestProgram
+
+class DummySocket:
+    def __init__(self, responses=None, raise_timeout=False, raise_connect=False):
+        self.responses = responses or []
+        self.sent = []
+        self.closed = False
+        self.recv_calls = 0
+        self.raise_timeout = raise_timeout
+        self.raise_connect = raise_connect
+        self.timeout = None
+    def settimeout(self, timeout):
+        self.timeout = timeout
+    def connect(self, addr):
+        if self.raise_connect:
+            raise socket.error("connect error")
+    def sendall(self, data):
+        self.sent.append(data)
+    def recv(self, bufsize):
+        if self.raise_timeout:
+            raise socket.timeout("timed out")
+        if self.recv_calls < len(self.responses):
+            resp = self.responses[self.recv_calls]
+            self.recv_calls += 1
+            return resp
+        return b''
+    def close(self):
+        self.closed = True
+
+@pytest.fixture(autouse=True)
+def patch_socket(monkeypatch):
+    monkeypatch.setattr(socket, 'socket', lambda *a, **kw: DummySocket())
+
+def test_send_command_success(monkeypatch):
+    responses = [b'# HEADER_BEGIN\nheader\n# HEADER_END\n', b'print("hi")\n']
+    dummy = DummySocket(responses=responses)
+    monkeypatch.setattr(socket, 'socket', lambda *a, **kw: dummy)
+    rp = RequestProgram(1234, '127.0.0.1')
+    result = rp.send_command('request_program\n')
+    assert '# HEADER_BEGIN\nheader\n# HEADER_END' in result
+    assert 'print("hi")' in result
+    assert dummy.closed
+
+def test_send_command_no_data(monkeypatch):
+    dummy = DummySocket(responses=[])
+    monkeypatch.setattr(socket, 'socket', lambda *a, **kw: dummy)
+    rp = RequestProgram(1234, '127.0.0.1')
+    with pytest.raises(Exception) as exc:
+        rp.send_command('request_program\n')
+    assert (
+        'Connectivity problem with 127.0.0.1:1234: Did not receive any script lines' in str(exc.value)
+    )
+    assert dummy.closed
+
+def test_send_command_timeout(monkeypatch):
+    dummy = DummySocket(raise_timeout=True)
+    monkeypatch.setattr(socket, 'socket', lambda *a, **kw: dummy)
+    rp = RequestProgram(1234, '127.0.0.1')
+    with pytest.raises(Exception) as exc:
+        rp.send_command('request_program\n')
+    assert 'Connectivity problem with 127.0.0.1:1234: Connection timeout' in str(exc.value)
+    assert dummy.closed
+
+def test_send_command_connect_error(monkeypatch):
+    dummy = DummySocket(raise_connect=True)
+    monkeypatch.setattr(socket, 'socket', lambda *a, **kw: dummy)
+    rp = RequestProgram(1234, '127.0.0.1')
+    with pytest.raises(Exception) as exc:
+        rp.send_command('request_program\n')
+    assert 'connect error' in str(exc.value)
+    assert dummy.closed or not dummy.closed  # connect error may not close