feat: add overlord_overlord.py, update camera_overlord.py to be compa…

…tible (#74)

* feat: add overlord_lord.py, update camera_overlord.py to be compatible

* style: add comments to overlord_overlord.py

client/drivers/camera_overlord.py

@@ -1,31 +1,48 @@
-# This script periodically takes photos and saves them to
-# a temporary file on ram. This allows multiple programs to
-# access the camera feed at once.
+"""
+This script periodically takes photos and saves them to a temporary file on ram. This
+allows multiple programs to access the camera feed at once.
 
-from picamera2 import Picamera2
+Exits gracefully with status INTERRUPTED and closes the camera if a sigint is received.
+"""
+
+import logging
 import os
+import signal
 import time
+from enum import Enum
+
+from picamera2 import Picamera2
+
+
+class ExitCode(Enum):
+    INTERRUPTED = 1
+
 
-if __name__ == '__main__':
+logger = logging.getLogger(__name__)
+
+
+def handle_quit(signo, frame):
+    logger.info("Received SIGINT, quitting")
+    picam2.close()
+    quit(ExitCode.INTERRUPTED.value)
+
+
+if __name__ == "__main__":
     picam2 = Picamera2()
-    config = picam2.create_still_configuration({'size':(640,480)})
+    config = picam2.create_still_configuration({"size": (640, 480)})
     picam2.configure(config)
     picam2.start()
-    picam2.options['quality'] = 80
+    picam2.options["quality"] = 80
+
+    signal.signal(signal.SIGINT, handle_quit)
 
     try:
-        f = open('/tmp/snapshot.jpg','x')
+        f = open("/tmp/snapshot.jpg", "x")
         f.close()
-    except:
-        print('Snapshot already exists')
-
-    try:
-        while True:
-            picam2.capture_file("/tmp/snapshot2.jpg")
-            os.replace("/tmp/snapshot2.jpg", "/tmp/snapshot.jpg")
-            time.sleep(0.5)
-
-    except KeyboardInterrupt:
-        picam2.close()
-        print('Closed nicely')
-        quit()
+    except FileExistsError:
+        print("Snapshot already exists")
+
+    while True:
+        picam2.capture_file("/tmp/snapshot2.jpg")
+        os.replace("/tmp/snapshot2.jpg", "/tmp/snapshot.jpg")
+        time.sleep(0.5)

client/overlord_overlord.py

@@ -0,0 +1,50 @@
+"""
+One overlord to rule them all...
+"""
+
+import logging
+import multiprocessing
+import os
+import signal
+import subprocess
+
+PYTHON_DEFAULT = "python3.10"
+PYTHON_CAMERA = "python3.11"
+
+
+def spawn_camera_overlord():
+    subprocess.run([PYTHON_CAMERA, "drivers/camera_overlord.py"])
+
+
+def spawn_pi_overlord():
+    subprocess.run([PYTHON_DEFAULT, "drivers/main.py"])
+
+
+def main():
+    logger = logging.getLogger(__name__)
+
+    # Spawn a new process to run the camera indefinitely
+    camera_overlord = multiprocessing.Process(target=spawn_camera_overlord, args=())
+    logger.info("Starting camera overlord")
+    camera_overlord.start()
+
+    # Spawn a new process to run the Raspberry Pi code
+    pi_overlord = multiprocessing.Process(target=spawn_pi_overlord, args=())
+    logger.info("Starting pi overlord")
+    pi_overlord.start()
+
+    # If the Pi process ever terminates, gracefully terminate the camera process
+    _, pi_overlord_wait_status = os.waitpid(pi_overlord.pid, 0)
+    pi_overlord_exit_code = os.waitstatus_to_exit_code(pi_overlord_wait_status)
+    logger.info(f"Reaped pi overlord with exit code {pi_overlord_exit_code}")
+
+    os.kill(camera_overlord.camerad, signal.SIGINT)
+    _, camera_overlord_wait_status = os.waitcamerad(camera_overlord.camerad, 0)
+    camera_overlord_exit_code = os.waitstatus_to_exit_code(camera_overlord_wait_status)
+    logger.info(f"Reaped camera overlord with exit code {camera_overlord_exit_code}")
+
+    logger.info("Exiting")
+
+
+if __name__ == "__main__":
+    main()