Add support for distributed Cameras (#80)

* Big code dump from panoptes/POCS#547

* Fixing imports, paths, removed surplus camera tests

* Use right load_config, fix camera & aardvark tests

* Changes from review comments

* Move test_pyro_camera into test_huntsman.py, remove test_observatory.py

* Reduce duplication of code in camera creation

* Some missed tidying

* Small changes from re-review

.travis.yml

@@ -20,6 +20,10 @@ before_install:
   - pip install -r requirements.txt
   - python setup.py install
   - ln -s $TRAVIS_BUILD_DIR $PANDIR/huntsman-pocs
+  - ssh-keygen -b 2048 -t rsa -f ~/.ssh/id_rsa -N ''
+  - touch ~/.ssh/authorized_keys
+  - cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
+  - ssh-keyscan -H localhost >> ~/.ssh/known_hosts
 install:
   - cd $TRAVIS_BUILD_DIR
   - pip install -r requirements.txt

conf_files/pyro_camera.yaml

@@ -0,0 +1,99 @@
+# Config file for a distributed camera & focuser.
+#
+# Contains a default configuration with a simulated camera and focuser for testing
+# and example configurations for other camera and focusers (commented out).
+#
+# DO NOT EDIT THIS FILE, INSTEAD COPY ONE OF THE EXAMPLES TO pyro_camera_local.yaml
+# BEFORE EDITING AS REQUIRED.
+#
+# Simulated camera and focusers:
+name: camera.simulator.001
+host: localhost
+camera:
+  model: simulator
+  port: /dev/ttyFAKE01
+  set_point: 0
+  filter_type: r2_6
+  focuser:
+    model: simulator
+    port: /dev/ttyFAKE02
+    initial_position: 21706
+    autofocus_keep_files: False
+    autofocus_range:
+      - 50
+      - 250
+    autofocus_step:
+      - 5
+      - 25
+    autofocus_seconds: 1
+    autofocus_size: 500
+directories:
+    base: /var/panoptes
+    images: temp
+    data: data
+#
+# SBIG camera with Birger focuser:
+# name: camera.sbig.001
+# host: 999.999.999.999
+# camera:
+#   model: sbig
+#   port: 83F012345
+#   set_point: 0
+#   filter_type: r2_6
+#   focuser:
+#     model: birger
+#     port: 12345
+#     initial_position: 21706
+#     autofocus_keep_files: False
+#     autofocus_range:
+#       - 50
+#       - 250
+#     autofocus_step:
+#       - 5
+#       - 25
+#     autofocus_seconds: 1
+#     autofocus_size: 1000
+#
+# FLI camera with Birger focuser:
+# name: camera.fli.001
+# host: 999.999.999.999
+# camera:
+#   model: fli
+#   port: ML12345
+#   set_point: -10
+#   filter_type: r2_4
+#   focuser:
+#     model: birger
+#     port: 12345
+#     initial_position: 21706
+#     autofocus_keep_files: False
+#     autofocus_range:
+#       - 50
+#       - 250
+#     autofocus_step:
+#       - 5
+#       - 25
+#     autofocus_seconds: 1
+#     autofocus_size: 1000
+#
+# FLI Camera with FocusLynx focuser:
+# name: camera.fli.002
+# host: 999.999.999.999
+# camera:
+#   model: fli
+#   port: ML12345
+#   set_point: -10
+#   filter_type: g2_0
+#   focuser:
+#     model: focuslynx
+#     port: /dev/ttyFAKE
+#     initial_position: 21706
+#     autofocus_keep_files: False
+#     autofocus_range:
+#       - 50
+#       - 250
+#     autofocus_step:
+#       - 5
+#       - 25
+#     autofocus_seconds: 1
+#     autofocus_size: 1000

huntsman/camera/__init__.py

@@ -0,0 +1,171 @@
+from collections import OrderedDict
+import re
+import shutil
+import subprocess
+
+import Pyro4
+
+from pocs.utils import error
+from pocs.utils import load_module
+
+from huntsman.utils import load_config
+
+from pocs.camera import list_connected_cameras
+from pocs.camera import create_cameras_from_config as create_local_cameras
+from pocs.camera.camera import AbstractCamera  # pragma: no flakes
+from pocs.camera.camera import AbstractGPhotoCamera  # pragma: no flakes
+
+from huntsman.camera.pyro import Camera as PyroCamera
+
+from pocs.utils import logger as logger_module
+
+
+def list_distributed_cameras(ns_host=None, logger=None):
+    """Detect distributed cameras.
+
+    Looks for a Pyro name server and queries it for the list of registered cameras.
+
+    Args:
+        host (str, optional): hostname or IP address of the name server host. If not given
+            will attempt to locate the name server via UDP network broadcast.
+        logger (logging.Logger, optional): logger to use for messages, if not given will
+            use the root logger.
+
+    Returns:
+        dict: Dictionary of detected distributed camera name, URI pairs
+    """
+    if not logger:
+        logger = logger_module.get_root_logger()
+
+    try:
+        # Get a proxy for the name server (will raise NamingError if not found)
+        with Pyro4.locateNS(host=ns_host) as name_server:
+            # Find all the registered POCS cameras
+            camera_uris = name_server.list(metadata_all={'POCS', 'Camera'})
+            camera_uris = OrderedDict(sorted(camera_uris.items(), key=lambda t: t[0]))
+            n_cameras = len(camera_uris)
+            if n_cameras > 0:
+                msg = "Found {} distributed cameras on name server".format(n_cameras)
+                logger.debug(msg)
+            else:
+                msg = "Found name server but no distributed cameras"
+                logger.warning(msg)
+    except Pyro4.errors.NamingError as err:
+        msg = "Couldn't connect to Pyro name server: {}".format(err)
+        logger.warning(msg)
+        camera_uris = OrderedDict()
+
+    return camera_uris
+
+
+def create_cameras_from_config(config=None, logger=None, **kwargs):
+    """Create camera object(s) based on the config.
+
+    Creates a camera for each camera item listed in the config. Ensures the
+    appropriate camera module is loaded.
+
+    Args:
+        **kwargs (dict): Can pass a `cameras` object that overrides the info in
+            the configuration file. Can also pass `auto_detect`(bool) to try and
+            automatically discover the ports.
+
+    Returns:
+        OrderedDict: An ordered dictionary of created camera objects, with the
+            camera name as key and camera instance as value. Returns an empty
+            OrderedDict if there is no camera configuration items.
+
+    Raises:
+        error.CameraNotFound: Raised if camera cannot be found at specified port or if
+            auto_detect=True and no cameras are found.
+        error.PanError: Description
+    """
+    if not logger:
+        logger = logger_module.get_root_logger()
+
+    if not config:
+        config = load_config(**kwargs)
+
+    # Helper method to first check kwargs then config
+    def kwargs_or_config(item, default=None):
+        return kwargs.get(item, config.get(item, default))
+
+    camera_info = kwargs_or_config('cameras')
+    if not camera_info:
+        logger.info('No camera information in config.')
+        return OrderedDict()
+
+    try:
+        cameras = create_local_cameras(config=config, logger=logger, **kwargs)
+    except (error.PanError, KeyError, error.CameraNotFound):
+        logger.debug("No local cameras")
+        cameras = OrderedDict()
+
+    a_simulator = 'camera' in kwargs_or_config('simulator', default=list())
+    distributed_cameras = kwargs.get('distributed_cameras',
+                                     camera_info.get('distributed_cameras', False))
+    if not a_simulator and distributed_cameras:
+        logger.debug("Creating distributed cameras")
+        cameras.update(create_distributed_cameras(camera_info, logger=logger))
+
+    if len(cameras) == 0:
+        raise error.CameraNotFound(
+            msg="No cameras available. Exiting.", exit=True)
+
+    # Find primary camera
+    primary_camera = None
+    for camera in cameras.values():
+        if camera.is_primary:
+            primary_camera = camera
+
+    # If no camera was specified as primary use the first
+    if primary_camera is None:
+        camera_names = sorted(cameras.keys())
+        primary_camera = cameras[camera_names[0]]
+        primary_camera.is_primary = True
+
+    logger.debug("Primary camera: {}", primary_camera)
+    logger.debug("{} cameras created", len(cameras))
+
+    return cameras
+
+
+def create_distributed_cameras(camera_info, logger=None):
+    """Create distributed camera object(s) based on detected cameras and config
+
+    Creates a `pocs.camera.pyro.Camera` object for each distributed camera detected.
+
+    Args:
+        camera_info: 'cameras' section from POCS config
+        logger (logging.Logger, optional): logger to use for messages, if not given will
+            use the root logger.
+
+    Returns:
+        OrderedDict: An ordered dictionary of created camera objects, with the
+            camera name as key and camera instance as value. Returns an empty
+            OrderedDict if no distributed cameras are found.
+    """
+    if not logger:
+        logger = logger_module.get_root_logger()
+
+    # Get all distributed cameras
+    camera_uris = list_distributed_cameras(ns_host=camera_info.get('name_server_host', None),
+                                           logger=logger)
+
+    # Create the camera objects.
+    # TODO: do this in parallel because initialising cameras can take a while.
+    cameras = OrderedDict()
+    primary_id = camera_info.get('primary', '')
+    for cam_name, cam_uri in camera_uris.items():
+        logger.debug('Creating camera: {}'.format(cam_name))
+        cam = PyroCamera(name=cam_name, uri=cam_uri)
+        is_primary = ''
+        if primary_id == cam.uid or primary_id == cam.name:
+            cam.is_primary = True
+            is_primary = ' [Primary]'
+
+        logger.debug("Camera created: {} {}{}".format(
+            cam.name, cam.uid, is_primary))
+
+        cameras[cam_name] = cam
+
+    return cameras