Refactor the code structure

geospaas_harvesting/__init__.py

@@ -1,9 +1,12 @@
 """This module provides means to gather metadata about various datasets
 into the GeoSPaaS catalog
 """
+
+import importlib
 import logging.config
 import os
 import os.path
+import pkgutil
 import sys
 import yaml
 
@@ -20,3 +23,11 @@
 if logging_configuration:
     logging.config.dictConfig(logging_configuration)
     logging.captureWarnings(True)
+
+# import plugins
+discovered_plugins = {
+    name: importlib.import_module(name)
+    for finder, name, ispkg
+    in pkgutil.iter_modules()
+    if name.startswith('geospaas_harvesting_')
+}

geospaas_harvesting/config.py

@@ -1,28 +1,37 @@
 """Configuration management"""
+import importlib
 import logging
+import pkgutil
 
-import geospaas_harvesting.providers.aviso as providers_aviso
-import geospaas_harvesting.providers.base as providers_base
-import geospaas_harvesting.providers.ceda as providers_ceda
-import geospaas_harvesting.providers.cmems as providers_cmems
-import geospaas_harvesting.providers.copernicus_scihub as providers_copernicus_scihub
-import geospaas_harvesting.providers.earthdata_cmr as providers_earthdata_cmr
-import geospaas_harvesting.providers.erddap as providers_erddap
-import geospaas_harvesting.providers.ftp as providers_ftp
-import geospaas_harvesting.providers.http as providers_http
-import geospaas_harvesting.providers.jaxa as providers_jaxa
-import geospaas_harvesting.providers.local as providers_local
-import geospaas_harvesting.providers.metno as providers_metno
-import geospaas_harvesting.providers.noaa as providers_noaa
-import geospaas_harvesting.providers.podaac as providers_podaac
-import geospaas_harvesting.providers.resto as providers_resto
+import geospaas_harvesting
 from .arguments import ArgumentParser, BooleanArgument, DictArgument, ListArgument
+from .providers.base import Provider
 from .utils import read_yaml_file
 
 
+def import_provider_modules():
+    """Import provider classes from core modules and plugins"""
+    imported = []
+    for base_module in [geospaas_harvesting, *geospaas_harvesting.discovered_plugins.values()]:
+        for _, name, ispkg in pkgutil.iter_modules(base_module.__path__):
+            if name == 'providers':
+                providers = importlib.import_module(f"{base_module.__name__}.{name}")
+                imported.append(providers)
+                if ispkg:
+                    for _, provider_name, _ in pkgutil.iter_modules(providers.__path__):
+                        imported.append(
+                            importlib.import_module(f"{providers.__name__}.{provider_name}"))
+    return imported
+
+
+import_provider_modules()
 logger = logging.getLogger(__name__)
 
 
+class NoProviderFoundError(Exception):
+    """No provider class was found"""
+
+
 class Configuration():
     """Base class for configuration objects"""
 
@@ -57,23 +66,19 @@ class ProvidersArgument(DictArgument):
             'password': 'pass123'
     }
     """
-    provider_types = {
-        'aviso': providers_aviso.AVISOProvider,
-        'ceda': providers_ceda.CEDAProvider,
-        'cmems': providers_cmems.CMEMSProvider,
-        'copernicus_scihub': providers_copernicus_scihub.CopernicusScihubProvider,
-        'earthdata_cmr': providers_earthdata_cmr.EarthDataCMRProvider,
-        'ftp': providers_ftp.FTPProvider,
-        'gportal_ftp': providers_jaxa.GPortalProvider,
-        'http': providers_http.HTTPProvider,
-        'metno': providers_metno.METNOProvider,
-        'nansat': providers_local.NansatProvider,
-        'netcdf': providers_local.NetCDFProvider,
-        'noaa': providers_noaa.NOAAProvider,
-        'podaac': providers_podaac.PODAACProvider,
-        'resto': providers_resto.RestoProvider,
-        'tabledap': providers_erddap.ERDDAPTableProvider,
-    }
+    provider_classes = Provider.__subclasses__()
+
+    def __init__(self, name, **kwargs):
+        super().__init__(name, **kwargs)
+
+    def _find_provider(self, provider_type):
+        """Try to find a provider matching the `provider_type` in the
+        Provider subclasses
+        """
+        for provider_class in self.provider_classes:
+            if provider_class.type == provider_type:
+                return provider_class
+        raise NoProviderFoundError(f"No provider found of type {provider_type}")
 
     def parse(self, value):
         """Go through the list of provider settings and create the
@@ -84,15 +89,16 @@ def parse(self, value):
         for provider_name, provider_settings in providers_dict.items():
             try:
                 _providers[provider_name] = (
-                    self.provider_types[provider_settings['type']](
+                    self._find_provider(provider_settings['type'])(
                         name=provider_name,
                         **provider_settings,
                     ))
             except KeyError as error:
                 logger.error('Missing setting for provider: %s', error.args[0])
+            except NoProviderFoundError as error:
+                logger.error(error.args[0])
         return _providers
 
-
 class ProvidersConfiguration(Configuration):
     """Configuration manager for providers"""
 
@@ -110,7 +116,7 @@ class SearchConfiguration(Configuration):
 
     def __init__(self):
         self.providers = None
-        common_argument_parser = providers_base.Provider().search_parameters_parser
+        common_argument_parser = Provider().search_parameters_parser
         self.config_arguments_parser = ArgumentParser([
             DictArgument(
                 'common', argument_parser=common_argument_parser),

geospaas_harvesting/providers/aviso.py

@@ -6,6 +6,9 @@
 
 class AVISOProvider(TimeFilterMixin, Provider):
     """Provider for AVISO's Thredds"""
+
+    type = 'aviso'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = 'https://tds.aviso.altimetry.fr/thredds'

geospaas_harvesting/providers/ceda.py

@@ -9,6 +9,8 @@
 class CEDAProvider(TimeFilterMixin, Provider):
     """Provider for CEDA FTP server"""
 
+    type = 'ceda'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = "ftp://anon-ftp.ceda.ac.uk"

geospaas_harvesting/providers/cmems.py

@@ -21,6 +21,8 @@
 class CMEMSProvider(Provider):
     """Provider for CMEMS using the copernicusmarine package"""
 
+    type = 'cmems'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.search_parameters_parser.add_arguments([

geospaas_harvesting/providers/copernicus_scihub.py

@@ -17,6 +17,9 @@
 
 class CopernicusScihubProvider(Provider):
     """Provider for the Copernicus Scihub APIs"""
+
+    type = 'copernicus_scihub'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.search_url = 'https://apihub.copernicus.eu/apihub/search'

geospaas_harvesting/providers/earthdata_cmr.py

@@ -16,6 +16,9 @@ class EarthDataCMRProvider(Provider):
     properly validated because of the massive amount of collections
     available through this API. This needs to be refined.
     """
+
+    type = 'earthdata_cmr'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.search_url = 'https://cmr.earthdata.nasa.gov/search/granules.umm_json'

geospaas_harvesting/providers/erddap.py

@@ -6,6 +6,9 @@
 
 class ERDDAPTableProvider(Provider):
     """Provider for tabledap APIs"""
+
+    type = 'tabledap'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = kwargs['url'].rstrip('/')

geospaas_harvesting/providers/ftp.py

@@ -9,6 +9,8 @@
 class FTPProvider(TimeFilterMixin, Provider):
     """Generic FTP provider"""
 
+    type = 'ftp'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.search_parameters_parser.add_arguments([

geospaas_harvesting/providers/http.py

@@ -9,6 +9,8 @@
 class HTTPProvider(TimeFilterMixin, Provider):
     """Generic HTTP directory provider"""
 
+    type = 'http'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.search_parameters_parser.add_arguments([

geospaas_harvesting/providers/jaxa.py

@@ -9,6 +9,8 @@
 class GPortalProvider(TimeFilterMixin, Provider):
     """Provider for JAXA GPortal FTP server"""
 
+    type = 'gportal_ftp'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = "ftp://ftp.gportal.jaxa.jp"

geospaas_harvesting/providers/local.py

@@ -26,6 +26,8 @@ class NansatProvider(TimeFilterMixin, Provider):
     """Provider for local files with metadata provided by Nansat
     """
 
+    type = 'nansat'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.search_parameters_parser.add_arguments([
@@ -45,6 +47,8 @@ class NetCDFProvider(TimeFilterMixin, Provider):
     """Provider for local files with metadata extracted directly using
     """
 
+    type = 'netcdf'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.longitude_attribute = kwargs.get('longitude_attribute', 'LONGITUDE')

geospaas_harvesting/providers/metno.py

@@ -6,6 +6,9 @@
 
 class METNOProvider(TimeFilterMixin, Provider):
     """Provider for MET NO's Thredds"""
+
+    type = 'metno'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = 'https://thredds.met.no/thredds'

geospaas_harvesting/providers/noaa.py

@@ -9,6 +9,8 @@
 class NOAAProvider(TimeFilterMixin, Provider):
     """Provider for NOAA FTP servers"""
 
+    type = 'noaa'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = "ftp://{server}.ncep.noaa.gov"

geospaas_harvesting/providers/podaac.py

@@ -6,6 +6,9 @@
 
 class PODAACProvider(TimeFilterMixin, Provider):
     """Provider for PODAAC's OpenDAP"""
+
+    type = 'podaac'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = 'https://opendap.jpl.nasa.gov/opendap'

geospaas_harvesting/providers/resto.py

@@ -23,6 +23,8 @@ class RestoProvider(Provider):
     parameters are fetched from the API.
     """
 
+    type = 'resto'
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.url = kwargs['url'].rstrip('/')

tests/test_config.py

@@ -3,11 +3,8 @@
 import logging
 import unittest
 import unittest.mock as mock
-from datetime import datetime, timezone as tz
-from pathlib import Path
 
 import geospaas_harvesting.config as config
-import geospaas_harvesting.providers.base as providers_base
 import geospaas_harvesting.providers.podaac as providers_podaac
 import geospaas_harvesting.providers.cmems as providers_cmems
 import geospaas_harvesting.providers.resto as providers_resto
@@ -58,10 +55,17 @@ def test_parse(self):
                     name='cmems', username='user', password='pass'),
             })
 
-    def test_parse_error(self):
+    def test_parse_config_error(self):
         """Test error handling when parsing wrong configuration"""
         with self.assertLogs(config.logger, level=logging.ERROR):
-            _ = config.ProvidersArgument('providers').parse({'foo': {}})
+            config.ProvidersArgument('providers').parse({'foo': {}})
+
+    def test_parse_no_provider_found(self):
+        """Test error handling when no provider matches the requested
+        type
+        """
+        with self.assertLogs(config.logger, level=logging.ERROR):
+            config.ProvidersArgument('providers').parse({'foo': {'type': 'foo'}})
 
 
 class ProvidersConfigurationTestCase(unittest.TestCase):