Load router extensions modules

app/conf.py

@@ -183,6 +183,11 @@ class ConfigurationContainer:
         default='300',
         factory=lambda x: int(x))
 
+    extension_modules: EnvVar = EnvVar(
+        key='EXTENSION_MODULES',
+        description="""Comma separated list of extension module names to load.""",
+        default=None)
+
     _environment_dict: Dict = os.environ
 
     _contextual_loader: Callable = None

app/extensions/README.md

+# Wellbore Domain Services Extensions
+
+
+> :warning: **This is an alpha feature**
+> Implementation changes are expected, and will not be announced.
+
+
+[[_TOC_]]
+
+## Use cases
+### Include new routers
+1. Add a new directory `<extension package name>/routers` under `app/extensions`
+2. Add a new python module `<router module name>.py`
+```
+/wellbore-domain-services
+ - app
+  |- extensions
+    |- <extension package name>
+       |- __init__.py
+       |- routers
+          |- <router module name>.py
+          |- __init__.py
+```
+3. In `<router module name>.py` include the following global variables.
+```python
+from fastapi import APIRouter
+
+router = APIRouter()
+router_prefix = '<extension router prefix>'
+router_tags = ['<extension router tags>']
+```
+4. Include new service endpoints to `router` in `<router module name>.py`.
+   - Use `@router.[get|post|delete|put|patch|...]` fastapi decorator to include new methods to the router
+   - Check WDMS routers implementation under `app/routers`
+   - The same pattern is encouraged to be used in the extension routers.
+   
+```python
+from fastapi import APIRouter, Depends, status
+from app.utils import Context, get_ctx
+from app.model.model_curated import *
+from app.clients.storage_service_client import get_storage_record_service
+from app.model.model_utils import from_record
+
+router = APIRouter() # From previous step
+
+# E.g.: Including a GET method API
+@router.get('/markers/{marker_id}',
+            response_model=marker,
+            summary="Get the marker using wks:marker:1.0.4 schema",
+            description="""Get the Marker object using its **id**.""",
+            operation_id="get_marker",
+            responses={status.HTTP_404_NOT_FOUND: {"description": "marker not found"}},
+            response_model_exclude_unset=True)
+async def get_marker(
+        marker_id: str,
+        ctx: Context = Depends(get_ctx)
+) -> marker:
+    storage_client = await get_storage_record_service(ctx)
+    marker_record = await storage_client.get_record(id=marker_id, data_partition_id=ctx.partition_id)
+    return from_record(marker, marker_record)
+```
+
+5. Include the full router module name in `EXTENSION_MODULES` environment variable
+E.g.: `app.extensions.<extension package name>.routers.<router module name>`
+
+
+6. Update the deployment scripts accordingly.
+
+  
+7. Run WDMS service, and check in the logs for the messages 
+```
+Loading `app.extensions.<extension package>.routers.<router module>` extension
+	Done. `app.extensions.<extension package>.routers.<router module>` loaded
+```
+
+8. Verify the new API endpoints were added under the provided tag, 
+   and with the given prefix. `https://{base_url}/api/os-wellbore-ddms/docs/{Tag}` 
+
+9. Include test
+   - Unit tests are to be placed under `tests/unit/extensions/<extension package name>`
+   - Integration tests are to be placed under `tests/integration/functional/extensions/<extension package name>`
+
+#### Troubleshooting
+##### A. Wrong router module configuration
+
+Check step #3 above
+```shell
+Loading `app.extensions.{}.routers.{}` extension
+	Failed to load `app.extensions.{}.routers.{}` extension. 
+	Module not configured properly. module 'app.extensions.{}.routers.{}' has no attribute 'router_prefix'
+```
+##### B. Wrong module name
+
+Review steps #2 and #4 above
+```shell
+Loading `app.extensions.{}.routers.{}` extension
+	Failed to load `app.extensions.{}.routers.{}` extension. 
+	Module not found. 
+	No module named 'app.extensions.{}.routers.{}'
+```
+##### C. Trailing comma in `EXTENSION_MODULES` list
+
+Review step #4 above, make sure there is no trailing comma in the `EXTENSION_MODULES` list.
+```shell
+Loading `` extension
+	Failed to load `` extension. Empty module name
+```

app/wdms_app.py

@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import sys
 
 from fastapi import FastAPI, Depends
 from fastapi.openapi.utils import get_openapi
@@ -42,6 +43,9 @@ from app.routers.search import search, fast_search
 from app.clients import StorageRecordServiceClient, SearchServiceClient
 from app.utils import get_http_client_session, OpenApiHandler, get_wdms_temp_dir
 
+import importlib
+
+
 base_app = FastAPI()
 
 
@@ -189,3 +193,28 @@ wdms_app.add_middleware(CreateBasicContextMiddleware, injector=app_injector)
 
 # adding exception handling
 add_exception_handlers(wdms_app)
+
+# Load extensions [alpha version]
+discovered_extensions = []
+
+extension_modules = Config.extension_modules.value
+if extension_modules:
+    discovered_extensions = extension_modules.split(',')
+
+for name in discovered_extensions:
+    try:
+        print(f'Loading `{name}` extension')
+        module = importlib.import_module(name)
+        wdms_app.include_router(module.router, prefix=module.router_prefix, tags=module.router_tags,
+                                dependencies=[
+                                    Depends(require_data_partition_id, use_cache=False),
+                                    Depends(require_opendes_authorized_user, use_cache=False)])
+        print(f'\tDone. `{name}` loaded')
+    except AttributeError as error:
+        print(f'\tFailed to load `{name}` extension. Module not configured properly. {error}')
+    except ModuleNotFoundError as error:
+        print(f'\tFailed to load `{name}` extension. Module not found. {error}')
+    except ValueError as error:
+        print(f'\tFailed to load `{name}` extension. {error}')
+    except:
+        print(f'\tFailed to load `{name}` extension. {sys.exc_info()[0]}')
\ No newline at end of file

devops/azure/chart/templates/configmap.yaml

@@ -23,6 +23,9 @@ data:
   USE_PARTITION_SERVICE: {{ .Values.configMap.data.usePartitionService }}
   AZ_LOGGER_LEVEL: {{ .Values.configMap.data.loggerLevel }}
   ENVIRONMENT_NAME: {{ .Values.configMap.data.environmentName }}
+  {{ if .Values.configMap.data.extensionModules }}
+  EXTENSION_MODULES: {{ .Values.configMap.data.extensionModules }}
+  {{ end }}
 kind: ConfigMap
 metadata:
   annotations: