Merge pull request #13 from miracum/add-url-passthrough

feat: enable passthrough urls and resources

README.md

@@ -17,6 +17,7 @@
 | BA_USER_NAME | | BasicAuth username if required for the connection to the fhir server | |
 | BA_PASSWORD | | BasicAuth password if required for the connection to the fhir server | |
 | RESOURCE_CONFIG | | Multiline yaml, analogue to the resource config file | |
+| PASSTHROUGH_CONFIG | | Multiline yaml, analogue to the passthrough config file | |
 | PROVISION_CONFIG | | Multiline json, analogue to the provison config file | | 
 | SSL_CERT | | Certificate for https | |
 | SSL_KEY | | Key for https | |
@@ -77,7 +78,7 @@ Resources:
 ### Provision Configuration
 Provisions can be configured either before container startup in the config/general_provison_config.json or during runtime:
 Pass a List of provision codes in a json format based on the [MII Kerndatensatz](https://simplifier.net/packages/de.medizininformatikinitiative.kerndatensatz.consent/1.0.0-ballot1).
-Every Consent is required to have ALL provided provisions as a subset of its provisions. This structure is required for the preconfiguration as well as the parameter version.
+Every Patient is required to have ALL provided provisions as a subset of its provisions. This structure is required for the preconfiguration as well as the parameter version.
 
 #### Example:
 ```
@@ -94,3 +95,15 @@ Every Consent is required to have ALL provided provisions as a subset of its pro
     ]   
 }
 ```
+
+### Passthrough Configuration:
+Some Applications might require you to additionally access proprietary endpoints in the underlying FHIR-Server. Similar to the previous configuration this can be achieved through a yaml configuration, that can be provided via environment variable, as well as the passthrough_config.yml file. You only need to provide the URL in a example route "fhir.server.url:portURL". If the url contains the usual /fhir/ base it has to be supplied under Resources, where "fhir.server.url:port/fhir/Resource".
+
+#### Example:
+```
+URLs:
+  - "/metadata"
+  - "/test/echo"
+Resources:
+  - "metadata"
+```

facade_app/api.py

@@ -1,10 +1,24 @@
+import os, yaml
 from flask import Flask
 from flask_restful import Api
+from resources.fhir_facade_passthrough import FHIR_Facade_Passthrough
 from resources.fhir_facade_server import FHIR_Facade_Server
 
+temp = os.getenv("PASSTHROUGH_CONFIG", "")
+if temp != "":
+    pass_conf = yaml.safe_load(temp)
+else:
+    with open("../config/passthrough_config.yml") as cfgfile:
+        pass_conf = yaml.safe_load(cfgfile.read())
+
 app = Flask(__name__)
 api = Api(app)
 
 # set up web server at FACADE_URL+FACADE_PORT
-api.add_resource(FHIR_Facade_Server, '/fhir/<string:resource>', '/fhir/<string:resource>/<string:search>')
-
+api.add_resource(
+    FHIR_Facade_Server,
+    "/fhir/<string:resource>",
+    "/fhir/<string:resource>/<string:search>",
+)
+if len(pass_conf["URLs"]) > 0:
+    api.add_resource(FHIR_Facade_Passthrough, *pass_conf["URLs"])

facade_app/config/passthrough_config.yml

@@ -0,0 +1,8 @@
+# Add all endpoints and resources that are supposed to be passed through without consent checks
+# Endpoints that use the same /fhir/ base url as resources have to be added in the resources section
+# E.g. /fhir/metadata
+URLs:
+  - "/metadata"
+  - "/test/echo"
+Resources:
+  - "metadata"

facade_app/resources/fhir_facade_passthrough.py

@@ -0,0 +1,23 @@
+from resources.util.util_functions import get_passthrough_result
+from flask import request, Response
+from flask_restful import Resource
+
+
+def passthrough_handle_request(self, is_post):
+    params = request.args.copy()
+    headers = dict(request.headers)
+    data = bytes(request.data)
+
+    if is_post:
+        return get_passthrough_result(request.full_path, params, headers, data, True)
+    else:
+        return get_passthrough_result(request.full_path, params, headers, data, False)
+
+
+class FHIR_Facade_Passthrough(Resource):
+
+    def get(self):
+        return passthrough_handle_request(self, False)
+
+    def post(self):
+        return passthrough_handle_request(self, True)

facade_app/resources/fhir_facade_server.py

@@ -1,6 +1,7 @@
 import yaml, json, requests, os, math, time, multiprocessing, logging
 from requests.auth import HTTPBasicAuth
 from functools import partial
+from resources.fhir_facade_passthrough import passthrough_handle_request
 import uuid, shortuuid
 import flask
 from flask import request, Response
@@ -23,6 +24,14 @@
     with open("../config/resource_config.yml") as cfgfile:
         resource_config = yaml.safe_load(cfgfile)
 
+temp = os.getenv("PASSTHROUGH_CONFIG", "")
+if temp != "":
+    pass_config = yaml.safe_load(temp)
+else:
+    with open("../config/passthrough_config.yml") as cfgfile:
+        pass_config = yaml.safe_load(cfgfile)
+
+PASS_RESOURCES = pass_config["Resources"]
 RESOURCE_PATHS = resource_config["Resources"]
 LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO")
 
@@ -44,6 +53,9 @@ def handleRequest(self, resource, search=""):
     if resource == "Page" and "__page-id" in params:
         return getPage(params["__page-id"])
 
+    if resource in PASS_RESOURCES:
+        return passthrough_handle_request(self, False)
+
     # Return error code if request is invalid
     if search != "_search":
         return "Syntax error. Use the appropriate fhir-post-search syntax: .../fhir/type/_search"

facade_app/resources/util/util_functions.py

@@ -0,0 +1,45 @@
+import os, requests, json
+from requests.auth import HTTPBasicAuth
+
+
+def get_passthrough_result(url, params, headers, data, is_post):
+    SERVER_URL = os.getenv("FHIR_SERVER_URL", "")
+
+    s = requests.sessions.Session()
+    auth = HTTPBasicAuth(os.getenv("BA_USER_NAME", ""), os.getenv("BA_PASSWORD", ""))
+
+    # Merge params and jsondata
+    params["_format"] = "application/fhir+json"
+    try:
+        data = json.loads(data)
+        data.update(params)
+    except:
+        data = {}
+        data.update(params)
+
+    headers.update(
+        {
+            "Accept": "application/fhir+json",
+            "Content-Type": "application/x-www-form-urlencoded",
+        }
+    )
+
+    if is_post:
+        response = s.post(
+            SERVER_URL.replace("/fhir/", "") + url,
+            auth=auth,
+            headers=headers,
+            params=data,
+            verify=False,
+        ).json()
+
+    else:
+        response = s.get(
+            SERVER_URL.replace("/fhir/", "") + url,
+            auth=auth,
+            headers=headers,
+            params=data,
+            verify=False,
+        ).json()
+
+    return response