Use self reported hostname and port when building URLs

In efforts to decrease the complexity of server configuration (see #48)
and to increase flexibility with DNS or IP addresses, we decided to
experiment with letting gunicorn/flask return with the URL root that was
used to make the request.

taky/dps/__init__.py

@@ -8,20 +8,14 @@
 load_config(os.environ.get("TAKY_CONFIG"))
 
 application = app = Flask(__name__)
-app.config["HOSTNAME"] = config.get("taky", "hostname")
 app.config["NODEID"] = config.get("taky", "node_id")
 app.config["UPLOAD_PATH"] = os.path.realpath(config.get("dp_server", "upload_path"))
 
-app.config["PUBLIC_IP"] = config.get("taky", "public_ip")
 app.config["COT_PORT"] = config.getint("cot_server", "port")
 if config.getboolean("ssl", "enabled"):
-    app.config["PROTO"] = "https://"
     app.config["COT_CONN_STR"] = 'ssl:{app.config["HOSTNAME"]}:{app.config["COT_PORT"]}'
-    app.config["DPS_PORT"] = 8443
 else:
-    app.config["PROTO"] = "http://"
     app.config["COT_CONN_STR"] = 'tcp:{app.config["HOSTNAME"]}:{app.config["COT_PORT"]}'
-    app.config["DPS_PORT"] = 8080
     # TODO: Configurable?
 
 from taky.dps import views  # pylint: disable=wrong-import-position

taky/dps/views/datapackage.py

@@ -12,11 +12,7 @@ def url_for(f_hash):
     """
     Returns the URL for the given hash
     """
-    proto = app.config["PROTO"]
-    ip_addr = app.config["PUBLIC_IP"]
-    port = app.config["DPS_PORT"]
-
-    return f"{proto}{ip_addr}:{port}/Marti/sync/content?hash={f_hash}"
+    return f"{request.host_url}Marti/sync/content?hash={f_hash}"
 
 
 def get_meta(f_hash=None, f_name=None):

taky/dps/views/version.py

@@ -1,3 +1,5 @@
+from flask import request
+
 from taky import __version__
 from taky.dps import app
 
@@ -9,13 +11,15 @@ def marti_api_version():
 
 @app.route("/Marti/api/version/config")
 def marti_api_version_config():
+    hostname = request.host.split(":")
+
     return {
         "version": "2",
         "type": "ServerConfig",
         "data": {
             "version": f"taky-{__version__}",
             "api": "2",
-            "hostname": app.config["HOSTNAME"],
+            "hostname": hostname[0],
         },
         "nodeId": app.config["NODEID"],
     }