correctly reading environment variables in conf

.github/workflows/ci.yml

@@ -42,6 +42,7 @@ jobs:
         command:
           - "-m eoxserver.services.ows.wps.test_data_types"
           - "-m eoxserver.services.ows.wps.test_allowed_values"
+          - "-m eoxserver.core.test_config"
           - "manage.py test --pythonpath=./eoxserver/ eoxserver.core -v2"
           - "manage.py test --pythonpath=./eoxserver/ eoxserver.backends -v2"
           - "manage.py test --pythonpath=./eoxserver/ eoxserver.services -v2"

autotest/autotest/conf/eoxserver.conf

@@ -40,7 +40,7 @@ instance_id=autotest
 [services.owscommon]
 #http_service_url    (mandatory) the URL where GET KVP and POST XML
 #                                OWS requests are expected
-http_service_url=http://testserver/ows
+http_service_url = ${DEFAULT:HTTP_SERVICE_URL}
 
 # time_interval_interpretation (optional) How to interpret time intervals.
 #                                         Allowed values are 'closed' and
@@ -101,6 +101,8 @@ supported_formats=image/png,image/jpeg,image/gif,image/tiff
 
 mask_names=clouds
 
+# min_render_zoom = ${DEFAULT:OWS_WMS_MINRENDER_ZOOM}
+
 [services.ows.wcs]
 
 # CRSes supported by WCS (EPSG code; uncomment to set non-default values)

eoxserver/core/config.py

@@ -32,16 +32,14 @@
 """
 
 import imp
+import os
 from os.path import join, getmtime
 from sys import prefix
 import threading
 import logging
 from time import time
 
-try:
-    from ConfigParser import RawConfigParser
-except ImportError:
-    from configparser import RawConfigParser
+from configparser import ConfigParser, ExtendedInterpolation
 
 
 from django.conf import settings
@@ -55,8 +53,18 @@
 _last_access_time = None
 
 
+# NOTE: Previously these values were hardcoded in the config.
+#       Now they are interpolated from env vars, but we keep
+#       these defautls here for backwards compatibility
+DEFAULTS = {
+    "HTTP_SERVICE_URL": "http://localhost:8000/ows?",
+    "OWS_WCS_MAXSIZE": "2048",
+    "OWS_WMS_MINRENDER_ZOOM": "",
+}
+
+
 def get_eoxserver_config():
-    """ Returns the EOxServer config as a :class:`ConfigParser.RawConfigParser`
+    """ Returns the EOxServer config as a :class:`ConfigParser.ConfigParser`
     """
     with config_lock:
         if not _cached_config or \
@@ -68,7 +76,7 @@ def get_eoxserver_config():
 
 def reload_eoxserver_config():
     """ Triggers the loading or reloading of the EOxServer config as a
-        :class:`ConfigParser.RawConfigParser`.
+        :class:`configparser.ConfigParser`.
     """
     global _cached_config, _last_access_time
     _, eoxs_path, _ = imp.find_module("eoxserver")
@@ -83,8 +91,17 @@ def reload_eoxserver_config():
         % ("Rel" if _cached_config else "L", ", ".join(paths))
     )
 
+    env_vars = {
+        **DEFAULTS,
+        **os.environ,
+    }
+
     with config_lock:
-        _cached_config = RawConfigParser()
+        _cached_config = ConfigParser(
+            env_vars,
+            allow_no_value=True,
+            interpolation=ExtendedInterpolation(),
+        )
         _cached_config.read(paths)
         _last_access_time = time()
 

eoxserver/core/test_config.py

@@ -0,0 +1,37 @@
+import os
+from unittest import mock
+
+from django.test import TestCase
+
+from eoxserver.core.config import get_eoxserver_config, reload_eoxserver_config
+from eoxserver.services.ows.wms.layermapper import LayerMapperConfigReader
+
+
+class TestConfig(TestCase):
+    def test_config_interpolates_env_vars(self):
+        new_url = "https://example.com/myows"
+        # force reload because it's cached
+        with mock.patch.dict(os.environ, {"HTTP_SERVICE_URL": new_url}):
+            reload_eoxserver_config()
+            current_config = get_eoxserver_config()
+
+        self.assertEqual(
+            current_config.get("services.owscommon", "http_service_url"),
+            new_url,
+        )
+
+    def test_config_has_default_values(self):
+        reload_eoxserver_config()
+        current_config = get_eoxserver_config()
+        self.assertEqual(
+            current_config.get("services.owscommon", "http_service_url"),
+            "http://localhost:8000/ows?",
+        )
+
+    def test_config_handles_empty_values(self):
+        reload_eoxserver_config()
+        current_config = get_eoxserver_config()
+
+
+        reader = LayerMapperConfigReader(current_config)
+        self.assertIsNone(reader.min_render_zoom)

eoxserver/instance_template/project_name/conf/eoxserver.conf

@@ -40,7 +40,7 @@ instance_id={{ project_name }}
 [services.owscommon]
 #http_service_url    (mandatory) the URL where GET KVP and POST XML
 #                                OWS requests are expected
-http_service_url=http://localhost:8000/ows?
+http_service_url = ${DEFAULT:HTTP_SERVICE_URL}
 
 # time_interval_interpretation (optional) How to interpret time intervals.
 #                                         Allowed values are 'closed' and
@@ -99,7 +99,7 @@ mask_names=clouds
 
 # limit_products =
 # limit_mode = hide
-# min_render_zoom =
+min_render_zoom = ${DEFAULT:OWS_WMS_MINRENDER_ZOOM}
 # fill_opacity =
 # color = grey
 
@@ -128,7 +128,7 @@ mask_names=clouds
 supported_formats=image/tiff,image/jp2,application/x-netcdf,application/x-hdf
 
 # the maximum size of output coverages
-# maxsize = 2048
+maxsize = ${DEFAULT:OWS_WCS_MAXSIZE}
 
 [services.ows.wcs20]
 #paging_count_default (optional) Number of maximum coverageDescriptions