Make RACK UI use default config file which can be optionally overridden

.gitignore

@@ -68,7 +68,7 @@ cli/.project
 /Turnstile-Example/Turnstile-IngestionPackage/CounterApplicationImplementation/*.o
 /Turnstile-Example/turnstile-ingestion-package.zip
 rack-ui/cache/
-rack-ui/config/config.yml
+rack-ui/config/config-override.yml
 rack-ui/.project
 EntityResolution/.project
 EntityResolution/Resolutions/Summary.csv

rack-box/scripts/install.sh

@@ -94,7 +94,6 @@ echo "rackui ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/rackui
 mkdir /etc/rackui
 chown rackui.rackui /etc/rackui
 envsubst < rackui.service > /etc/systemd/system/rackui.service
-cp config/config.sample.yml config/config.yml
 systemctl enable rackui
 
 # Initialize SemTK environment variables

rack-ui/config/config-default.yml

@@ -0,0 +1,5 @@
+# RACK UI default configuration
+# Note: if config/config-override.yml is present, each of its entries will override the corresponding entry below
+
+# text to display as warning banner on load page (if empty string, no banner will appear)
+load-warning: ''

rack-ui/pages/helper.py

@@ -1,6 +1,7 @@
 
 """ Helper functions """
 
+import yaml
 import tempfile
 import traceback
 import dash
@@ -13,6 +14,21 @@
 
 # configuration
 SPARQLGRAPH_BASE_URL = "http://localhost:8080"
+CONFIG_FILE_DEFAULT = "config/config-default.yml"
+CONFIG_FILE_OVERRIDE = "config/config-override.yml"
+
+def get_config(key) -> str:
+    """ Load default config, override it with custom config if present """
+    # TODO read config once, store for subsequent use
+    with open(CONFIG_FILE_DEFAULT) as f:
+        config_obj = yaml.safe_load(f)
+    try:
+        with open(CONFIG_FILE_OVERRIDE) as f:
+            config_custom = yaml.safe_load(f)
+        config_obj.update(config_custom)  # override
+    except FileNotFoundError:
+        pass
+    return config_obj.get(key)
 
 def get_temp_dir() -> str:
     """ Get a temp dir """

rack-ui/pages/load.py

@@ -1,6 +1,5 @@
 """ Content for the "load data" page """
 
-import yaml
 import time
 import io
 import base64
@@ -21,8 +20,7 @@
 
 # get text for warning banner
 def get_warning_banner_str() -> str:
-    config_obj = yaml.safe_load(open("config/config.yml"))
-    return config_obj.get('load-warning')
+    return get_config('load-warning')
 
 # display strings
 CLEAR_BEFORE_LOADING_STR = "Clear before loading"