Add WHOOGLE_URL_PREFIX env var to support relative path redirection

The `WHOOGLE_URL_PREFIX` var can now be set to fix internal app
redirects, such as the `/session` redirect performed on the first visit
to the Whoogle home page.

Dockerfile

@@ -26,6 +26,7 @@ RUN mkdir -p $config_dir
 RUN chmod a+w $config_dir
 VOLUME $config_dir
 
+ARG url_prefix=''
 ARG username=''
 ARG password=''
 ARG proxyuser=''
@@ -45,6 +46,7 @@ ARG imgur_alt='farside.link/rimgo'
 ARG wikipedia_alt='farside.link/wikiless'
 
 ENV CONFIG_VOLUME=$config_dir \
+    WHOOGLE_URL_PREFIX=$url_prefix \
     WHOOGLE_USER=$username \
     WHOOGLE_PASS=$password \
     WHOOGLE_PROXY_USER=$proxyuser \

README.md

@@ -321,6 +321,7 @@ There are a few optional environment variables available for customizing a Whoog
 
 | Variable             | Description                                                                               |
 | -------------------- | ----------------------------------------------------------------------------------------- |
+| WHOOGLE_URL_PREFIX   | The URL prefix to use for the whoogle instance (i.e. "/whoogle")                          |
 | WHOOGLE_DOTENV       | Load environment variables in `whoogle.env`                                               |
 | WHOOGLE_USER         | The username for basic auth. WHOOGLE_PASS must also be set if used.                       |
 | WHOOGLE_PASS         | The password for basic auth. WHOOGLE_USER must also be set if used.                       |

app/routes.py

@@ -570,4 +570,7 @@ def run_app() -> None:
     elif args.unix_socket:
         waitress.serve(app, unix_socket=args.unix_socket)
     else:
-        waitress.serve(app, listen="{}:{}".format(args.host, args.port))
+        waitress.serve(
+            app,
+            listen="{}:{}".format(args.host, args.port),
+            url_prefix=os.environ.get('WHOOGLE_URL_PREFIX', ''))

charts/whoogle/values.yaml

@@ -24,6 +24,7 @@ serviceAccount:
   name: ""
 
 conf: {}
+  # WHOOGLE_URL_PREFIX: ""   # The URL prefix to use for the whoogle instance (i.e. "/whoogle")
   # WHOOGLE_DOTENV: ""       # Load environment variables in whoogle.env
   # WHOOGLE_USER: ""         # The username for basic auth. WHOOGLE_PASS must also be set if used.
   # WHOOGLE_PASS: ""         # The password for basic auth. WHOOGLE_USER must also be set if used.

whoogle.template.env

@@ -24,6 +24,9 @@
 #WHOOGLE_CSP=1
 #HTTPS_ONLY=1
 
+# The URL prefix to use for the whoogle instance (i.e. "/whoogle")
+#WHOOGLE_URL_PREFIX=""
+
 # Restrict results to only those near a particular city
 #WHOOGLE_CONFIG_NEAR=denver