task: add proxy configuration template

Author: Dominick Leppich

Dockerfile

@@ -12,6 +12,7 @@ COPY module-core/target/vocabulary-server-core.jar /opt/digiverso/vocabulary/
 COPY module-core/src/main/resources/application.properties /opt/digiverso/vocabulary/
 RUN sed -re "s|^(server.port=).*|\1${VOCABULARY_SERVER_PORT}|" \
      -e "s|^#?(security.token=).*|\1${VOCABULARY_SERVER_TOKEN}|" \
+     -e "s|^#?(server.forward-headers-strategy.*)|\1|" \
      -e "s|^(spring.datasource.username=).*|\1${VOCABULARY_DB_USER}|" \
      -e "s|^(spring.datasource.password=).*|\1${VOCABULARY_DB_PASSWORD}|" \
      -e "s|^(spring.datasource.url=).*|\1jdbc:mariadb://$VOCABULARY_DB_SERVER:3306/${VOCABULARY_DB_DATABASE}|" \

module-core/src/main/resources/application.properties

@@ -10,6 +10,12 @@
 # Control anonymous read operations. If set to false or not set, anonymous readers will not get access
 #security.anonymous.read-allowed=true
 
+# Proxy / Gateway configuration
+# If the vocabulary server is behind a proxy, it will possibly generate wrong URLs because it is called with an internal
+# IP or hostname. This can be controlled by X-Forwarded-* Headers (e. g. X-Forwarded-Host: example.com). To enable this,
+# uncomment the following line.
+#server.forward-headers-strategy=framework
+
 # Basic configuration
 # The port the vocabulary server should listen on
 server.port=8081