Add docker run script to change api url on startup

Dockerfile

@@ -8,9 +8,7 @@ COPY .  ./
 RUN \
   # Build the frontend
   yarn install --frozen-lockfile && \
-  yarn run build && \
-  # Override config
-  sed -i 's/http\:\/\/localhost\:3456\/api\/v1/\/api\/v1/g' dist/index.html
+  yarn run build
 
 # Stage 2: copy 
 FROM nginx
@@ -22,8 +20,11 @@ RUN apt-get update && apt-get install -y apt-utils openssl && \
   openssl x509 -req -days 3650 -in /etc/nginx/ssl/dummy.csr -signkey /etc/nginx/ssl/dummy.key -out /etc/nginx/ssl/dummy.crt
 
 COPY nginx.conf /etc/nginx/nginx.conf
+COPY run.sh /run.sh
 
 # copy compiled files from stage 1
 COPY --from=compile-image /build/dist /usr/share/nginx/html
 
-LABEL maintainer="maintainers@vikunja.io"
+LABEL maintainer="maintainers@vikunja.io"
+
+CMD "/run.sh"

run.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+# This shell script sets the api url based on an environment variable and starts nginx in foreground.
+
+if [ -z "$VIKUNJA_API_URL" ]; then
+  VIKUNJA_API_URL="/api/v1"
+fi
+
+# Escape the variable to prevent sed from complaining
+VIKUNJA_API_URL=$(echo $VIKUNJA_API_URL |sed 's/\//\\\//g')
+
+sed -i "s/http\:\/\/localhost\:3456\/api\/v1/$VIKUNJA_API_URL/g" /usr/share/nginx/html/index.html
+
+nginx -g "daemon off;"