feature(docker-image): allow custom nginx port within container (#4086)

* Use PORT to override nginx listen port when defined
* Add dockerignore to make build context smaller

.dockerignore

@@ -0,0 +1,7 @@
+/.git
+/.github
+/dev-helpers
+/docs
+/src
+/swagger-ui-dist-package
+/test

Dockerfile

@@ -12,7 +12,7 @@ ENV OAUTH_REALM "**None**"
 ENV OAUTH_APP_NAME "**None**"
 ENV OAUTH_ADDITIONAL_PARAMS "**None**"
 ENV SWAGGER_JSON "/app/swagger.json"
-ENV PORT 80
+ENV PORT 8080
 ENV BASE_URL ""
 
 RUN apk add --update nginx

docker-run.sh

@@ -53,4 +53,7 @@ if [[ -n "$VALIDATOR_URL" ]]; then
   unset TMP_VU
 fi
 
+# replace the PORT that nginx listens on if supplied
+if [[ -n "${PORT}" ]]; then sed -i "s|8080|${PORT}|g" /etc/nginx/nginx.conf; fi
+
 exec nginx -g 'daemon off;'