Restarting docker-compose after running rake assets:precompile resets the changes - ruby-on-rails

Question

I'm currently trying to use Zammad Open Source, a helpdesk ticketing system with Docker-compose. However I have used it on a non-docker setup before and I edited the html views and added some logos and extra features that are required by my team. However we are needed to move into a docker-based instance soon due to reasons.
I succeeded in installing it normally, and the default compose file does mount an image when bringing the container up. After that I go and apply the changes as how I did on my existing setup. The changes require me to run
rake assets:precompile
and restart only the rails container. After restarting it, it works and the changes are reflected.
However, once I run
docker-compose restart
All the containers restart (as expected) but the rails server seems to discard every single change I made, and everything looks as if I just brought up a fresh container.
What I've tried:
Apply the changes, restart rails container, and commit the container into a custom image and pulled from it. Didn't work.
Edited dockerfile, entrypoint scripts to apply the changes and also run precompile during installation. Didn't work.
docker-compose.yml
version: '3'
services:
zammad-backup:
command: ["zammad-backup"]
depends_on:
- zammad-railsserver
- zammad-postgresql
entrypoint: /usr/local/bin/backup.sh
environment:
- BACKUP_SLEEP=86400
- HOLD_DAYS=10
- POSTGRESQL_USER=${POSTGRES_USER}
- POSTGRESQL_PASSWORD=${POSTGRES_PASS}
image: ${IMAGE_REPO}:zammad-postgresql${VERSION}
restart: ${RESTART}
volumes:
- zammad-backup:/var/tmp/zammad
- zammad-data:/opt/zammad
zammad-elasticsearch:
environment:
- discovery.type=single-node
image: ${IMAGE_REPO}:zammad-elasticsearch${VERSION}
restart: ${RESTART}
volumes:
- elasticsearch-data:/usr/share/elasticsearch/data
zammad-init:
command: ["zammad-init"]
depends_on:
- zammad-postgresql
environment:
- MEMCACHE_SERVERS=${MEMCACHE_SERVERS}
- POSTGRESQL_USER=${POSTGRES_USER}
- POSTGRESQL_PASS=${POSTGRES_PASS}
- REDIS_URL=${REDIS_URL}
image: ${IMAGE_REPO}:zammad${VERSION}
restart: on-failure
volumes:
- zammad-data:/opt/zammad
zammad-memcached:
command: memcached -m 256M
image: memcached:1.6.10-alpine
restart: ${RESTART}
zammad-nginx:
command: ["zammad-nginx"]
expose:
- "8080"
depends_on:
- zammad-railsserver
image: ${IMAGE_REPO}:zammad${VERSION}
restart: ${RESTART}
volumes:
- zammad-data:/opt/zammad
zammad-postgresql:
environment:
- POSTGRES_USER=${POSTGRES_USER}
- POSTGRES_PASSWORD=${POSTGRES_PASS}
image: ${IMAGE_REPO}:zammad-postgresql${VERSION}
restart: ${RESTART}
volumes:
- postgresql-data:/var/lib/postgresql/data
zammad-railsserver:
command: ["zammad-railsserver"]
depends_on:
- zammad-memcached
- zammad-postgresql
- zammad-redis
environment:
- MEMCACHE_SERVERS=${MEMCACHE_SERVERS}
- REDIS_URL=${REDIS_URL}
image: ${IMAGE_REPO}:zammad${VERSION}
restart: ${RESTART}
volumes:
- zammad-data:/opt/zammad
zammad-redis:
image: redis:6.2.5-alpine
restart: ${RESTART}
zammad-scheduler:
command: ["zammad-scheduler"]
depends_on:
- zammad-memcached
- zammad-railsserver
- zammad-redis
environment:
- MEMCACHE_SERVERS=${MEMCACHE_SERVERS}
- REDIS_URL=${REDIS_URL}
image: ${IMAGE_REPO}:zammad${VERSION}
restart: ${RESTART}
volumes:
- zammad-data:/opt/zammad
zammad-websocket:
command: ["zammad-websocket"]
depends_on:
- zammad-memcached
- zammad-railsserver
- zammad-redis
environment:
- MEMCACHE_SERVERS=${MEMCACHE_SERVERS}
- REDIS_URL=${REDIS_URL}
image: ${IMAGE_REPO}:zammad${VERSION}
restart: ${RESTART}
volumes:
- zammad-data:/opt/zammad
volumes:
elasticsearch-data:
driver: local
postgresql-data:
driver: local
zammad-backup:
driver: local
zammad-data:
driver: local

Answer 1

I found a solution after a few headaches here and there:
What I did:
Dove in the files and found out that it pulls an image from github, downloaded the image. After extracting the tar.gz file, I applied all the changes that i needed, repacked the tar.gz, and edited the dockerfile to point to the new image.
After that, i need to force docker-compose to rebuild the image. Then the changes are persistent even after restarts.