[DRAFT] Multiple instances of demo environment to showcase integrations

[maoo]

NOTE! This is still a draft, we should probably discuss it further during our next bi-weekly meeting; eager to hear your thoughts @DovOps @rocketstack-matt

Challenge

• Allow contributors to branch out the TraderX main version and showcase the code under demo.traderx.finos.org
• Optimise infrastructure (as code), in order to:
  1. Reuse services that are unaltered by the branch
  2. Run multiple TraderX "instances" using the same container "cluster", preferably using Docker Compose
• Allow contributors to keep on working independently on demo/* branches

Proposed approach

1. Release Docker images (on the main branch) into Docker Registry using Github actions
2. Docker compose points to the released docker images
3. Branches that are named with "demo/*" must:
4. clone, modify and release Docker images that need update, plus the "ingress" image
5. Update GitHub Actions to only release the images that have been customised; names must be different (ie prefixed with the branch name) than the ones in the main branch, to avoid overlap
6. Update docker-compose.yml to add all new images as services; for the ingress, a new port must be chosen, to avoid overlap
7. Update the main server Nginx configuration to add a match on domain name (ie cdm.traderx.finos.org) and redirect to the proper ingress image port