feat: Parametrize image registry

[olljanat]

Parametrize image registry so those who prefer Docker Hub can get images from there like this:

export CLOUDPODS_REPO=docker.io/yunion
export MARIADB_REPO=docker.io/library
docker compose pull

This does not change behavior for those who don't have those environment variables defined. Look more information from here

PS. Note that yunion/compose-service-init:v3.11.9 seems to be missing from Docker Hub and should be uploaded to there (latest is v3.11.4 at the moment).

[zexi]

@olljanat Thanks for the contribution. The compose files are generated by ./generate-compose.py script and you can use make generate-docker-compose-manifests and make generate-baremetal-compose-manifests to rewrite the docker-compose.yml files. So changing the repo here for cloudpods services and mysql repo here, and then regerating docker-compose.yml is more reasonable.

[olljanat]

@zexi Thanks for quick review. PR updated.

[zexi]

PS. Note that yunion/compose-service-init:v3.11.9 seems to be missing from Docker Hub and should be uploaded to there (latest is v3.11.4 at the moment).

@olljanat Thanks for pointing it out. I've uploaded the yunion/compose-service-init:v3.11.9 image.