This commit implements multi-tenancy. A tenant is defined based on a value
from JWT claims. The key of this value must be specified in the configuration
file. This allows us to pick different values when using multiple SSOs.
Let me explain more in depth how this works:
Cloud API gets a new compose request. Firstly, it extracts a tenant name from
JWT claims. The considered claims are configured as an array in
cloud_api.jwt.tenant_provider_fields in composer's config file. The channel
name for all jobs belonging to this compose is created by `"org-" + tenant`.
Why is the channel prefixed by "org-"? To give us options in the future. I can
imagine the request having a channel override. This basically means that
multiple tenants can share a channel. A real use-case for this is multiple
Fedora projects sharing one pool of workers.
Why this commit adds a whole new cloud_api section to the config? Because the
current config is a mess and we should stop adding new stuff into the koji
section. As the Koji API is basically deprecated, we will need to remove it
soon nevertheless.
Signed-off-by: Ondřej Budai <ondrej@budai.cz>
