Build package for RHEL

Previously, when you had to build a package for RHEL you had to use epel-7-x86_64 chroot (or similar). This chroot is made of CentOS plus EPEL. This causes a problem when you want to use real RHEL for some reason. E.g., when new RHEL is out, but CentOS not yet.

To build for RHEL you have to Red Hat subscription. You can use your existing subscription or you can use free of charge subscription.

Register:

$ subscription-manager register (--serverurl subscription.rhsm.stage.redhat.com) \
 --username username \
 --password password

Check available pools:

$ subscription-manager list --all --available
...
Pool ID:  <THE_POOL_ID>
...

Obtain the keypair:

# subscription-manager attach --pool <THE_POOL_ID>
...

$ ls /etc/pki/entitlement
<KEY_ID>-key.pem  <KEY_ID>.pem

And try mock:

$ mock -r rhel-8-x86_64 --shell
...

Mock provides rhel-<RELEASEVER>-<TARGET_ARCH> configs which use pure RHEL. There are also rhel+epel-<RELEASEVER>-<TARGET_ARCH> configs which use RHEL plus EPEL.

If there are multiple client keys, mock takes the first one in glob(“/etc/pki/entitlement/-key.pem") output. But users still generate configure `config_opts['redhat_subscription_key_id']` in mock configuration, or on command line `--config-opts=redhat_subscription_key_id=`.