i am having the same issue for installing vault on Redhat 7
rhel7.amazon-ebs.rhel7: fatal: [default]: FAILED! => {"changed": false, "msg": "Failure talking to yum: failure: repodata/repomd.xml from hashicorp: [Errno 256] No more mirrors to try.\nhttps://rpm.releases.hashicorp.com/RHEL/7Server/x86_64/stable/repodata/repomd.xml: [Errno 14] HTTPS Error 404 - Not Found"}