Do you need a "cloud", as in a programmatic API to access and provision a pile of compute and storage? Or do you mean a "cloud" as in a bunch of locally hosted productivity tools?

The first case, creating a pool of resources with API access to deploy VMs, can be accomplished with something like CloudStack or OpenStack. This is what you would want if you are just handing off compute and storage resources for other teams to provision and deploy software on.

If you are managing internal IT resources and software, especially critical infrastructure like DNS, NTP, virtual routers/firewalls, identity management platforms, then you probably want a a hypervisor solution like Proxmox, or Nutanix or VMware if you have need of the extra features and have the budget for it.

My base infrastructure and productivity suite looks like this:

• Proxmox + Ceph for hypervisor and storage
• Red Hat IdM for directory services and PKI
• Chrony for NTP and Bind for internal/external resolvers
• Grafana / Prometheus / Loki for metrics and log ingestion, alerting, and dashboards
• Ansible for configuration management
• Caddy for edge proxies
• OPNsense for virtual routers
• Gitlab for source control and issue tracking, and I abuse scheduled CI/CD a bit as a distributed scheduler
• Keycloak for SSO auth to hosted apps
• Outline for wiki
• Grist for hybrid spreadsheet / database
• OwnCloud Infinite Scale for document management, integrated with OnlyOffice and Draw.io
• JetBrains YouTrack for project management
• Sharry for large file sharing externally